Global Zoonotic Diseases: Bacterial and Rickettsial Diseases
Disease in Humans | Causative Organism | Animals Involved | Geographic Distribution | Probable Means of Transmission to Humans | Clinical Manifestations in Humans |
|---|---|---|---|---|---|
Bacterial Diseases | |||||
Bacillus anthracis | Mainly noted in production animals (cattle, sheep, goats, horses, water buffalo, camelids) and wild herbivores; however, virtually all mammals are susceptible to high doses. A few cases have been noted in birds. | Worldwide but distribution is focal; common in Africa, Asia, South America, Middle East, parts of Europe | Occupational contact exposure (abraded skin, mechanical transmission by biting flies, other routes); ingestion or foodborne, rarely airborne | Early signs vary with route of inoculation; papule to ulcerative skin lesions; mild to severe gastroenteritis ± hematemesis, bloody diarrhea, ascites (abdominal GI form); sore throat, dysphagia, fever, neck swelling, mouth lesions (oropharyngeal GI form); pneumonia; all may progress to sepsis, meningitis; untreated cases fatal in 5%–30% (cutaneous) to 100% (inhalation) | |
Arcobacter infections | Arcobacter butzleri, A cryaerophilus, A skirrowii, possibly others | Poultry, cattle, pigs, sheep, horses, shellfish; some studies have detected these organisms in dogs and cats | Worldwide | Ingestion of contaminated water, undercooked meat (especially poultry) has been suggested | Gastroenteritis; bacteremia, mainly in patients with chronic illnesses; endocarditis, peritonitis; emerging and incompletely understood |
Bordetellosis ( see Respiratory Diseases of Pigs and see Bordetellosis in Poultry) | Bordetella bronchiseptica, B hinzii | B bronchiseptica in dogs, rabbits, cats, pigs, guinea pigs, other mammals; B hinzii mainly in poultry, uncommonly mammals (eg, rabbits, rodents) | Worldwide; uncommon in humans | Exposure to saliva or sputum, aerosols | Sinusitis, bronchitis, pertussis-like illness; pneumonia and disseminated disease (eg, endocarditis, peritonitis, meningitis), usually in immunocompromised; biliary infections; wound infection; abscesses |
Lyme disease (Lyme borreliosis) | Borrelia burgdorferi sensu lato complex (B burgdorferi sensu stricto, B garinii, B afzelii, B spielmanii, possibly others) | Wild rodents, insectivores, hedgehogs, hares, other mammals; birds are reservoirs for some agents (eg, B garinii); possibly some lizards | Agents exist worldwide where Ixodes ticks are found; human cases have been reported in North America, Europe, Australia, parts of Asia, Amazon region of South America | Ixodes spp bites | Nonspecific febrile illness early; erythema migrans ("target-like") skin lesions in many; may progress in some humans to arthritis, neurologic, cardiac, and/ or skin signs (acrodermatitis chronica atrophicans); syndromes may vary with infecting agent |
Tickborne relapsing fever | B recurrentis, B crocidurae, B turicatae, B hermsii, B persica, B hispanica, others; some species such as B duttoni are human pathogens and not zoonotic | Wild rodents, insectivores, possibly birds | Africa, Asia, Europe, Americas; species varies with region | Tick bites (mainly Ornithodoros spp) | High fever, malaise, headache, myalgia, chills; neurologic signs or abortion possible; jaundice, epistaxis, major organ dysfunction possible; recurring episodes, often milder, after a symptom-free period; death in 2%–5% |
Borrelia miyamotoi disease | Borrelia miyamotoi | Rodents, birds, possibly larger mammals | Asia, Europe, North America, probably other locations | Tick bites (Ixodes spp) | Fever, nonspecific flu-like signs including GI signs in some, rash, thrombocytopenia; meningoencephalitis in immunocompromised |
Brucellosis ( See also page Brucellosis in Large Animals and See also page Brucellosis in Dogs) | Brucella abortus | Cattle, water buffalo, American bison, African buffalo, elk are reservoir hosts; numerous mammalian spillover hosts (eg, deer, sheep, goats, camels, South American camelids, pigs, canids, felids, horses) | Once worldwide, now eradicated or uncommon in domestic animals in some countries or regions; reservoirs in wildlife in some disease-free areas including the US | Exposure to birth products from animals, ingestion (especially unpasteurized dairy products or undercooked meat), contact with mucous membranes and broken skin, accidental inoculation of strain 19 vaccine; rare instances of person-to-person transmission (eg, assisting at a birth from an infected woman, in a blood transfusion, or during sexual intercourse) | Extremely variable, subacute and undulant to sepsis; often nonspecific febrile illness with drenching sweats early; arthritis, spondylitis, epididymo-orchitis, endocarditis, neurologic and , various other syndromes if chronic; case fatality 1%–2% in untreated |
B melitensis | Goats, sheep are the primary hosts; can infect various mammalian spillover hosts (eg, cattle, water buffalo, camelids, dogs, pigs, wild ungulates) | Parts of Asia, Africa, Middle East, Europe and Latin America including Mexico | As for B abortus; accidental inoculation of Rev 1 vaccine | As above; this species is considered highly pathogenic for humans | |
B suis biovars 1–4; biovar 5 has not been reported in humans | Swine and wild pigs (biovars 1, 2, 3), European hares (biovar 2 in Europe, possibly biovar 1 in South America), reindeer and caribou (biovar 4); B suis also in some other mammals | Biovars 1 and 3 worldwide in swine-raising regions except eradicated or nearly eradicated from domestic pigs in some countries; biovar 2 in wild boar in Europe; biovar 4 in Arctic regions of North America and Eurasia | As for B abortus; food sources may include uncooked caribou bone marrow (biovar 4) | As above | |
B canis | Dogs; evidence of infection in wild canids including coyotes, foxes | Worldwide except in a few regions (Australia, New Zealand); not common in humans | Probably as for B abortus; close contact, especially with animals that recently aborted or gave birth | Probably as above | |
B ceti and ST27 genotype from marine mammals, possibly B pinnipedialis | Marine mammals (B ceti mainly in cetaceans, B pinnipedialis mainly in pinnipeds) | Probably occur in most or all marine environments | Laboratory exposure; sources of other infections unknown (possibly contact with animals or exposure to seawater, seafood); rare or underdiagnosed in humans | Few cases known: mild to severe febrile illness, similar to that due to other Brucella spp; neurological signs occurred in some patients | |
B neotomae, B inopinata; additional species of Brucella maintained in wild animals might also be human pathogens | B neotomae in desert wood rat (Neotoma lepida) and possibly other rodents. Host of B inopinata unknown. | Uncertain. Two human cases due to B neotomae were acquired in South America | Unknown | Probably similar to cases due to other species of Brucella. Two cases due to B neotomae had neurological signs as well as other brucellosis symptoms. B inopinata was isolated from 1) an infected breast implant, possibly after a systemic infection, and 2) the lungs in a case of chronic pneumonia. | |
C jejuni, C coli, occasionally other species; some strains of C jejuni seem to have broader host ranges than others | Poultry, cattle, swine, dogs, cats, rodents, other mammals, wild birds | Worldwide | Foodborne (especially poultry and other meats, unpasteurized dairy products); waterborne; contact with infected animals (fecal-oral route) | Gastroenteritis from mild cases to fulminating or relapsing colitis; occasional sequelae such as reactive arthritis; occasionally, other syndromes, including sepsis | |
Campylobacter fetus infection | C fetusfetus (most cases), C fetustestudinum; possibly C fetusvenerealis | C fetusfetus and Cvenerealis in cattle, sheep, goats (human-adapted lineages also seem to exist); C fetustestudinum in reptiles | Worldwide | Probably direct contact or ingestion; often unknown | Opportunist; sepsis, meningitis, endocarditis, abscesses, other systemic infections in elderly, immunocompromised, or infants; abortions, preterm births in pregnant women, neonatal sepsis; gastroenteritis not prominent in most cases |
Capnocytophaga infection | C canimorsus, C cynodegmi, C canis (rare), possibly others | Dogs, cats | Probably worldwide | Bites or scratches | Fever, localized infections to bacteremia or sepsis, endocarditis, meningitis; often in immunocompromised or elderly |
Cat scratch disease | Bartonella henselae; B clarridgeiae and other Bartonella species also implicated rarely in cat scratch disease or other conditions (eg, endocarditis) | Cats and other felids; other Bartonella spp in canids, rodents, rabbits, other animals | Worldwide | Often associated with scratches, bites, especially from cats; potential for other exposures to broken skin via saliva; exposure of conjunctiva | Lymphadenopathy (may be absent in elderly), fever, malaise, skin lesions at inoculation site in immunocompetent, usually self-limiting with complications (eg, endocarditis, neuroretinitis, neurologic disease) uncommon; inoculation into eye results in conjunctivitis ± ocular granuloma and local lymphadenopathy; risk of bacteremia, disseminated disease, bacillary angiomatosis in immunosuppressed |
Chlamydiosis (see also Psittacosis) | Chlamydia abortus; C felis, C suis, C pecorum involved or suspected in a few cases | C abortus reservoirs are sheep, goats; C pecorum found in ruminants, horses, pigs, others; C felis mainly in cats; C suis mainly in suids; Chlamydia spp also infect mammals other than their usual hosts, occasionally reptiles, amphibians, possibly birds | C felis, C suis, C pecorum are cosmopolitan; C abortus in most sheep-raising areas but not Australia or New Zealand | Contamination of mucous membranes, inhalation and possibly other routes after contact with animals; C abortus in high concentrations in birth products but chlamydiae also occur in other secretions and excretions | C abortus: mainly abortions, stillbirths, preterm births, often associated with illness including septicemia in mother; respiratory disease and possibly other conditions in nonpregnant (few cases); other chlamydiae suggested to be involved rarely in various illnesses including C felis in conjunctivitis suspected agent of keratoconjunctivitis, also implicated in other conditions (controversial) |
Clostridium difficile; some genotypes in animals are shared with humans and implicated as potential zoonoses | Cattle, pigs, dogs, and other species | Worldwide | Possible zoonosis; from contact or ingestion in contaminated meat; also from environment and contact with infected humans | Gastroenteritis, varying in severity from diarrhea to fulminant colitis, usually in conjunction with antimicrobial use | |
Clostridium perfringens, type A (most common), C, or D; environmental or endogenous source, with some potential for zoonotic transmission | Domestic and wild animals, humans | Worldwide | Foodborne (usually type A); nonfood-associated intestinal infection; wound contaminant, usually environmental; may be endogenous in debilitated from GI or urogenital tract | Foodborne gastroenteritis, usually brief, self-limited except in debilitated; nonfood-related intestinal infection with prolonged diarrhea, sometimes bloody, mainly in elderly after antimicrobials; life-threatening necrotic enteritis, often in debilitated; gas gangrene, sepsis; necrotic enteritis, gas gangrene, sepsis are fatal if not treated | |
Corynebacterium ulcerans, C pseudotuberculosis, and C bovis infections | C ulcerans, C pseudotuberculosis, C bovis | C ulcerans in cattle, pigs, small ruminants, dogs, cats, ferrets, other domestic and wild animals; C pseudotuberculosis in sheep, goats, cattle, horses, camelids, other mammals; C bovis in cattle, colonies of immunocompromised laboratory rodents | Probably worldwide; uncommon in humans but may be increasing | Direct contact, consumption of unpasteurized milk products | Acute upper respiratory illness with sinusitis, sore throat, tonsillitis, or more severe pharyngitis resembling diphtheria (pseudomembranous pharyngitis); cardiorespiratory complications including pneumonia possible; peritonitis; isolated skin infection; ocular disease (C bovis) and other localized conditions; some cases serious or fatal |
Dermatophilus congolensis | Cattle, horses, deer, sheep, goats, other mammals | Worldwide, especially in warmer regions | Usually direct contact with lesions; mechanical transmission on fomites possible | Pustular desquamative dermatitis, other skin lesions | |
Enterohemorrhagic and enteroaggregative Escherichia coli infections | E coli O157:H7, O157:H-, members of O26, O55, O91, O103, O111, O121, O145 and other serogroups | Especially cattle, sheep; also found in goats, bison, camelids, cervids, pigs, lagomorphs, many other of mammals; sometimes shed by birds | Worldwide | Ingestion of undercooked meat (especially ground beef), unpasteurized milk products, vegetables, other food sources or water contaminated with feces; direct contact with feces, animals (especially ruminants) or contaminated fomites | Diarrhea or hemorrhagic colitis; a minority of patients with hemorrhagic colitis develop hemolytic uremic syndrome (HUS); case fatality rate for HUS is 3%–5%, higher in some populations (eg, 1%–10% in children, up to 50% in elderly) |
Erysipelothrix rhusiopathiae | Swine, sheep, cattle, rodents, marine mammals; many other domestic and wild mammals and marsupials, birds (including poultry), reptiles, fish, mollusks, crustaceans | Worldwide | Contact with animal products; via skin, usually after scratch or puncture wound; contaminated soil (survives for weeks to months) | Localized cellulitis, usually self-limiting, often on hands; generalized skin lesions (uncommon); septic arthritis, often in finger joints near skin lesion; endocarditis (with high mortality, 38%); generalization with sepsis, other syndromes uncommon and often in immunocompromised | |
Burkholderia mallei | Equids are reservoirs; many other domesticated and wild mammals also susceptible to infection, clinical cases reported occasionally, especially in felids | Middle East, Asia, Africa and South America | Contact with infected animals, tissues through broken skin, mucous membrane, ingestion, inhalation | Mucous membrane or skin lesions; pneumonia and pulmonary abscess; sepsis; chronic abscesses, nodules, ulcers in many organs, weight loss, lymphadenopathy; case fatality rate varies with form, but > 95% in untreated septicemia and 90%–95% in untreated pulmonary disease | |
Helicobacter infection | H pullorum, H canis,H suis, other species suspected as zoonoses | Poultry (H pullorum), rodents (H pullorum and other species), pigs (H suis), dogs (H canis), many other mammals | Uncertain; possibly ingestion of undercooked meat or direct contact | Gastroenteritis or diarrhea, liver disease; cellulitis; bacteremia in immunosuppressed patients | |
Mycobacterial infections (leprosy) | Mycobacterium leprae | Armadillos; nonhuman primates (rare) | Armadillos in parts of southern US, Mexico, South America; nonhuman primates in Africa, possibly other locations; only human reservoirs in other areas | Transmission of animal leprosy to humans likely | Various skin lesions, sensory nerve lesions and deficits, nasal mucosal lesions; mild, self-limiting to progressive destruction |
Leptospira spp | Domestic and wild animals; reservoir hosts include rodents, dogs, cattle, pigs, farmed red deer, others | Worldwide | Occupational and recreational exposure, or exposure to rodent-contaminated material in urban locations; especially skin, mucous membrane contact with contaminated urine, infected fetuses, or reproductive fluids; water- and foodborne | Asymptomatic to severe, sometimes biphasic; nonspecific febrile illness followed by aseptic meningitis or icteric form (especially liver, kidney, CNS involvement, hemorrhages possible); pulmonary hemorrhage and edema, other syndromes; uveitis can be sequela; case fatality rate varies with syndrome (uncommon in aseptic meningitis, 5%–15% in icteric form, 30%–60% in severe pulmonary form) | |
Listeria monocytogenes, rarely Listeria ivanovii or other species of Listeria | Numerous mammals including marsupials, some birds and reptiles; subclinical fecal shedding has been reported in fish and amphibians; crustaceans can be contaminated | Worldwide | Most often foodborne, especially unpasteurized dairy products and various ready-to-eat refrigerated foods (eg, patés, deli meats); however, also many other sources including raw meat and fish, vegetables and fruits, foods contaminated after processing; ingestion of contaminated water, soil; direct contact with infected animals (via mucous membranes, broken skin as well as ingestion); transmission can occur between newborns in hospitals but person-to-person transmission otherwise absent or negligible | Acute, self-limited febrile gastroenteritis or mild, flu-like illness; ocular disease, conjunctivitis; abortion, premature or septicemic newborn if infected during pregnancy; meningitis, meningoencephalitis, septicemia in elderly, immunosuppressed, and infants; bone and joint infections in humans with implants; papular or pustular rash ± fever, chills in healthy adults after handling infected fetuses or other heavily contaminated source; occasionally other syndromes | |
Melioidosis (pseudoglanders) | Burkholderia pseudomallei (other species of soil-associated Burkholderia, (eg, B oklahomensis sp nov in North America, rarely linked to similar human diseases) | Sheep, goats, swine; occasional cases in many other terrestrial and aquatic mammals; also reptiles; some birds including psittacines, ratites, chickens; tropical fish | Mainly reported in parts of Asia and northern Australia; however, organisms or cases also documented in Africa, South America, Middle East, Caribbean; B pseudomallei is not known to exist in North America but a few cases that appeared to be indigenous were documented, source of organism uncertain | Via broken skin, inhalation, and ingestion; organisms live in soil and surface water; most cases are acquired from environment; direct transmission from animals is possible | Mimics many other diseases; acute localized infections, including skin lesions, cellulitis, abscesses, corneal ulcers; pulmonary disease, septicemia, internal organ abscesses; often occurs in immunocompromised; case fatality rate varies with form, > 90% in untreated septicemia |
Methicillin-resistant Staphylococcus aureus (MRSA) infections | S aureus that carry mecA or mecC gene; some strains maintained in animals (eg, production animals-associated CC398), other strains mainly in humans but animals can become carriers | Pigs (major reservoirs for production animals-associated strain CC398); cats, dogs mainly acquire strains from humans; MRSA also reported in other mammals, including horses, cattle; birds, including poultry, psittacines; turtles | Worldwide; can be reverse zoonosis or zoonosis; major strains in animals can vary with region | Usually by direct contact (typically with subclinically affected carrier animals); other routes also described; can be nosocomial in hospitals | Opportunist; localized skin and soft-tissue infections, invasive disease including septicemia, toxic shock syndrome; mortality varies with syndrome and success in finding antimicrobial |
Mycobacterium avium complex | Many species of mammals, some birds | Worldwide | Environmental, mainly from water, or soil; infection common to humans and animals | Soft-tissue and bone infections; cervical lymphadenitis; pulmonary disease, often in immunocompromised or those with preexisting lung conditions; disseminated in immunocompromised, especially AIDS patients with uncontrolled disease | |
Mycobacteria other than tuberculosis (eg, M simiae, M kansasii, , M genavense, M chelonae, M marinum, M ulcerans, others) | Ruminants; swine, cats, dogs, other mammals, amphibians, reptiles (uncommon), fish; species of Mycobacterium spp varies with host | Worldwide; distribution varies with the organism | Environmental, from water or soil | Same syndromes as M avium complex; some organisms tend to be associated with certain syndromes (eg, M marinum, M ulcerans, with ulcerative or nodular dermatitis) | |
Yersinia pestis | Rodents (eg, squirrels, prairie dogs, rats) and lagomorphs (pikas in Asia) are main reservoir; many mammals can be incidental hosts; cats and wild felids especially susceptible | Foci in North and South America, Asia, Middle East, and Africa | Flea bites, aerosols, handling infected animals or tissues (contact with broken skin or mucous membranes), bites, eating uncooked infected tissues | Febrile flu-like syndrome with swollen, very painful draining lymph node(s) (bubos); pneumonia; GI signs associated with foodborne outbreak; sepsis can occur in either bubonic or pneumonic form; case fatality rate in untreated 40%–70% (bubonic) to 100% (pneumonic); < 5% mortality if bubonic form treated early | |
Chlamydia psittaci, possibly other avian chlamydiae (eg, C gallinacea, C avium) | C psittaci in psittacines, pigeons, poultry, game birds, ratites and other domestic or wild birds; occasionally in mammals, possibly reptiles; C gallinacea in various poultry; C avium in pigeons, other birds | Worldwide | Direct contact with birds, inhalation of contaminated dust, feathers or aerosolized secretions or excretions from environment | Influenza-like febrile illness, with or without respiratory signs, that may progress to pneumonia; reproductive losses (abortion, premature birth); keratoconjunctivitis; endocarditis, myocarditis, meningoencephalitis, hepatitis, renal disease and other organ dysfunction, sepsis possible in severe cases; sometimes fatal if untreated, < 1% mortality with treatment | |
Rat bite fever | Streptobacillus moniliformis | Rodents, especially rats; might also be transmitted by carnivores (eg, dogs, cats, ferrets), which are probably infected or transiently colonized from rodents | Probably worldwide | Bites and scratches; handling or kissing a rodent, exposure to rodent urine; can be waterborne or foodborne | Febrile illness, often with rash; GI signs possible and especially common when foodborne polyarthritis/ polyarthralgia (usually but not always sterile) common, can persist for several months or more; other complications including hepatitis, endocarditis, focal abscesses, sepsis possible if untreated; overall case fatality rate 7%–13% if untreated |
Spirillum minus | as above | Seems to be common only in Asia but cases have been attributed to this organism on other continents | Mainly bites and scratches | As above; however, indurated, often ulcerated lesion at inoculation site; can relapse; some (minority) may have distinctive rash (large violaceous or reddish macules); polyarthritis is uncommon; overall case fatality rate 7%–10% if untreated | |
Salmonella enterica and S bongori (> 2,500 serovars) | Widespread in mammals, birds, reptiles, amphibians, including domestic species; also in crustaceans; higher-risk pets for human exposure may include reptiles, amphibians, young poultry, some exotic mammals, including hedgehogs | Worldwide | Foodborne infection or fecal-oral; some cases of occupational and recreational exposure | Gastroenteritis to sepsis; focal infections possible; especially severe in the elderly, young children, or immunocompromised | |
Streptococcal infections | Streptococcus spp, including S suis, S equi zooepidemicus, S canis, S iniae, S halichoeri, probably others | S suis in swine and wild boar; S equi zooepidemicus in horses; S canis in dogs, cats; S iniae and S halichoeri in fish (S halichoeri has affected various marine and terrestrial mammals including dogs, mink, farmed foxes, wild badger); each species can also be found in other animals | Streptococcus spp worldwide, but some organisms documented in limited locations (eg, S halichoeri in Europe) | Ingestion, especially of unpasteurized dairy products, undercooked animal tissues; direct contact, often through broken skin | Skin and soft-tissue infections; pharyngitis; other conditions, including pneumonia, meningitis, arthritis, endocarditis, streptococcal toxic shock syndrome, sepsis |
Tuberculosis (see alsoMycobacteriosis) | Mycobacterium bovis | Cattle, bison, African buffalo, some cervids (elk, white-tailed deer), brushtail opossums, European badgers, wild boar, Kafua lechwe can be reservoirs; many other mammals can be spillover hosts, rare reports in birds | Once worldwide, now eradicated or rare in some countries | Ingestion (unpasteurized dairy products, undercooked meat), inhalation, contamination of breaks in the skin | Skin lesions, cervical lymphadenitis pulmonary disease; can also affect genitourinary tract, bones, joints, CNS, intestinal tract and other sites; disseminated disease possible, especially in immunocompromised or young children; slow progression in most healthy humans and low mortality if treated, but CNS disease, disseminated disease, and immunocompromised patients have higher fatality rates |
Mycobacterium caprae | Goats are main reservoir; cattle, wild red deer may also maintain organism; also infects other mammals (eg, sheep, pigs, wild boar, horses, cervids, camels, foxes, zoo animals) | Reported mainly in Europe; also found in China, North Africa and may occur in other countries | Probably similar to M bovis | Similar to M bovis | |
Mycobacterium microti | Rodents, insectivores are reservoir; can occur in many other wild or domestic animals including cats, dogs, ferrets, production animals | Widely distributed | Probably similar to M bovis | Probably similar to M bovis | |
Mycobacterium orygis | Oryx, African buffalo, waterbuck, rhinoceros, nonhuman primates and other species | Africa, southern Asia, Middle East | Probably similar to M bovis | Probably similar to M bovis | |
Mycobacterium pinnipedii | Seals and sea lions are usual hosts; also reported in cetaceans and various terrestrial mammals (eg, cattle, camelids, nonhuman primates) | Coasts of Europe, South America, New Zealand, Australia, probably other locations | Probably similar to M bovis | Probably similar to M bovis | |
Francisella tularensis (some subspecies of this organism seem to be more virulent than others); other species of Francisella (eg, F hispaniensis, F philomiragia) can also cause illness but might mainly affect the immunocompromised | Lagomorphs, rodents, cats, sheep, many other mammals, birds, reptiles, fish; often in wild animals | F tularensistularensis almost exclusively in North America; F tularensisholarctica in Northern Hemisphere and Australia; F tularensismediasiatica in Central Asia; F tularensisnovicida reported in North America, Thailand; F hispaniensis in Europe (Spain) and Australia | Contact with mucous membranes, broken skin; insect bites (tabanids, mosquitoes, hard ticks); fomites; ingestion in food or water; inhalation | Nonspecific febrile illness, lymphadenitis; ulcerative skin lesions, exudative pharyngitis and stomatitis, conjunctivitis, gastroenteritis, respiratory signs or pneumonia, sepsis; case fatality rate 5% (localized disease, untreated) to > 50% (untreated typhoidal form or severe respiratory disease); 1%-–3% case fatality overall when treated | |
Vibriosis | Vibrio parahaemolyticus | Marine and estuarine shellfish, fish; also environmental in aquatic environments | Worldwide | Ingestion, wound infections | Gastroenteritis; dysentery (especially in some geographic regions); wound infections (mild to severe, including necrotizing fasciitis); sepsis; severe wound infections and sepsis usually in immunocompromised or those with liver disease (case fatality rate for sepsis 29%) |
V vulnificus | Marine shellfish, crustaceans (eg, shrimp), fish; also environmental in aquatic environments | Worldwide; human cases have been reported in North America, Europe, Asia | Ingestion (often raw oysters), wound infection from water or handling hosts | Wound infections from mild, self-limited lesions, bullae to cellulitis, myositis; necrotizing fasciitis; gastroenteritis; sepsis, usually in immunocompromised or those with liver disease, other debilitating illnesses; case fatality rate for sepsis > 50%, and up to 25% for wound infections | |
Vibriosis | V cholerae O1/O139 (epidemic strains) | Oysters, crabs, shrimp, mussels can act as a reservoir for organisms although most cases are acquired from humans | Rare or absent to epidemic in different regions; one focus along US Gulf Coast in shellfish | Ingestion | Mild to severe, voluminous diarrhea, vomiting, dehydration; severe cases fatal if untreated; however, low mortality if treated |
V cholerae non-O1/O139 (nonepidemic strains) | Oysters, other seafood, fish; also environmental in aquatic environments | Worldwide | Ingestion, wound infection | Gastroenteritis, usually mild and self-limited; wound infections; septicemia, usually in immunosuppressed or those with liver disease (case fatality rate for sepsis 47%–60% or higher) | |
Yersiniosis | Yersinia pseudotuberculosis | Many species of mammals, including production animals, dogs, cats, lagomorphs, rodents, wild and zoo mammals, birds, possibly reptiles | Agent probably worldwide; prevalence may vary between regions | Ingestion of contaminated water, food (including meat, vegetables); fecal-oral (animal contact); dog bite (rare) | Gastroenteritis (enterocolitis); pseudoappendicitis (with mesenteric lymphadenitis, terminal ileitis, fever, abdominal pain); severe GI bleeding possible in some cases of colitis; pharyngitis; sequelae may include erythema nodosum, reactive arthritis; sepsis, especially in elderly or immunocompromised; occasionally other syndromes, eg, septic arthritis, Far Eastern scarlet-like fever |
Y enterocolitica; not all serotypes are pathogenic | Many domestic and wild mammals, including rodents; some birds, reptiles, amphibians; pigs are a major source of zoonotic organisms, pathogenic types also occur in dogs, cats | Worldwide; prevalence of human disease may vary between regions | Ingestion, as for Y pseudotuberculosis (pork is a common source), animal contact | Gastroenteritis sometimes bloody; pseudoappendicitis; sequelae may include erythema nodosum, reactive arthritis; myocarditis, other syndromes; sepsis possible | |
Rickettsial Diseases | |||||
Human ewingii ehrlichiosis (formerly granulocytic ehrlichiosis) | Ehrlichia ewingii | Dogs, deer proposed | Parts of North and South America, Africa; closely related organism in Asia | Ticks, including Amblyomma americanum | Few cases described; fever, headache, malaise, myalgia, nausea, vomiting (rash seems to be uncommon); probably mild in most healthy people; many patients were immunosuppressed |
Human monocytic ehrlichiosis | Ehrlichia chaffeensis | Cervids, other domestic and wild mammals | North and South America, Asia, Africa; evidence for E chaffeensis or related organism in Europe | Ticks, including Amblyomma americanum | Asymptomatic to nonspecific febrile illness; rash in many pediatric cases, some adults; may progress to prolonged fever, renal failure, respiratory distress, hemorrhages, cardiomyopathy, neurologic signs, multiorgan failure; more severe in immunosuppressed, elderly; estimated case fatality rate 1% |
Human granulocytic anaplasmosis (formerly human granulocytic ehrlichiosis) | Anaplasma phagocytophilum (formerly Ehrlichia phagocytophilum and E equi) | Wild rodents, deer and other wild ungulates; production animals may be reservoirs; many other animals can also be infected | Worldwide | Tick bites (Ixodes spp), possibly exposure to blood or tissues from infected animals | Resembles human monocytic ehrlichiosis; often asymptomatic to mild in immunocompetent; rash uncommon; estimated case fatality rate < 1% |
Infection by other Ehrlichia species | E canis, other organisms (eg, Emuris-like organism, possibly E ruminantium) implicated rarely in human illness | Dogs and other canids thought to be reservoirs; for E canis also reported in other animals including felids, camels, cattle, racoons, | E canis worldwide | Ticks | Rare cases of febrile illness, in both healthy and immunosuppressed |
Q fever (Query fever) | Coxiella burnetii | Sheep, cattle, goats, cats, dogs, deer, rodents, small mammals, other domestic and wild mammals, birds | Cosmopolitan | Mainly airborne; exposure to placenta, birth tissues, animal excreta; occasionally ingestion (including unpasteurized milk); possibly tickborne infections | Febrile influenza-like illness; atypical pneumonia, hepatitis, occasionally other syndromes; persistent, localized infection of blood vessels, heart valve or other tissues, usually in those with pre-existing damage; possible pregnancy complications; overall case fatality rate 1%–2% if untreated |
Sennetsu fever | Neorickettsia sennetsu | Uncertain, possibly fish | Japan, Malaysia, Laos, possibly other Asian countries | Possibly ingestion of raw fish | Relatively mild, nonspecific, febrile illness, resembles infectious mononucleosis |
Spotted fever group of Rickettsia | |||||
—African tick bite fever | R africae | Cattle, other domestic and wild ungulates | Sub-Saharan Africa, eastern Caribbean | Bite of infected tick (mainly Amblyomma spp, possibly some Rhipicephalus spp | Nonspecific febrile illness; painful regional lymphadenopathy, stiffness and pain of neck muscles common; eschars often multiple; sometimes sparse maculopapular or vesicular rash; complications rare and deaths apparently absent or very rare |
—Mediterranean spotted fever; Boutonneuse fever; Israeli spotted fever, Astrakhan spotted fever, Indian tick typhus | R conorii | Rabbits, possibly rodents, dogs implicated as reservoirs for R conoriiconorii in Mediterranean; other animals can be infected | Europe, Africa, Asia | Bite of infected ticks (mainly Rhipicephalus spp), crushing tick | Nonspecific febrile illness; eschar (typically single) may or may not be present; rash, in most; complications including neurologic signs, cardiac involvement, multiorgan dysfunction, retinitis possible but uncommon; case fatality rate 1%–3% if untreated; R conorii subsp. israelensis might be more virulent |
—Fleaborne spotted fever; cat flea typhus | R felis (synonym ELB agent) | Dogs seem to be a reservoir host; evidence for organisms in cats and diverse other domestic and wild mammals | Cosmopolitan | Flea bites; mainly associated with Ctenocephalides felis (cat flea), also infects C canis and other fleas; possibly other arthropods | Febrile illness; rash in some; eschar may be uncommon; most cases seem to be mild but complications including CNS involvement, pneumonia; deaths possible |
—Queensland tick typhus | R australis | Bandicoots, rodents | Australia | Bite of infected Ixodes tick, especially I holocyclus, I tasmani | Febrile illness, eschar may be present, rash (either maculopapular or vesicular) in most; mild in most, but serious complications, death possible |
—Rickettsial pox | R akari | Mice; also rats, Korean voles | Organism may be cosmopolitan; human cases seem to be uncommon, mainly reported in a few locations in North America, Europe | Bite of infected rodent mites, Liponyssoides sanguineus | Eschar (single) in most; febrile illness; maculopapular rash progresses to vesicular, pustular, resembles chickenpox; self-limiting |
—Rickettsia parkeri rickettsiosis | R parkeri | North and South America | Bite of infected Amblyomma spp ticks | Resembles Rocky Mountain spotted fever (RMSF) but seems to be milder in most cases; and eschars common (may be multiple), petechial rash does not seem characteristic | |
R rickettsii | Rodents, rabbits, opossums, and other small mammals might amplify; dogs can be infected | North and South America | Bite of infected ticks; especially Dermacentor variabilis, D andersoni (in North America); Amblyomma spp, D nitens in South America; Rhipicephalus sanguineus also a vector in some areas; from crushing tick | Moderate to severe febrile illness; macular to generalized petechial rash; edema in some; usually no eschar; neurologic, pulmonary, hemorrhagic, and kidney signs in some; sepsis; gangrene; case fatality rate 15%–30% or higher if untreated, might be more severe in Brazil | |
—Tickborne lymphadenopathy; Dermacentor necrosis-erythema-lymphadenopathy | R slovaca, R raoultii | Uncertain; wild boar may be involved | Europe to Central Asia | Bites of infected ticks;Dermacentor marginatus, and other species | Eschar, local lymphadenopathy; localized alopecia at bite site; mild illness, fever and rash uncommon; no deaths reported |
—Other tickborne species in spotted fever group | R sibirica, R japonica, R helvetica, R honei, R heilongjiangensis, R aeschlimannii, R massiliae, R monacensis; others | Various vertebrates | Distribution varies by species | Bites of ixodid ticks; specific vector varies by species | Similar to other rickettsial diseases, with inoculation site eschar, rash, febrile illness, prevalence of major clinical signs, risk of complications, severity varies |
Typhus group of Rickettsia | |||||
—Murine typhus (fleaborne typhus, endemic typhus) | R typhi | Rats are major reservoir; opossums in some areas; cats, dogs, other species probably involved in peridomestic cycle | Worldwide, especially warmer regions | Infected rodent fleas, usually via flea feces; cat fleas seem to be involved in some cycles | Fever, severe headache, central rash (not always observed); other clinical signs, including arthralgia, cough, nausea/vomiting in some; complications possible in various organs; case fatality rate mortality rate < 1% without treatment |
—Scrub typhus; Chigger-borne rickettsiosis | Orientia tsutsugamushi and related species | Rodents, insectivores | Asia, Australia, islands of southwestern Pacific Ocean; cases are usually concentrated regionally; related organisms may exist in Africa, Middle East, South America | Bite of infected larval trombiculid mites (chiggers) | Nonspecific febrile illness with rash, painful lymphadenopathy, GI signs; eschar in some; complications can include pulmonary disease, neurologic signs, cardiac involvement, jaundice; mild to severe, with estimated case fatality rate from 6% to 30%–50% if untreated |
—Typhus, sylvatic (zoonotic cycle) | R prowazekii | Flying squirrels (Glaucomy s volans) | Eastern US (only human reservoirs known in other locations) | Squirrel lice or fleas suspected | Nonspecific febrile illness, rash; GI signs in some; sepsis possible; most cases seem to be milder than non-zoonotic typhus, which has a mortality rate of 10%–60% |
Global Zoonotic Diseases: Fungal Diseases
Disease in Humans | Causative Organism | Animals Involved | Geographic Distribution | Probable Means of Transmission to Humans | Clinical Manifestations in Humans |
|---|---|---|---|---|---|
Blastomyces dermatitidis, B helicus, B percursus, B gilchristii, possibly others | Many mammals including dogs, cats, horses, marine mammals; B helicus might be associated with burrows of small mammals | Distribution in environment uncertain; clinical cases focal; locally acquired cases reported in parts of North America, Africa, Middle East, India; some Blastomyces species can occur in areas where B dermatitidis is not usual | Environmental exposure, eg, moist soil (infection common to humans and animals; also reported rarely by animal exposure (eg, bite from infected pet kinkajou) | Acute to chronic pulmonary disease; skin or bone lesions; meningitis, other syndromes, disseminated disease possible; course mild to severe, some cases fatal | |
Coccidioides immitis, C posadasii | Cattle, sheep, horses, llamas, dogs, many other mammals | Especially southwestern US, Mexico, Central and South America; in arid or semiarid foci; some cases might be acquired outside usual foci | Principally environmental exposure (inhalation of arthrospores), including fungal cultures (infection common to humans and animals), one unusual case reported after postmortem examination of horse with disseminated disease | Self-limited, febrile, flu-like illness, sometimes with cough, chest pain in healthy host; serious, possibly life-threatening pulmonary disease or disseminated infection with cutaneous/subcutaneous lesions, persistent meningitis or osteomyelitis, especially in immunocompromised | |
Cryptococcus neoformansvar grubii, C neoformans var neoformans, C gattii | (Organism from environment grows well in bird or bat guano; temporary colonization of avian intestinal tract also possible); clinical cases in various mammals | Worldwide | Principally environmental exposure, via inhalation or through the skin (infection common to humans and animals), caution warranted around accumulations of bird or bat feces; rare cases associated with pet birds | Respiratory signs, mild to severe, often self-limiting in healthy host but more likely to be severe in immunocompromised; dissemination with CNS disease, ocular signs, other syndromes, most often in immunocompromised; skin lesions, either localized from inoculation (uncommon) or from disseminated disease | |
Histoplasma capsulatum var capsulatum | Organism from environment grows well in bird or bat guano; infections in many domestic and wild mammals including bats and birds | Worldwide; clinical cases often cluster in regional foci | Principally environmental exposure (infection common to humans and animals), caution warranted around concentrations of bat guano (eg, caves) | Flu-like, febrile illness, usually self-limiting in healthy hosts; skin lesions; chronic pulmonary disease, usually with preexisting lung disease; dissemination in very young, elderly, immunocompromised | |
H capsulatum var duboisii | Organism from environment grows well in bird or bat guano; infections in many domestic and wild mammals including bats and birds | Africa | Principally environmental exposure (infection common to humans and animals), caution warranted around concentrations of bat guano (eg, caves) | Usually skin and subcutaneous lesions, osteolytic bone lesions but can disseminate or cause lesions (eg, brain abscess) in other tissues | |
Malassezia infection | Malassezia spp adapted to animals (eg, M pachydermatis) | Dogs, cats, other animals | Worldwide | Exposure to clinically affected animals; normal levels on skin not thought to be an important risk | Dermatitis; zoonotic organisms might be implicated in fungemia, invasive disease in preterm neonates, other immunocompromised |
Ringworm (Dermatophytosis) | Microsporum and Trichophyton spp | Dogs, cats, hedgehogs, cattle, sheep, goats, horses, rodents, other mammals, birds, very rarely reptiles | Worldwide | Direct skin or hair contact with infected animals, fomites | Skin and hair lesions, usually pruritic; rare skin dissemination in immunocompromised |
Sporothrix schenckii complex members, especially S schenckii sensu stricto, S brasiliensis and S globosa | Cats, other mammals, birds, possibly reptiles; cats are more likely to transmit organism to humans than other species | Worldwide; species of Sporothrix may differ in distribution; epizootics in cats in South America | Primarily environmental in vegetation, wood, soil; inoculation from environment in penetrating wounds (eg, splinters, bites, pecks) is most common source, skin contact with lesions, especially in cats also possible; bites, scratches, other close contact implicated during feline epizootics; inhalation rare | Papules, pustules, nodules, ulcerative skin lesions, may follow course of draining lymphatics; mucosa can be affected; extracutaneous involvement, especially bones, joints; disseminated disease (including meningitis) can occur in immunocompromised; acute or chronic pulmonary disease resembling tuberculosis after inhalation, especially with underlying lung disease (rare) | |
Talaromycosis | Talaromyces (Penicillium) marneffei; uncertain zoonotic potential | Organism very common in asymptomatic cotton rats in the genera Rhizomys and Cannomys and their burrows; also found in dogs and other mammals | Asia | Probably acquired from the soil (infection common to humans and animals); most infected humans have no known exposure to bamboo rats; zoonotic potential unclear | Commonly a febrile illness with generalized lymphadenopathy, non-productive cough; often mild in healthy humans; disseminated disease mainly in immunosuppressed, can involve many organs including lung, liver, spleen, lymph nodes, skin, intestinal tract and infrequently CNS; numerous umbilicated or ulcerated skin lesions a common syndrome, often affect the face and neck |
Zoonotic Diseases: Parasitic Diseases
Diseases | Causative Organism | Animals Involved | Geographic Distribution | Probable Means of Transmission to Humans | Clinical Manifestations in Humans |
|---|---|---|---|---|---|
Protozoans | |||||
Babesia microti complex, B duncani (formerly WA-1), and other species | Rodents, insectivores, lagomorphs, some other mammals; reservoirs uncertain for some species | Babesia spp worldwide in wild animals, many agents not identified to species; human illness due to B microti complex reported in North America (most), Europe, Asia, Australia | Bite of infected Ixodes ticks for B microti | Many immunocompetent patients may have mild to moderate flu-like, febrile illness; mild to severe hemolytic anemia, especially severe in immunocompromised and elderly; respiratory, hepatic, renal, and other organ dysfunction; recurrent or chronic infection may develop; dual infection with B burgdorferi may worsen both diseases; death possible in severe cases | |
B divergens | Cattle are major hosts; can also infect reindeer, some sheep; closely related organism (B capreoli) in cervids | Europe, possibly North Africa | Tick bites (Ixodes ricinus) | Usually in splenectomized; acute, onset of severe hemolytic anemia; with persistent high fever, headache, myalgia, abdominal pain, sometimes GI signs; complications of respiratory distress and renal failure common; cases progress rapidly; usually fatal if untreated | |
B venatorum | Cervids are major hosts; also in sheep, probably other mammals | Europe, Asia | Tick bites | Resembles diseases due to other Babesia; noted in both healthy and immunocompromised | |
Balantidiasis | Balantidium coli and related species | Swine, rats, camels, ruminants, equids, nonhuman primates, other animals | Worldwide | Ingestion, especially of water contaminated with feces | Asymptomatic to watery or mucoid, bloody diarrhea; intestinal hemorrhage and perforation possible; rare extraintestinal cases at various sites including urinary tract, liver, lung |
Chagas disease (American trypanosomiasis) | Trypanosoma cruzi | Many wild and domestic mammals including opossums, lagomorphs, rodents, armadillos, dogs, cats | Western hemisphere—southern US, California, Mexico, Central and South America | Fecal material of reduviid bug in family Triatomidae contaminates bite wounds, abrasions, or mucous membranes; ingestion in contaminated food; congenital infections possible and can lead to disease, often later in life | Acute disease—erratic fever, lymphadenopathy, headache, myalgia, hepatosplenomegaly, swelling at inoculation site and eyelid; myocarditis or encephalitis in some; worse in immunocompromised; chronic form (in 10%–30% of patients)—cardiomyopathy, megaesophagus, megacolon, other forms; cardiac disease is associated with most deaths |
Cryptosporidium parvum, occasionally C canis, C felis, C meleagridis, C cuniculus, C andersoni, C suis, C viatorum, C muris, and other species (C hominis and some C parvum are maintained in humans) | Cattle and other ruminants, dogs, cats, rabbits, other domestic and wild mammals, birds, reptiles, fish | Worldwide | Fecal-oral; ingestion of contaminated food and water; inhalation | Self-limiting gastroenteritis in healthy; can be cholera-like and persistent in immunocompromised, with weight loss, wasting; cholecystitis; respiratory signs, pancreatitis, other syndromes mainly in immunosuppressed | |
Giardia intestinalis, also known as G duodenalis (formerly G lamblia); only some genotypes seem to have zoonotic potential | Many domestic and wild mammals, including dogs, cats, ruminants, aquatic mammals (eg, beavers) | Worldwide | Ingestion of water and less often food; direct fecal-oral (hands or fomites) | Gastroenteritis, may be persistent | |
—Visceral (Kala-azar) | Leishmania infantum | Wild canids and dogs are primary reservoirs, also in other mammals | South America, parts of Asia, the Middle East, Europe (mainly Mediterranean), North America (foxhound associated in this location) | Mainly bite of sand flies Phlebotomus and Lutzomyia spp, but also uncommon minor routes (eg, blood transfusion, transplacental, venereal) | Undulating fever, hepatosplenomegaly, nonspecific clinical signs (weight loss, malaise); some have other clinical signs such as cough, chronic diarrhea, lymphadenopathy, thrombocytopenia associated with petechiae or hemorrhages on mucous membranes, skin lesions, clinical signs of chronic kidney disease; pancytopenia; mild cases with only a few clinical signs (eg, localized lymphadenopathy) may resolve on their own; however, most other cases fatal if untreated |
—Cutaneous and mucocutaneous | L tropica complex (except L tropica, which is maintained in humans), L braziliensis complex, L mexicana complex, others | Diverse mammals and marsupials, primarily among wildlife, are reservoirs for the various species of Leishmania; other animals including domestic species can be infected;L peruviana has been detected in dogs but their relevance as a maintenance host uncertain | Leishmania occur on all major continents but distribution varies with the species and may be focal (most cases in Europe occur in the Mediterranean); North American infections are mainly associated with a localized focus of L mexicana in Texas and Oklahoma) | As above | Papules to ulcers or nodules on skin ± mucous membranes; single or multiple lesions; localized or disseminated; may persist or recur; atypical forms, especially in immunosuppressed; cutaneous form rarely fatal, mucocutaneous form can be disfiguring and may be fatal if pharynx affected |
Malaria of nonhuman primates | P knowlesi, P cynomolgi, P simium, P brasilianum , others | Old and New World monkeys, apes | Southeast Asia, South America, Africa | Bite of anopheline mosquitoes | Febrile episodes with chills; headache, myalgia, malaise, cough, nausea, vomiting, and other symptoms in some; cases range from mild, self-limiting to fatal (3% case fatality rate for P knowlesi) |
Microsporidiosis | Microsporidia of Enterocytozoon bieneusi, Encephalitozoon cuniculi, E intestinalis, E hellem, others; zoonotic importance may depend on genotype | Widespread in vertebrates, including primates, rabbits, rodents, dogs, cats, cattle, pigs, goats, birds, fish; also in invertebrates | Worldwide | Fecal-oral; direct contact; ingestion of contaminated food or water; aerosols; possibly vector-transmitted | Keratitis; acute diarrhea (traveler’s diarrhea); chronic diarrhea in immunocompromised; may disseminate to systemic disease with variable symptoms in immunocompromised |
Rhinosporidium seeberi; some strains may be host specific | Natural hosts thought to be fish and aquatic amphibians; various mammals and birds can be incidental hosts | Subtropical and tropical regions in South America, Asia, and Africa | Environmental exposure via water, especially stagnant water | Nasal and other mucous membrane masses and polyps (mainly nose, nasopharynx, eye); may cause obstruction; rare disseminated disease with osteolytic lesions or affecting viscera; rare skin and subcutaneous lesions | |
Sarcocystosis (Sarcosporidiosis) | Sarcocystis suihominis, S hominis, S heydorni | Humans are definitive hosts; swine are intermediate hosts for S suihominis; cattle are intermediate hosts for S hominis, S heydorni | Worldwide | Ingestion of parasites (sarcocysts) in raw tissues of intermediate host | Gastroenteritis, usually mild, or asymptomatic |
Sarcocystis spp;a number of cases have been associated withS nesbitti | Humans are intermediate hosts for Sarcocystis spp, parasite often not identified to the species level; definitive host for S nesbitti thought to be snakes | Worldwide; most symptomatic cases are associated with S nesbitti and occur in Southeast Asia, especially Malaysia | Ingestion of oocysts or sporocysts shed in feces of definitive hosts, often in contaminated food or water | Main syndrome is myositis, which often ends in weeks to a few months, but may persist longer; some have nonspecific prodromal syndrome with fever, malaise, cough, arthralgia; transient pruritic rashes possible | |
Toxoplasma gondii | Felidae, including domestic cats, are definitive hosts; essentially all other mammals (including production animals) and birds thought to be susceptible as intermediate hosts | Worldwide | Ingestion of oocysts shed in feces of infected cats (including contaminated soil, food, water) or ingestion of tissue cysts in undercooked meat or unpasteurized milk | Lymphadenopathy or mild, febrile flu-like syndrome or ocular disease in immunocompetent, nonpregnant host, serious disease possible but uncommon; often severe in immunocompromised, with neurologic disease, chorioretinitis, myocarditis, pneumonitis, or disseminated disease; infection of fetus may result in CNS damage or generalized infection; abortions and stillbirths | |
Trypanosomiasis (African sleeping sickness) | T brucei rhodesiense; | Cattle, other domestic and wild animals are reservoirs | Sub-Saharan Africa | Bite of infected tsetse fly (Glossina spp) | Painful chancre at bite site in some patients; intermittent fever, headache, adenopathy, rash, arthralgia; neurologic signs; cardiac complications possible; usually fatal without treatment |
Trematodes (Flukes) | |||||
Clonorchiasis | Clonorchis sinensis (Chinese liver fluke) | Humans and carnivorous mammals are definitive hosts; snails and freshwater fish or shrimp are 1st and 2nd intermediate hosts | Asia | Ingestion of undercooked infected freshwater fish or shrimp containing encysted larvae | Nonspecific clinical signs, jaundice, hepatosplenomegaly,indigestion, chronic infections associated with cirrhosis, pancreatitis, or cholangiocarcinoma |
Dicrocoeliasis | Dicrocoelium dendriticum, possibly other species (eg, D hospes) | Ruminants, especially sheep, goats, cattle, occasionally other domestic and wild mammals are definitive hosts; land snails (first) and ants (second) are intermediate hosts | D dendriticum on all major continents (may be focal); D hospes in sub-Saharan Africa | Ingestion of infected ants | Abdominal discomfort, flatulent indigestion; occasionally GI signs (diarrhea, constipation, vomiting, pain); weight loss, fatigue; biliary obstruction, cholangitis, hepatomegaly, or acute urticaria possible |
Echinostomiasis | Echinostoma revolutum, E ilocanum, E hortense, and other Echinostoma spp; Echinochasmus japonicus and other members of Echinostomatidae | Cats, dogs, rodents, pigs, other mammals; birds, including poultry, are definitive hosts; fish, shellfish, tadpoles, snails are intermediate hosts | Widely distributed, including Asia, Europe, Americas, Middle East, but most cases in humans reported in Asia, Western Pacific | Ingestion of undercooked fish, shellfish, snails, or amphibians (frogs) | Often subclinical; Abdominal discomfort; GI signs, especially in heavy infestation; malnutrition, may occur, especially in children |
Fascioliasis | Fasciola hepatica | Cattle, sheep, water buffalo, horses, rabbits, other herbivores are definitive hosts; snails are intermediate hosts | Worldwide or nearly worldwide; previously thought to be mainly in temperate areas but may be more widely distributed | Ingestion of contaminated greens, eg, watercress, or water that contains metacercariae | Gastroenteritis, hepatomegaly, fever, urticaria possibly acutely; biliary colic and obstructive jaundice in chronic cases; aberrant migration with extrahepatic signs possible |
F gigantica | Cattle, buffalo, goats, sheep, zebras, other mammals are definitive hosts; snails are intermediate hosts | Thought to occur mainly in tropical and subtropical regions of Africa, Asia, Middle East, and western Pacific | As above | Clinical signs resemble fascioliasis due to F hepatica | |
Fasciolopsiasis | Fasciolopsis buski | Swine, humans are definitive hosts; snails are intermediate hosts | Asian pig-raising regions | Ingestion of aquatic vegetables or contaminated drinking water containing metacercariae | Often asymptomatic; gastroenteritis; intestinal bleeding, obstruction, or perforation possible; facial, abdominal, extremity edema may occur; heavy infection can be fatal |
Gastrodiscoidiasis | Gastrodiscoides hominis; uncertain whether humans and swine carry the same strains | Swine, humans, nonhuman primates, rodents, other mammals are definitive hosts; snails are intermediate hosts | Asia, possibly other locations | Possibly ingestion of water or aquatic plants | Mild diarrhea if high parasite burden |
Infection with heterophyid trematodes (Heterophyiasis, metagonimiasis) | Heterophyes spp, Haplorchis spp, Metagonimus spp, Centrocestus spp and other heterophyids | Diverse fish-eating mammals, birds are definitive hosts (host varies with species of parasite); fish (and snails) are intermediate hosts | Middle East (especially Nile delta), Turkey, Asia | Ingestion of undercooked fish containing encysted larvae, including accidental ingestion while preparing food | Diarrhea with mucus, colicky pain; involvement of extraintestinal sites (eg, heart or CNS) possible; severity of clinical signs may vary with species |
Metorchiasis | Metorchis conjunctus (Canadian liver fluke) and other Metorchis spp | Various fish-eating domestic and wild mammals; birds are definitive hosts; fish (and snails) are intermediate hosts | M conjunctus in North America; other species in Asia, Europe | Ingestion of undercooked freshwater fish containing encysted larvae | Fever, abdominal pain (mainly epigastric), anorexia during acute stage; effects of chronic infection uncertain; asymptomatic infections common |
Nanophyetiasis | Nanophyetus salmincola and other Nanophyetus spp | Various domestic and wild fish-eating mammals and birds are definitive hosts; salmonid and some non-salmonid fish (and snails) are intermediate hosts | North America and Eurasia along Pacific coast | Ingestion of undercooked fish or roe | Mild gastroenteritis |
Opisthorchiasis | Opisthorchis felineus (cat liver fluke), O viverrini (small liver fluke) | Various fish-eating mammals including cats, dogs, pigs, wildlife, humans are definitive hosts; fish (and snails) are intermediate hosts | O felineus in Europe, Kazakhstan, Russia, Ukraine; O viverrini in Southeast Asia | Ingestion of undercooked freshwater fish containing encysted larvae | Initially asymptomatic or upper abdominal pain, GI signs, jaundice; acute febrile illness with arthralgia, lymphadenopathy, skin rash also reported; suppurative cholangitis and liver abscess in subacute, chronic stages; possible increased risk of cholangiocarcinoma |
Amphimerus spp | Various mammals, birds, reptiles are definitive hosts; fish are intermediate hosts | North and South America (clinical cases mainly Ecuador); sporadic reports of Amphimerus spp in eastern hemisphere | Ingestion of undercooked fish | Asymptomatic or nonspecific clinical signs; possibly chronic effects similar to other liver flukes | |
Paragonimiasis (Lung fluke disease) | Paragonimus westermani, P kellicotti, and other species | Dogs, cats, swine, wild carnivores, opossums, and other mammals are definitive hosts; snails and freshwater crustaceans are intermediate hosts; wild boars, sheep, goats, rabbits, birds, other animals are paratenic hosts | Flukes are worldwide (distribution varies with species); most human infections in Asia, Africa, tropical America | Ingestion of undercooked, infected freshwater crustaceans (crabs, crayfish); metacercariae on contaminated hands, fomites after preparing crustaceans, or undercooked meat from paratenic hosts (eg, wild boars) | Chills, fever possible during migration to lungs; pulmonary disease resembling tuberculosis with cough, blood-tinged sputum; abdominal form with dull pain, tenderness, possibly diarrhea; less often, neurologic signs, migratory skin nodules, other organ-specific symptoms; predominant clinical signs vary with species of fluke |
Schistosomiasis, intestinal and hepatic | Schistosoma japonicum | Many wild and domestic mammals, including cattle, water buffalo, swine, dogs, cats, horses, and rodents are definitive hosts; snails are intermediate hosts | Asia | Penetration of unbroken skin by cercariae from infected snails in water | Acute disease in some with symptoms that may include fever, urticarial rash, nonspecific clinical signs, cough, hepatosplenomegaly, GI signs, apparent clinical recovery may be followed by chronic intestinal schistosomiasis with abdominal pain/discomfort, diarrhea ± blood; may induce inflammatory polyps in colon; chronic hepatic schistosomiasis with liver fibrosis, ascites, portal hypertension ectopic parasites can affect CNS; some cases fatal |
S mattheei; S bovis and S margrebowiei might also be zoonotic | Definitive hosts are artiodactylid ruminants (cattle, sheep, goats, waterbuck, wildebeest, antelope, buffalo), also found in nonhuman primates; snails are intermediate hosts | Southern Africa; seems to be rare in humans, and some infections may have been misidentified | Penetration of unbroken skin by cercariae from infected snails in water | Suggested agent in intestinal and hepatic schistosomiasis | |
Swimmer’s itch (Cercarial dermatitis) | Schistosome cercariae from Schistosoma spp (mammals); Gigantobilharzia, Trichobilharzia, and Austrobilharzia spp (birds) | Birds, mammals are definitive hosts; snails are intermediate hosts | Worldwide | Penetration of unbroken skin by cercariae from infected snails in fresh- and saltwater | Self-limiting urticaria, pruritus, rash; fever, local lymph node swelling possible in some cases |
Cestodes (Tapeworms) | |||||
Bertielliasis | Bertiella studeri, B mucronata | Nonhuman primates are usual hosts; other mammals, including dogs, humans can be infected | Asia, South America, Africa; can occur in imported primates in other areas | Ingestion of infected oribatid mites in food | Most cases asymptomatic; abdominal pain, vomiting, diarrhea, constipation, weight loss |
Coenuriasis (Coenurosis) | Taenia multiceps | Definitive hosts are canids; intermediate hosts are sheep, goats, other domestic and wild herbivores or omnivores, occasionally including humans; both domestic and sylvatic cycles exist | Appears cosmopolitan in scattered foci; however, domestic animal cycle no longer reported from some countries including US | Ingestion of eggs shed by canids in feces, may be via water, vegetables, soil | Various tissues but clinical cases most often reported in subcutaneous tissues, CNS, eye; large numbers of cysts in muscles can be symptomatic |
T serialis (see also Taeniasis) | Definitive hosts are canids, primarily foxes; intermediate hosts are lagomorphs, infrequently rodents, occasionally other mammals including humans | Africa, Europe, North America, parts of Asia, Middle East, Australia, probably others | As above | As above | |
T brauni (T serialis brauni) | Definitive hosts are canids; intermediate hosts are wild rodents, occasionally other species including humans | Africa | As above | As above | |
Cysticercosis | Taenia solium | Definitive hosts are humans; Intermediate hosts are domestic and wild pigs, occasionally other mammals including humans | Cycle can be perpetuated where swine are reared and have access to human feces; most cases occur rural areas with poor sanitation in Africa, Asia, Central and South America; sporadic cases in developed countries including the US especially in foci where human carriers transmit eggs to other humans | Ingestion of eggs (including autoinfection from eggs shed by adult parasite in human intestine), may be in water, vegetables (or other food contaminated by human carriers), soil | Various tissues but clinical cases most often reported in subcutaneous tissues, CNS, eye; large numbers of cysts in muscles can be symptomatic. Disseminated cases affecting multiple organs are uncommon but can occur |
T crassiceps, T martis,Hydatigera (Taenia) taeniaeformis, Versteria (Taenia) mustelae, probably others | Definitive hosts are carnivores and omnivores: T crassiceps mainly in canids, especially foxes; H taeniaformis most often in cats and other felids; T martis, V mustelae primarily in mustelids. Intermediate hosts for T crassiceps, H taenniaeformis, T martis, and V musteale are usually rodents and other small mammals; however, they occasionally infect other species including humans | Varies with the species. H taeniaformis is cosmopolitan; T crassiceps, T martis, and V mustelae occur in northern temperate zones (North America, Europe, Asia) | Ingestion of eggs shed in feces of definitive host, may be in water, vegetables, soil | As above. Most species form a single cysticercus from each larva but T crassiceps proliferates and can form large masses and spread to other sites | |
Diphyllobothriasis (Fish tapeworm infection) | Diphyllobothrium latum (Dibothriocephalus latus), D nihonkaiense, D pacificum, D dendriticum, and other Diphyllobothrium spp | Dogs, bears, seals, sea lions, gulls, and other fish-eating mammals and birds are definitive hosts; freshwater or marine fish (and copepods) are intermediate hosts | Worldwide; distribution of species varies | Ingestion of undercooked infected fish | Usually asymptomatic; may cause mild abdominal distress, diarrhea (chronic relapsing diarrhea possible in some cases) |
Dipylidiasis (Dog tapeworm infection) | Dipylidium caninum | Dogs, cats, wild canids, some other wild carnivores are definitive hosts; fleas are intermediate hosts | Worldwide; uncommonly reported in humans | Ingestion of dog or cat fleas | Usually in children; asymptomatic or mild abdominal distress, diarrhea; proglottids in feces resemble cucumber seeds |
Echinococcosis (hydatid disease) | Echinococcus granulosus sensu lato complex: E granulosus sensu stricto, E canadensis, E ortleppiare known to be zoonotic | Dogs and other canids, hyaenids, occasionally felids are definitive hosts; sheep, goats, cattle, water buffalo, swine, camelids, equids, cervids, rodents, other mammals or marsupials are intermediate or aberrant hosts; Host specificity differs between species of Echinococcus | Worldwide, species differ in distribution | Ingestion of tapeworm eggs in food or water, to mouth on hands; eggs stick to fur and hands | Cause space-occupying lesions of organs, especially lung, liver, also other organs, rarely CNS; cyst grows slowly, can cause death if untreated; rupture can cause allergic reactions, dissemination of cysts |
E multilocularis | Foxes and other wild canids and felids are usual definitive hosts; however, parasite can also mature in dogs, cats (cats mostly thought to play only minor role); intermediate hosts are usually rodents and other small mammals | North America (mainly Canada to north central US), northern and central Eurasia | Ingestion of tapeworm eggs in food or water, to mouth on hands; eggs stick to fur and hands | Primary lesion usually in liver; primary lesion can metastasize to many organs; 90%–100% cases are fatal without treatment | |
E oligarthrus (= E oligartha) | Wild felids are definitive hosts, can mature in cats; agouti, pacas, spiny rats are intermediate hosts | Central and South America; rare in humans | Ingestion of tapeworm eggs in food or water, to mouth on hands; eggs stick to fur and hands | Likely to affect internal organs, can occur in periorbital tissues | |
E vogeli | Bush dogs (Speothos venaticus) are usual definitive host, can mature in other canids, including dogs; pacas, agouti, nutria, nonhuman primates, and other mammals can be intermediate hosts | Central and South America | Ingestion of tapeworm eggs in food or water, to mouth on hands; eggs stick to fur and hands | Primary lesion usually involves liver, can spread to other sites; mortality high without treatment | |
Hymenolepiasis | Hymenolepis nana (dwarf tapeworm); most human infections probably transmitted from humans, but zoonoses possible | Humans, nonhuman primates, rodents are definitive hosts; insects, including fleas, flour beetles, cereal beetles are intermediate hosts | Worldwide | Accidental ingestion of tapeworm eggs or infected insects; autoinfection possible | Mainly in children; mild abdominal distress, decreased appetite, irritability are most common; weight loss, flatulence, diarrhea possible |
H diminuta (mouse tapeworm, rat tapeworm) | Rats, mice are definitive hosts; insects, including fleas and cereal beetles are intermediate hosts | Worldwide | Ingestion of infected insects in food | Mild abdominal symptoms of short duration | |
Inermicapsifer infection | Inermicapsifer spp | Rodents, humans are definitive hosts in Africa; humans may be exclusive host outside Africa | Africa, southeast Asia, tropical America | Probably ingestion of infected arthropods | Mild abdominal symptoms, if any |
Mesocestoides infection | Mesocestoides lineatus, M variabilis | Wild and domestic carnivorous mammals (canids, felids, procyonids, mustelids, others) are definitive hosts; Various mammals, birds, reptiles, amphibians are intermediate hosts; possibly 2nd invertebrate intermediate host | Possibly cosmopolitan but most clinical cases from Asia, North America | Uncertain | Asymptomatic cases probably most common; GI signs in some; motile proglottids observed |
Raillietina infection | R celebensis, R demerariensis; most Raillietina spp have not been reported in humans | Rodents, nonhuman primates are definitive hosts for R celebensis, R demerariensis; other species in birds, mammals; arthropods, including ants, are intermediate hosts | R demerariensis in tropical America (human cases mainly Ecuador, Cuba, Guyana, Honduras); R celebensis in Asia, Australia, Africa | Probably ingestion of infected arthropods in food | Vague discomfort, many cases asymptomatic; gastroenteritis, possibly other signs; mainly in children |
Sparganosis | Spirometra spp (pseudophyllidean tapeworms, second larval stage) | Dogs, cats, wild canids and felids are definitive hosts; copepods are first intermediate host; fish, frogs, reptiles are second intermediate hosts; primates, pigs, weasels, rodents, insectivores, other mammals, birds are paratenic hosts | Worldwide; human cases most common in Asia | Ingestion of infected cyclops (in water) or undercooked intermediate or paratenic host; application of contaminated tissues to skin (eg, as poultice) | Nodular, itchy skin lesions that can migrate; conjunctival and eyelid lesions; urticaria, painful edema; other organ involvement, including CNS, eye |
Taeniasis | |||||
—Asian taeniasis | Taenia asiatica | Definitive hosts are humans; Intermediate hosts are pigs and wild suids; cattle, goats and nonhuman primates were infected experimentally as intermediate hosts | Asia | Ingestion of mature cysticerci (larvae) in undercooked animal products, usually visceral organs, especially liver; however, some cysts have been found in muscle | Proglottid passage in feces but otherwise asymptomatic in many cases. Mild abdominal complaints (eg, discomfort, intermittent diarrhea, nausea, changes in appetite) in some. Rarely more serious syndromes, eg, obstruction or tapeworms at aberrant sites |
—Beef tapeworm disease | T saginata | Definitive hosts are humans; intermediate hosts include cattle, water buffalo, reindeer, and other domestic and wild ungulates. Most species other than cattle have insignificant role in perpetuating cycle but reindeer play a role in northern Russia | Worldwide but typically uncommon in developed countries | Ingestion of mature cysticerci (larvae) in undercooked tissues, usually skeletal muscle (meat) | Proglottid passage in feces but otherwise asymptomatic in many cases. Mild abdominal complaints (eg, discomfort, intermittent diarrhea, nausea, changes in appetite) in some. Rarely more serious syndromes, eg, obstruction or tapeworms at aberrant sites T saginata proglottids are motile and can also migrate through anus, causing anal pruritus, and may occasionally travel to ectopic sites (eg, bile ducts, appendix) and cause symptoms |
—Pork tapeworm disease (see alsocysticercosis) | T solium | Definitive hosts are humans; Intermediate hosts are pigs and wild suids, occasionally other mammals including humans | Cycle can be perpetuated where swine are reared and have access to human feces; most cases occur in rural areas with poor sanitation in Africa, Asia, Central and South America; sporadic cases in developed countries including the US especially in foci where human carriers transmit eggs to other humans | Ingestion of mature cysticerci (larvae) in undercooked tissues, usually skeletal muscle (meat). Eggs shed by tapeworm carrier can be ingested by host or other humans, causing cysticercosis | Proglottid passage in feces but otherwise asymptomatic in many cases. Mild abdominal complaints (eg, discomfort, intermittent diarrhea, nausea, changes in appetite) in some. Rarely more serious syndromes, eg, obstruction or tapeworms at aberrant sites. Some humans have concurrent cysticercosis. |
Nematodes (Roundworms) | |||||
Angiostrongyliasis | Angiostrongylus costaricensis, also called Parastrongylus costaricensis | Rodents are definitive hosts; patent infections reported occasionally in other mammals including dogs; slugs are intermediate hosts | Mainly in Central and South America, Caribbean parasite has also been reported in North America | Accidental ingestion of slugs or possibly plants contaminated by their secretions | Acute abdominal angiostrongyliasis; severe pain resembles appendicitis, especially in children; rarely, more insidious disease with liver involvement; complications can include intestinal ischemia, perforation; fatalities possible |
Angiostrongylus cantonensis, also called Parastrongylus cantonensis | Rodents are definitive hosts; snails, slugs are intermediate hosts; land planarians, crustaceans (crabs, shrimp, prawns), amphibians, fish, reptiles are paratenic hosts | Originated in Asia, spread to many other geographic areas, mainly tropics, including Americas, Caribbean, Middle East, Australia | Ingestion of raw or undercooked intermediate or paratenic host (or accidental ingestion on vegetables); possibly ingestion of plants contaminated by secretions of intermediate host | Eosinophilic meningitis or meningoencephalitis, spinal cord involvement; ocular involvement with decreased vision; transient abdominal pain, pruritus in some; most cases relatively mild and self-limiting, but some fatal | |
Anisakiasis | Anisakis, Pseudoterranova, and Contracaecum spp | Marine mammals (cetaceans and pinnipeds) and fish-eating birds are definitive hosts; fish, crustaceans, and cephalopod mollusks are intermediate or paratenic hosts | Worldwide but many cases in northern Asia and western Europe | Ingestion of undercooked marine fish, squid, octopus | Gastroenteritis with upper quadrant pain; parasite usually in stomach; small-intestinal infections unusual but can occur; colon, esophagus rarely involved; oropharyngeal location (uncommon) can cause hematemesis, cough; urticaria and other allergic signs after ingestion of live or dead worms |
Ascariasis | Ascaris suum | Pigs, also reported occasionally in other mammals, including nonhuman primates, sheep, cattle | Worldwide, prevalence varies | Ingestion of eggs from environment (shed in feces) | Visceral larva migrans (respiratory signs, fever during larval migration); GI signs |
Capillariasis | |||||
—Hepatic capillariasis | Capillaria hepatica (also called Calodium hepaticum) | Rodents major host, also in many other wild and domestic mammals | Worldwide in scattered foci | Ingestion of embryonated eggs in soil; possibly eating contaminated undercooked tissues from infected animals | Acute or subacute hepatitis with marked eosinophilia; fever, diarrhea, respiratory signs also common; subclinical to fatal |
—Intestinal capillariasis | C philippinensis (also called Paracapillaria philippinensis) | Aquatic birds, humans can be definitive hosts; freshwater fish are intermediate host | Philippines, Thailand, also reported occasionally in other parts of Asia, Middle East, Cuba | Ingestion of undercooked infected fish | Enteropathy with protein loss and malabsorption; diarrhea, abdominal pain; weight loss can be severe; death possible |
—Pulmonary capillariasis | C aerophila (also called Eucoleus aerophilus) | Dogs, cats, other canids and felids, other carnivores (eg, mustelids) | Worldwide; rare in humans | Accidental ingestion of infective eggs in soil or contaminated food | Fever, cough, bronchospasm, bronchitis, dyspnea; can mimic bronchial carcinoma |
Dioctophymosis (Dioctophymiasis) (Giant kidney worm infection) | Dioctophyme (= Dioctophma) renale | Mink, dogs, cats, and other carnivores are definitive hosts; annelids are intermediate hosts; frogs, fish are paratenic hosts | Worldwide; rare in humans | Ingestion of infected fish, frog, or annelid | Renal colic, hematuria, pyuria, ureteral obstruction, various kidney complications can be fatal; aberrant locations include subcutaneous nodules, retroperitoneal |
Dracunculiasis (Guinea worm infection) | Dracunculus medinensis; humans are most important host | Humans, nonhuman primates are definitive hosts; infections have also been reported in other animals; dogs appear to be reservoir hosts in some locations; copepods are intermediate hosts | Asia (mainly Indian subcontinent) and Africa | Ingestion of infected cyclops in water | No symptoms until just before larviposition (~1 year); papule to vesicular skin lesion to ulcer that opens in water to reveal worm; allergic reaction common at this time, and secondary infection may occur |
Filariasis | |||||
—Dirofilariasis | Dirofilaria immitis | Dogs, cats, other mammals especially carnivores, mustelids; (mainly patent in dogs and wild canids; accidental hosts include primates (eg, humans, lemurs, pinnipeds) | Worldwide | Bite of infected mosquitoes | Fever, cough acutely, larvae result in infarct or coin lesion in the lungs; often asymptomatic; rarely involves eye or other body sites |
D repens, occasionally other species (eg, D tenuis, Dursi, D striata) | D repens mainly patent in dogs and some wild canids (eg, foxes); also felids (not usually patent), mustelids | Worldwide, distribution varies with the organism | Bite of infected mosquitoes | Subcutaneous nodule or submucosal swelling, some migratory or painful; subconjunctival (rarely intraocular); internal location (mainly lung but also brain, other organs) possible | |
—Malayan filariasis | Brugia malayi; subperiodic form is of uncertain origin, thought to be zoonotic or maintained in both animals and humans; periodic form is exclusive to humans | Cats, wild felids, pangolins, other carnivores, nonhuman primates susceptible | Asia; subperiodic form limited to peninsular Malaysia, Thailand, and parts of Indonesia, Vietnam, and the Philippines in swamp-forest environments | Bite of infected mosquitoes, Mansonia spp mainly associated with subperiodic form | Lymphatic filariasis: recurrent painful lymphadenitis, lymphangitis, often preceded by prodromal illness with malaise or urticaria; may progress to elephantiasis, usually of legs; hypersensitivity syndrome with cough, chest pain, asthmatic attacks especially at night |
Filariasis due to other Brugia species | Brugia spp other than B malayi, including B pahangi | Various domestic and wild mammals, including dogs and cats, are definitive hosts | Asia, Africa, Americas | Mosquitoes | Occasional zoonotic infections (eg, cutaneous nodules, granuloma in lymph nodes, conjunctival) |
Gnathostomiasis | Gnathostoma spinigerum, G binucleatum, and some other Gnathostoma spp | Dogs, cats, wild carnivores are definitive hosts (G doloresi and G hispidum in pigs and wild boars); copepods, freshwater fish, eels, frogs, snakes, chickens, snails, pigs are intermediate or paratenic hosts | Worldwide; human cases; most common in areas where dietary risk factors common | Ingestion of undercooked fish, poultry, or other intermediate or paratenic host, drinking water contaminated with copepods containing larvae; handling meat that contains larvae | Fever, malaise, gastroenteritis, urticaria, soon after ingestion; migratory skin lesions (intermittent swelling, often painful or pruritic, or linear erythematous lesions) after weeks to years; may involve viscera, eye, or CNS; CNS involvement can be fatal or result in permanent damage with reported case fatality rates of 7%–25% |
Gongylonemiasis | Gongylonema pulchrum, possibly G nepalensis | Ruminants, domestic and wild swine, other mammals, birds are definitive hosts for Gongylonema spp; coprophagous insects (eg, beetles, cockroaches) are intermediate hosts; paratenic hosts might exist | Worldwide; rare in humans | Ingestion of infected beetles, probably on vegetables; possible inhalation of small beetles | Movement of parasite in submucosa of mouth is sensed; local irritation in oral cavity, esophagus, and pharynx; parasite in other locations (eg, eye) possible |
Larva migrans, cutaneous (see also gnathostomiasis) | Ancylostoma braziliense, A caninum, A ceylanicum, Uncinaria stenocephala | Cats, dogs, wild carnivores are definitive hosts | Worldwide; distribution varies with the species | Contact with infective larvae that penetrate skin, usually via soil | Itchy, serpiginous, migrating skin lesions; papules, nonspecific dermatitis, vesicles; wheezing, cough, and urticaria may occur; myositis or ocular lesions possible; eosinophilic enteritis after ingestion of A caninum; A ceylanicum can also become patent in intestine, causing GI signs, anemia |
Bunostomum phlebotomum | Cattle | Temperate areas | As above | As above | |
Strongyloides stercoralis strains adapted to dogs and other Strongyloides spp found in animals | S stercoralis in dogs, cats, primates | Worldwide, more common in tropics and subtropics | Contact with infective larvae that penetrate skin, from soil or direct contact with feces; autoinfection possible with S stercoralis | Larva currens (linear, serpiginous urticarial inflammation, often rapidly progressive); S stercoralis may also mature in intestine, causing enteritis and other signs | |
Larva migrans, visceral (see also angiostrongyliasis and anisakiasis) | Toxocara canis, T cati, possibly others | Dogs and wild canids (T canis), cats and wild felids (T cati) are definitive hosts; many species can be paratenic hosts | Worldwide | Ingestion of embryonated eggs shed in feces of dogs and cats; via soil, water, food, fomites | Fever, wheezing cough, upper abdominal discomfort; other symptoms, including neurologic signs, skin rashes also possible; may wax and wane for months; eye involvement (ocular migrans) may resemble retinoblastoma |
Baylisascaris procyonis, possibly other species of Bayliscascaris | Raccoons, kinkajous are definitive hosts; dogs can be definitive or intermediate host; many mammals (including humans), marsupials, and birds are intermediate or paratenic hosts | North America, Europe, Japan | Accidental ingestion of embryonated eggs in soil, water, or fecal-contaminated material | Nonspecific clinical signs, including fever, lethargy; hepatomegaly, pneumonitis, parasitic meningoencephalitis (may be fatal in infants, young children), ocular disease; other syndromes, including cardiac disease | |
Oesophagostomiasis, Ternidensiasis | Oesophagostomum spp, Ternidens deminutus; zoonotic potential may vary with parasite species or strain and geographic area | Primates, including humans | Parasites found in Africa, Asia, South America; human cases mainly reported in Africa | Ingestion of infective larvae in soil, often in food or water | Abdominal pain and one or more masses ± mild fever; intestinal obstruction or abscessation possible; multinodular form (less common) with abdominal pain, persistent diarrhea, weight loss; rarely ectopic in omentum, liver, or skin |
Onchocercosis (Onchocerciasis) | Onchocerca gutturosa, O cervicalis, O jakutensis, O dewittei japonica, O reticulata, O lupi, others | Definitive hosts include various ungulates including cattle, horses, cervids, dogs and other canids | Distribution varies with species; some organisms (eg, O lupi widespread) | Probably transmitted by black flies (Diptera: Simuliidae), possibly other vectors | Ocular disease, subcutaneous nodules |
Strongyloidiasis | Strongyloides stercoralis; most human infections thought to be from strains adapted to humans; frequency of maturation of canine S stercoralis in humans undetermined, thought to be rare | S stercoralis in dogs, cats, foxes, primates, including humans | S stercoralis worldwide; more common in tropical and subtropical climates | Contact with infective larvae that penetrate skin, in soil or direct contact with feces; autoinfection possible | Frequently asymptomatic in healthy; possible larva currens; respiratory signs in some (cough to bronchopneumonia), especially in elderly, immunocompromised; abdominal pain, diarrhea, sometimes with periodic urticarial or maculopapular rash; disseminated strongyloidiasis, neurologic complications, septicemia, and death may occur in immunocompromised |
S fuelleborni | Primates, including humans | Africa, Asia, and in captive primates in other areas | As above | Associated with abdominal pain, occasional diarrhea, not well studied | |
Thelaziasis (Eyeworms) | Thelazia callipaedia, T californiensis, possibly other species | Definitive hosts are dogs and other canids, cats, wild mammals; flies are intermediate hosts | T callipaedia in Asia, Europe, possibly other locations; T californiensis in North America (western US); rarely in humans | Flies release parasite larvae on conjunctiva | Conjunctivitis; corneal scarring, opacity in chronic cases |
Trichinosis (Trichinellosis) | Trichinella spiralisT nativa, T britovi, T nelsoni, T pseudospiralis, others | Main reservoir may be wild carnivores (foxes, badgers, wolves, lynx), omnivores (bears, boars); also in any mammal that eats (or is fed) meat, including domestic swine, rodents, cats, dogs, horses, marine mammals; also birds (T pseudospiralis); T zimbabwensis (zoonotic potential unknown) can infect reptiles | Worldwide, especially in temperate areas; some species are limited in their distribution | Ingestion of undercooked pork, horse meat, game, and other tissues containing viable cysts | Gastroenteritis in some; followed by fever, headache, severe myalgia, facial swelling (especially eyelids); ocular pain, rashes, or pruritus possible; pneumonitis, CNS, or myocardial involvement can occur; inapparent to fatal |
Trichostrongyliasis | Trichostrongylus spp | Cattle, sheep, other domestic and wild ruminants, sometimes other mammals | Worldwide | Ingestion of infective larvae on vegetables or in contaminated water, soil | Asymptomatic or mild gastroenteritis |
Trichuriasis (Whipworm infection) | Trichuris suis, possibly T vulpis and other species; T trichiura (main species in humans) almost always acquired from other humans, zoonotic transmission possible but insignificant | T vulpis in canids; T suis in domestic and wild swine; T trichiura in nonhuman primates | Worldwide, especially warm, humid climates | Ingestion of embryonated eggs on plant foods, water, or in soil | T suis can colonize humans, who develop GI signs; rare larva migrans or intestinal infections suggested from T vulpis (controversial identification) |
Acanthocephalans | |||||
Acanthocephaliasis | Macracanthorhynchus hirudinaceus, Moniliformis moniliformis, Bolbosoma spp, Corynosoma stumosum and other species | Hosts vary with parasite species; definitive hosts include various domestic and wild mammals; intermediate hosts are beetles, cockroaches, crustaceans; fish, reptiles, amphibian can be paratenic hosts | Worldwide | Ingestion of infected beetles, other intermediate hosts, or fish | Gastroenteritis, may lead to gut perforation or intestinal obstruction; some cases asymptomatic |
Annelids (Leeches) | |||||
Hirudiniasis (internal) | Limnatis nilotica and other aquatic leeches | Cattle, buffalo, other domestic and wild mammals, probably frogs | Africa, Asia, southern Europe, Middle East | Drinking unfiltered water (leech enters nares or mouth), wading in deep water (enters genitourinary tract) | Attaches to nasopharynx, pharynx, esophagus, occasionally deeper in respiratory tract, or in genitourinary tract; pressure and/or pain at attachment site; bleeding (eg, hemoptysis, hematemesis, epistaxis, vaginal bleeding), anemia (can be severe); other signs depend on location |
Arthropods | |||||
Acariasis (eg, Mmange) | Mites of Sarcoptes, Cheyletiella, Dermanyssus, and Ornithonyssus spp, Notoedres cati, Trixacarus caviae, Liponyssoides sanguineus; possibly others (uncommon) | Mammals and birds | Worldwide | Contact with infected animals, fomites | Itchy skin lesions |
Myiasis | Cochliomyia hominivorax and Chrysomya bezziana (screwworms) | Mammals; rare in birds | C hominivorax in South America, Caribbean; C bezziana in Asia, Africa, Middle East | Flies lay eggs on host, larvae enter wounds (as small as a tick bite), mucous membranes | Painful, pruritic, foul-smelling, enlarging dermal and subdermal wounds or nodules, often with serosanguineous discharge; some infestations in cavities, including nasal cavity; larvae can invade living tissue, locally destructive (including bone, eye, sinuses, or cranial cavity); can be fatal if untreated |
Cordylobia anthropophaga, rarely C rodhaini (Tumbu flies) | Mammals, often found in dogs, rodents | Africa, Middle East; also reported in Mediterranean region of Europe | Larvae from environment invade unbroken skin | Furuncular swelling at site of invasion, often feet; fever, malaise, focal lymphadenopathy possible | |
Cuterebra spp | Rodents, lagomorphs, occasionally other mammals | North America | Larvae from vegetation enter host in natural cavities or invade intact skin | Subcutaneous furunculoid nodule(s); creeping skin eruption (uncommon); ocular lesions; rarely larvae might be found in upper respiratory tract | |
Dermatobia hominis(human botfly or cattle grub) | Mammals (common in cattle in some regions), some birds | South and Central America, Mexico | Eggs carried by other insects (eg, mosquitoes); larvae hatch and penetrate skin of mammalian host when insect lands | Nonmigratory larvae in furuncles; episodes of pain, intense pruritus, sometimes with lymphangitis or lymphadenitis; can invade eyelids, eye sockets, mouth, especially in children | |
Gasterophilus spp (equine botfly) | Equids, occasionally other mammals | Worldwide | Accidental exposure to larvae | Serpiginous, pruritic red stripes on skin resembling cutaneous larva migrans; very rarely might reach stomach (nausea, vomiting) | |
Hypoderma lineatum, H bovis (warbles), and other Hypoderma spp | H bovis and H lineatum in cattle, sometimes other mammals; other species primarily parasites of deer, caribou, or yaks | North America, Europe, Asia; species distribution varies | Eggs laid on host, larvae invade skin | Usually subcutaneous (slowly moving furuncles that can appear and disappear) or similar to cutaneous larva migrans; endophthalmia uncommon; H lineatum may also cause an eosinophilic syndrome with fever, muscle pain, sometimes respiratory, cardiac, or neurologic signs | |
Oestrus ovis, Rhinoestrus purpureus | O ovis mainly in sheep, goats, also other mammals; R purpureus mainly in equids | O ovis worldwide, usually in warmer climates; R purpureus in Asia, Africa, Europe | Larvae are deposited in nares, conjunctiva, occasionally lips or mouth by adult fly | Conjunctival form, with lacrimation and sensation of irritating foreign body in eye, ocular destruction rare; nasal form with localized pain or pruritus, congestion, headache; also reported in pharynx (inflammation, vomiting, dysphagia), rarely ear; usually self-limiting (except inside eye), because larvae cannot develop beyond first stage in humans | |
Wohlfahrtiamagnifica and other species | Various mammals, some birds | W vigil in North America; W magnifica in Europe (mainly Mediterranean), North Africa, Asia | Larvae deposited on host or nearby, penetrate lesions or intact skin and natural orifices | Subcutaneous abscesses, furuncles; also reported from other sites including eye, genitourinary tract, ear, orotracheal region | |
Pentastomid infections | Armillifer spp (tongue worms) | Definitive hosts are snakes; intermediate hosts are rodents and other small mammals | Probably cosmopolitan; human cases reported in Africa, Asia, Europe, and North America | Ingestion, via water or vegetables contaminated with eggs (from feces or saliva of snakes); undercooked snake meat; contaminated hands, fomites after handling snake meat | Usually asymptomatic; large numbers of parasites can cause multifocal abscesses, masses, or obstruction of ducts in internal organs; symptoms vary with location and may be nonspecific (eg, abdominal pain); ocular localization can result in blindness; death rare |
Linguatula serrata | Definitive hosts are dogs and other canids, possibly felids; intermediate hosts are herbivores (eg, sheep, goats, lagomorphs) and humans | Worldwide | Ingestion of water or vegetables contaminated with eggs (from feces, saliva, or nasal discharge of definitive host); ingestion of larvae in undercooked tissues (usually liver or lymph nodes) from intermediate hosts | Ingestion of eggs is usually asymptomatic but ocular or pulmonary signs, abdominal pain, icterus, and other symptoms possible from larval invasion of internal organs; ingestion of larvae (nasopharyngeal linguatulosis) results in throat irritation, pain, possibly edema, congestion of nasopharynx dyspnea, difficulty swallowing; most severe cases of nasopharyngeal linguatulosis are probably in humans who have been sensitized | |
Tunga infections | Tunga penetrans(sand fleas, jiggers) | Humans, dogs, pigs, other mammals | Africa, Central and South America, Caribbean, south Asia | Skin contact with contaminated soil | Penetration of skin and burrowing result in pain and itching around discrete sores, often on feet; may be secondarily infected |
Global Zoonotic Diseases: Viral Diseases and Prion Disease
Disease in Humans | Causative Organism | Animals Involved | Geographic Distribution | Probable Means of Transmission to Humans | Clinical Manifestations in Humans |
|---|---|---|---|---|---|
Viral Diseases | |||||
Alkhurma (Alkhumra) hemorrhagic fever | Alkhurma (=Alkhumra) virus (family Flaviviirdae, genus Flavivirus); variant of Kyasanur Forest virus; member of tickborne encephalitis virus serocomplex | Sheep, goats, camels | Middle East | Ticks (Ornithodoros and Hyalomma spp); direct contact with animal meat via broken skin or ingestion of unpasteurized camel milk linked to some cases | Febrile illness, often with GI signs; encephalitic/neurologic and hemorrhagic signs in some; early reports suggested case fatality up to 25% but probably lower, recently < 1%; subclinical infections may be common |
Barmah Forest virus infection; epidemic polyarthritis | Barmah Forest virus (family Togaviridae, genus Alphavirus) | Natural hosts unknown; horses, brushtail possums, kangaroos might hosts | Australia, Papua New Guinea | Mosquito bites; Culex and Aedes spp implicated; also found in Culicoides midges | Resembles disease due to Ross River virus; fever, rash, and nonspecific clinical signs; myalgia and polyarthralgia can persist for months |
Buffalopox | Vaccinia virus, Buffalopox virus strain (family Poxviridae, genus Orthopoxvirus) | Water buffalo, cattle | Indian subcontinent (south Asia), Indonesia, parts of Middle East | Skin contact with infected animals, often when milking | Pox skin lesions mainly on hands, face, legs, buttocks; occasionally lymphadenopathy, fever, malaise |
California encephalitis virus serogroup (California serogroup) infections | California encephalitis virus serogroup (family Bunyaviridae, genus Orthobunyavirus); includes California, La Crosse, Tahyna, Inkoo, Jamestown Canyon, Morro Bay, Snowshoe hare, Guaroa, Lumbo, Chatanga, and other viruses | Many wild and domestic mammals; major reservoirs and amplifying hosts can differ between viruses | North and South America, Europe, Africa, Asia; possibly worldwide; distribution of each virus varies | Mosquito bites | Syndromes, severity vary with the virus; flu-like illness, meningitis, or encephalitis common with North American viruses |
—La Crosse encephalitis | La Crosse virus (California encephalitis virus serogroup) | Chipmunks, squirrels are major amplifying hosts; other mammals can be infected | North America | Mosquito bites | Many cases mild and flu-like; meningitis or encephalitis with seizures, paralysis, and focal neurologic signs possible; most cases in children; estimated case fatality rate < 1% in cases with encephalitis |
—Tahyna fever | Tahyna virus (California encephalitis virus serogroup) | Hares, rabbits, rodents, hedgehogs, and other mammals | Europe, Asia, Africa | Mosquito bites (culicine and anopheles) | Influenza-like illness, sometimes including GI signs; arthritis or respiratory signs, including bronchopneumonia in some; meningitis possible but appears uncommon; most often in children; does not appear to cause fatal disease |
Camelpox | Camelpox virus | Old World camelids, possibly other species | Middle East, Asia, Africa, possibly other areas; human cases recently described in India in camel handlers, rare unconfirmed cases suggested in other locations | Direct contact | Skin lesions similar to cowpox, variola virus infections |
Chikungunya | Chikungunya virus (family Togaviridae, genus Alphavirus) | Sylvatic cycle in nonhuman primates, possibly rodents in Africa; Asian lineage virus thought to be maintained in humans; however, sylvatic cycle may also exist in some locations | Asia, Africa, Europe, South America | Mosquito bites (especially Aedes spp) | Febrile illness, may have rash and/or GI signs; arthralgia, especially in small joints, and myalgia prominent, may persist for months; myocarditis, neurologic signs, hemorrhages reported in a few cases |
Colorado tick fever | Colorado tick fever virus (family Reoviridae, genus Coltivurus; Salmon River virus and California hare coltivirus may be variants | Rodents and small mammals and other mammals can also be infected | Some regions in western North America | Tick bites (primary vector is Dermacentor andersoni) | Nonspecific febrile illness; pharyngitis, rash, or GI signs possible; biphasic or triphasic in some; complications (eg, neurologic signs, hemorrhages, pericarditis, myocarditis, orchitis) uncommon but can occur in severe cases; deaths rare |
Orf virus (family Poxviridae, genus Parapoxvirus) | Sheep, goats, camelids, wild ungulates; rare cases in dogs and cats | Worldwide | Occupational exposure via contact with broken skin (both live animals and meat processing) | Papule(s) that umbilicate and ulcerate, usually on hands; dissemination rare but has occurred in humans with atopic dermatitis; large lesions refractory to treatment can occur in immunosuppressed | |
Cowpox virus (family Poxviridae, genus Orthopoxvirus) | Rodents are usual reservoir host; also in domestic and wild cats, occasionally cattle, other mammals | Parts of Europe and Asia | Contact exposure via broken skin, bites, scratches | Papules, vesicles that become pustular, to ulcerative nodules, scars; single or multiple lesions, often on hands; regional adenopathy and malaise, flu-like symptoms in some; lesions remain localized in healthy humans; more extensive or generalized disease may occur in children, humans with eczema, immunocompromised; severe cases can involve respiratory mucosa; rare fatal cases (eg, complications of encephalitis) | |
Crimean-Congo hemorrhagic fever virus (family Bunyaviridae, genus Orthonairovirus) | Cattle, water buffalo, rodents, sheep, goats, hares, other mammals, rarely in birds (eg, ostriches) | Africa, Middle East, Asia, parts of Europe where Hyalomma ticks occur | Tick bites, especially Hyalomma but other genera may also transmit; skin, mucous membrane contact with blood or tissues of animals or crushed ticks; ingestion of unpasteurized milk and possibly uncooked animal tissues; rarely airborne; person-to-person transmission occurs, especially via hemorrhage and during close contact | Febrile flu-like signs, GI symptoms; hemorrhagic signs may begin with petechial rash; hepatitis, abortion, other organ involvement in some cases; asymptomatic or mild in some; case fatality rate usually 3%–30% but can be higher | |
Eastern equine encephalomyelitis virus (EEEV), Madariaga virus (former South American EEEV lineages) (family Togaviridae, genus Alphavirus) | Birds are principal reservoir hosts, small mammals might also amplify, snakes might have role in overwintering virus; small mammals (eg, rodents), marsupials might be reservoir hosts for Madariaga virus; clinical cases in equids and occasionally other mammals and birds but domestic animals are almost always dead-end hosts | Americas | Mosquito bites; Culiseta melanura important in EEEV maintenance cycle; Culex spp might be important for Madariaga virus; various mosquito species (Aedes, Coquillettidia, Culex) can transmit to humans | EEEV causes nonspecific febrile illness, which may be followed by severe encephalitis; neurologic sequelae common after encephalitis; case fatality rate 30%–70%;more severe in infants and elderly; Madariaga virus causes similar signs but seems less severe | |
Ebola hemorrhagic fever | Zaire ebolavirus, Sudan ebolavirus, Tai Forest ebolavirus (formerly Ivory Coast ebolavirus), Bundibugyo ebolavirus (family Filoviridae, genus Ebolavirus); Reston ebolavirus does not seem to affect humans | Bats are reservoir hosts for Zaire ebolavirus and suspected reservoir hosts for others; primates, duikers, pigs, possibly other mammals can be infected | Africa | Contact with infected tissues (especially nonhuman primates and duikers), blood; probable transmission from bats in caves; person-to-person transmission occurs | Initially nonspecific febrile illness; maculopapular rash with desquamation; various oral/ pharyngeal mucosal lesions possible; signs of increased vascular permeability, mild to severe bleeding tendency, various other signs (eg, neurologic signs, dyspnea, multiorgan dysfunction) develop a few days after onset; mortality rate 36%–90%, varies with isolate |
Encephalomyocarditis | Encephalomyocarditis virus (family Picornaviridae, genus Cardiovirus); implicated as zoonotic pathogen but few confirmed cases | Rodents, possibly wild boar, may be reservoir hosts; also found in wild and domestic mammals (including swine, nonhuman primates), and wild birds | Worldwide in animals | Probably ingestion of contaminated food or water | Nonspecific febrile illness, sometimes with GI signs, and/or decreased reflexes have been reported in adults, with recovery within several days; implicated in CNS signs, including paralysis in children; most infections may be asymptomatic or mild |
Foot-and-mouth disease virus (family Picornaviridae, genus Aphthovirus, types A, O, C, SAT 1, SAT 2, SAT 3, and Asia 1) | Cattle, swine, sheep, goats, other cloven-hoofed animals (Artiodactyla), a few mammals in other orders | Asia, Africa, Middle East, South America | Contact exposure, typically in laboratories or other high concentrations of virus; broken skin or drinking virus-contaminated unpasteurized milk are recognized routes | Humans may become temporary nasal carriers after field exposure to virus but do not usually become ill; mild influenza-like disease and vesicular lesions (including lesions at site of skin entry) occur very rarely, mostly laboratory associated | |
Hantaviral diseases | |||||
—Hantaviral pulmonary syndrome | Sin Nombre, Black Creek Canal, Bayou, Andes, Choclo, Laguna Negra, and Cano Delgadito viruses, others (family Bunyaviridae, genus Hantavirus) | Reservoirs are rodents, insectivores; each virus tends to be associated with one to a few reservoir hosts; occasionally infect other hosts | North and South America | Aerosols from rodent excretions and secretions; contact with broken skin and mucous membranes; rodent bites; person-to-person transmission reported for Andes virus | Prodromal stage with nonspecific febrile illness; followed by respiratory failure, cardiac abnormalities; hemorrhagic signs possible, mainly with South American viruses; notable kidney disease uncommon; milder illnesses also possible; case fatality rate for most viruses approx. 25%–-40% in classical syndrome |
—Hemorrhagic fever with renal syndrome | Hantaan, Dobrava-Belgrade, Puumala, Seoul, and Amur-Soochong viruses, others (family Bunyaviridae, genus Hantavirus) | Reservoirs are rodents, insectivores; each virus tends to be associated with one to a few reservoir hosts; occasionally infect other hosts | Europe, Asia, Africa; Seoul virus is worldwide | Aerosols from rodent excretions and secretions; contact with broken skin and mucous membranes; rodent bites | Prodromal stage with nonspecific febrile illness; followed by hypotension, renal signs to renal failure with oliguria; hemorrhagic signs, other syndromes (including respiratory) in some; milder illnesses also possible; case fatality rate varies from < 1% (Puumala virus) to 5% (Hantaan virus), and up to 10%–-15% in the past |
Heartland virus disease | Heartland virus (family Bunyaviridae, genus Phlebovirus) | Not known | North America | Vector appears to be Amblyomma americanum tick | Febrile illness with headache, myalgia, arthralgia, diarrhea, thrombocytopenia; some cases fatal (may be associated with comorbidities) |
Hendra virus (family Paramyxoviridae, genus Henipavirus) | Fruit bats are normal reservoir host; horses can be infected | Australia | Direct contact with infected animals (all human cases have been linked with horses) or contaminated tissues | Respiratory infection, encephalitis (including recurrent encephalitis); few cases described but several were fatal | |
Hepatitis E | Hepatitis E virus, mammalian isolates (family Hepeviridae, genus Hepevirus); genotypes 3 and 6, possibly others, are zoonotic; genotypes 1 and 2 maintained in humans | Humans, swine, wild boar, deer, rabbits, ferrets, rats, mongoose, others; swine and probably other hosts are reservoirs for human infections | Worldwide; human and zoonotic genotypes may differ in prevalence between areas | Fecal-oral transmission; consumption of raw or undercooked meat and liver; waterborne, contact with animal reservoirs | Mild, self-limiting hepatitis to liver failure, more severe in pregnancy and can result in abortion, death of newborn, premature birth; usually acute, but can be chronic in organ-transplant patients; case fatality rate < 1% to 4% in general population, up to 20% in pregnant |
Herpes B virus disease | Cercopithecine herpesvirus 1 (McHV, Herpesvirus simiae, B virus) (family Herpesviridae, genus Simplexvirus) | Carried in genus Macaca (Old World macaques), with lifelong latency and potential for periodic shedding after infection; other nonhuman primates susceptible; cell cultures | Worldwide, can be common, especially in closed groups of macaques; human cases rare | Monkey bites and scratches, contamination of mucous membranes with infected saliva, secretions | Influenza-like symptoms; vesicular skin lesions, pain, or itching around wound, followed by severe encephalitis with seizures, paralysis, coma; very high mortality rate in untreated cases |
Influenza virus infections | |||||
—Avian influenza | Influenza A virus (family Orthomyxoviridae, genus Influenzavirus A); avian influenza viruses; many severe human cases linked to Asian lineage H5N1 highly pathogenic avian influenza (HPAI) or H7N9 LPAI viruses; however, other viruses also cause illness | Avian influenza viruses in wild and domestic birds, especially poultry; uncommon in mammals | Worldwide, distribution of strains varies | Usually by contact with infected poultry; avian viruses may be shed in respiratory secretions and feces | Avian influenza viruses can cause conjunctivitis, human influenza-like illness, or severe disease with multiorgan dysfunction, death; severity of disease varies with influenza strain |
—Swine influenza | Influenza A virus (family Orthomyxoviridae, genus Influenzavirus A); swine influenza viruses | Usually in pigs; also turkeys; can infect mink, ferrets | Worldwide | Usually by contact with infected animals; swine influenza viruses occur in respiratory secretions | Seems to resemble human influenza; severity of disease varies; fatal cases have been reported uncommonly |
Japanese encephalitis (Japanese B encephalitis) | Japanese encephalitis virus (family Flaviviridae, genus Flavivirus) | Swine, wild birds are important maintenance and amplifying hosts; horses ill but epidemiologically unimportant in amplification; other mammals, reptiles, amphibians may be infected, usually subclinically | Asia, parts of western Pacific islands and Australia | Mosquito bites especially Culex; Culex tritaeniorhynchus important in maintenance cycle; also through broken skin or mucous membranes after direct contact with infected tissues | Nonspecific febrile flu-like illness can progress to severe encephalitis or less common neurological syndromes (eg, flaccid paralysis) in some; neurologic sequelae very common in survivors of encephalitis; reported case fatality rates < 5%–40% |
Kyasanur Forest disease | Kyasanur Forest virus (family Flaviviridae, genus Flavivirus); member of tickborne encephalitis virus serocomplex | Rodents, shrews, other small mammals, ground-feeding birds thought to be reservoirs; affects monkeys; possible infections in other mammals, birds | India | Tick bites (especially Haemaphysalis spp, also others) | Nonspecific febrile illness; characteristic papulovesicular eruption on upper soft palate in some; course may be biphasic; hemorrhagic signs (eg, ecchymoses, purpura, petechiae, GI bleeding, epistaxis) and/or neurologic signs possible in second stage; prolonged convalescence in many; case fatality rate ~3% |
Lassa fever | Lassa virus (family Arenaviridae, genus Mammarenavirus) | Wild rodents, multimammate mouse is major host | West Africa | Contact with rodent excretions, secretions, or tissues; aerosols | Gradual onset of nonspecific febrile illness, may be followed by chest pain, cough, GI signs, hepatitis; severe swelling of head and neck, hypotension/shock can develop; pleural/pericardial effusions; hemorrhagic syndrome less common; overall mortality rate 1% in endemic areas; case fatality rate 15%–20% among hospitalized patients |
Louping ill (Ovine encephalomyelitis) | Louping ill virus (family Flaviviridae, genus Flavivirus) | Sheep and red grouse are primary reservoirs; also reported in goats, South American camelids, cattle, horses, dogs, farmed cervids, other domestic and wild mammals; some birds related to grouse (eg, ptarmigan) are susceptible to experimental infection | UK, Northern Ireland; also reported in Norway, Denmark (island of Bornholm), part of eastern Russia; similar viruses in Spain, Greece, Turkey; historically in Bulgaria and possibly Japan | Usually tick bites (Ixodes ricinus) in animals but this route appears uncommon in humans; aerosol exposure in laboratory; contamination of skin wounds and mucous membranes after contact with cultures, infected animals or their tissues; possibly ingestion of milk; human illnesses seem to be rare and mostly laboratory associated | Biphasic influenza-like illness, sometimes followed by meningitis or meningoencephalitis, or polio-like paralytics, syndrome in second phase; case fatality rate appears low |
Lymphocytic choriomeningitis | Lymphocytic choriomeningitis virus (family Arenaviridae, genus Mammarenavirus) | Reservoir mainly house mouse; can be maintained in some other mice, hamster populations; also infects guinea pigs, chinchillas, rats, nonhuman primates, some other mammals | Worldwide | Direct or indirect contact with host excretions and secretions (via mucous membranes, broken skin, aerosols); bites; possibly ingestion | Ranges from mild flu-like illness to biphasic with meningitis in second phase; complications (eg, arthritis of hands, parotitis, orchitis) possible; can cause congenital defects (CNS defects, chorioretinitis, and other ocular lesions) or abortion; rarely fatal in immunocompetent (overall case fatality rate < 1%); serious and life-threatening multisystemic disease in transplant patients |
Marburg hemorrhagic fever | Marburg virus, Ravn virus (family Filoviridae, genus Marburgvirus) | Bats are reservoir hosts; primates can be infected | Africa | Contact with infected tissues (especially nonhuman primates); probable transmission from bats in caves | Initially nonspecific febrile illness; maculopapular rash with desquamation; hepatitis; signs of increased vascular permeability, mild to severe bleeding tendency, various organ dysfunctions develop a few days after onset; mortality rate 20%–88%, varies with isolate |
Menangle virus infection | Menangle virus (family Paramyxoviridae) | Fruit bats are normal reservoir host; pigs can also be reservoir | Australia | Close direct contact with tissues, amniotic fluid or blood of pigs reported in human cases | Severe illness with fever, severe headache, myalgia, lymphadenopathy, drenching sweats, macular rash |
Middle East respiratory syndrome (MERS) | MERS coronavirus | Dromedary camels source of virus for many cases in humans; bats might be a reservoir | Middle East; serologic evidence for virus in Africa | Contact with nasal secretions from camels; evidence for virus in unpasteurized camel milk, various tissues; possibly other virus sources | Asymptomatic or mild upper respiratory signs or flu-like illness to pneumonia; more severe in humans with coexisting illness or immunosuppression, elderly, but also in healthy; multiorgan failure possible; reported case fatality rates 20% or higher in confirmed cases but serologic evidence suggests milder cases probably missed |
Milker’s nodules (pseudocowpox) | Pseudocowpox virus (family Poxviridae, genus Parapoxvirus) | Cattle | Worldwide | Skin contact (especially broken skin) with lesions on cow’s udder or mouth of calf; also from fomites | Papular to nodular red skin lesions; self-limiting |
Monkeypox | Monkeypox virus (family Poxviridae, genus Orthopoxvirus); Congo Basin clade causes more severe illness than West African clade | Nonhuman primates, some wild and pet rodents, including Gambian rats, dormice, prairie dogs, African squirrels, dogs, some other mammals (eg, opossums); full host range uncertain | West and central Africa | Contact with lesions, blood or body fluids, fomites; bites; aerosols during close contact | Smallpox-like disease; flu-like symptoms followed by maculopapular rash, which develops into vesicles, pustules, scabs; lymphadenopathy prominent; respiratory signs, encephalitis possible; case fatality rate varies with strain, < 1% to 10%–17% or higher; milder in those vaccinated for smallpox |
Murray Valley encephalitis | Murray Valley encephalitis virus (family Flaviviridae, genus Flavivirus) | Wild water birds are reservoirs; rabbits, kangaroos may also amplify virus; some other mammals (eg, horses), dead-end hosts | Australia, New Guinea | Mosquito bites, especially Culex annulirostris | Asymptomatic or mild nonspecific febrile illness in majority; encephalitis, often with neurologic sequelae, or poliomyelitis-like flaccid paralysis in small number of patients; case fatality rate 15%–30% in encephalitic form |
Newcastle disease | Newcastle disease virus (Avian paramyxovirus 1 [family Paramyxoviridae, genus Avulavirus]) | Domestic and wild birds | Mildly virulent (lentogenic, mesogenic strains) are found worldwide; highly virulent (velogenic) strains found in Asia, the Middle East, Africa, Central and South America, parts of Mexico; also in cormorants in US | Occupational exposure, usually after contact with large amounts of virus | Highly virulent (velogenic) strains can cause self-limiting conjunctivitis, possibly other syndromes (eg, mild influenza-like disease); fatal pneumonia in a severely immunocompromised person |
New World hemorrhagic fever (Argentinean, Bolivian, Venezuelan and Brazilian hemorrhagic fevers) | Arenaviruses in Tacaribe complex (family Arenaviridae, genus M Ammarenavirus): Juin virus (Argentine hemorrhagic fever), Machupo virus (Bolivian hemorrhagic fever), Guanarito virus (Venezuelan hemorrhagic fever), Sabiá virus (Brazilian hemorrhagic fever), Chapare virus; possibly others | Rodents | South America | Viruses found in rodent excretions, secretions, tissues; inhalation of aerosolized virus or direct contact with mucous membranes or broken skin | Gradual onset of nonspecific clinical signs, including myalgia, headache, and fever; may develop petechial or ecchymotic hemorrhages, bleeding, CNS signs, hypotension/shock; case fatality rates differ between viruses |
Nipah virus (family Paramyxoviridae, genus Henipavirus) | Fruit bats of the genus Pteropus are normal reservoir; swine can be reservoir; occasionally in other mammals (spillover hosts) | Malaysia, Bangladesh, Northern India; apparent outbreak (or closely related virus) in Philippines; virus is probably endemic in southeast Asia; however, outbreaks seem to cluster in certain geographic areas | Direct contact with infected pigs or contaminated tissue; direct or indirect (eg, contaminated fruit juice) bat-to-human transmission; outbreak in Philippines linked to contact with horses; person to person transmission occurs | Initial signs flu-like with fever, headache, myalgia, sometimes vomiting; encephalitis and meningitis; respiratory disease, including acute respiratory distress syndromes in some; septicemia; other complications in severely ill; case fatality rate 38%–75% | |
Omsk hemorrhagic fever | Omsk hemorrhagic fever virus (family Flaviviridae, genus Flavivirus); member of tickborne encephalitis virus serocomplex | Voles, muskrats; also found in other animals | Siberia | Tick bites (Dermacentor spp); direct contact with body fluids or carcasses of muskrats and possibly other animal hosts | Biphasic febrile illness with headache, GI signs, ± hemorrhages (nose, gums, lungs, uterus); CNS signs in minority of patients; mortality rate < 3% |
Powassan virus encephalitis | Powassan virus (family Flaviviridae, genus Flavivirus); member of tickborne encephalitis serocomplex | Rodents and other small mammals thought to be reservoirs; evidence for infection in many other mammals, some birds | North America, eastern Russia | Tick bites, especially Ixodes spp, possibly other routes of transmission | Nonspecific febrile illness; may progress to neurologic signs, which can sometimes be severe; some cases fatal |
Rabies and rabies-related infections | Lyssaviruses:rabies virus (family Rhabdoviridae, genus Lyssavirus) and related lyssaviruses, Duvenhage virus, Mokola virus, Australian bat lyssavirus, European bat lyssaviruses 1 and 2, Irkut virus, possibly others | Wild and domestic canids, Mustelidae, Viverridae, Procyonidae, and order Chiroptera (bats) are important reservoir hosts for rabies; bats are reservoir hosts for the rabies-related viruses except Mokola virus, which might be carried in rodents and shrews; probably all mammals are susceptible | Rabies is worldwide with a few exceptions: rabies-related lyssaviruses are found only in eastern hemisphere (distribution varies) | Exposure to saliva of diseased animals through broken skin or mucous membranes, often in bites; aerosols in closed environments | Paresthesias or pain at bite site; nonspecific prodromal signs such as fever, myalgia, malaise; mood changes progress to paresthesias, paresis, seizures, and many other neurologic signs; survival in clinical cases thought to be very rare |
Rift Valley fever virus (family Bunyaviridae, genus Phlebovirus) | Sheep, goats, cattle, water buffalo, African buffalo, camels, nonhuman primates; squirrels and other rodents; puppies and kittens | Africa | Mosquito bites; contact with animal tissues, aerosolized virus in laboratories or animal slaughter | Influenza-like febrile illness in most; complications can include renal disease, meningoencephalitis, ocular disease or hemorrhagic syndrome with liver involvement; death uncommon except with hemorrhagic syndrome | |
Ross River virus infection, Ross River fever; epidemic polyarthritis | Ross River virus (family Togaviridae, genus Alphavirus) | Marsupials, important amplifying hosts; possibly also amplified by horses, other mammals during epizootics | Australia, South Pacific Islands | Mosquito bites (especially Culex annulirostris and Aedes spp) | Mild fever, arthralgia ± arthritis, headache, rash; small joints most affected but large joints can also be involved; arthralgia, myalgia, lethargy may persist for months |
St. Louis encephalitis | St. Louis encephalitis virus (family Flaviviridae, genus Flavivirus) | Wild birds are major hosts; mammals (eg, rodents, bats) might also be involved in some locations | Western hemisphere | Mosquito bites, especially Culex spp | Flu-like illness sometimes followed by meningitis or encephalitis, focal neurologic signs; more severe in elderly and those with debilitating diseases; case fatality rate of 5%–20% reported in epidemics |
Severe acute respiratory syndrome (SARS) | SARS coronavirus (family Coronaviridae, genus Coronavirus) | Bats are thought to be reservoir hosts; can also infect palm civets, raccoon dogs, cats, pigs, ferrets, rodents, nonhuman primates, other mammals; palm civets might have role in transmission to humans but uncertain | China, southeast Asia | Contamination of mucous membranes with respiratory droplets or virus on fomites; possibly aerosol transmission | Mild upper respiratory or flu-like illness (sometimes with diarrhea) to severe pneumonia; generally more severe in people with comorbidities, elderly or immunocompromised, but also severe in some healthy people; multiorgan failure possible; fatality rate among known cases ranged from 6%– 17% in different areas |
Severe fever with thrombocytopenia syndrome (SFTS) | SFTS virus (family Bunyaviridae, genus Phlebovirus); agent appears related to heartland disease virus | Reservoir host unknown; antibodies or viral RNA found in various domestic and wild mammals | Asia | Tick bites (Haemaphysalis longicornis and members of other genera) | Febrile illness with GI signs; thrombocytopenia; multiple organ failure possible; some cases fatal |
Sindbis virus disease | Sindbis virus (family Togaviridae, genus Alphavirus) | Birds (passeriformes are main reservoirs or amplifying hosts); occasionally found in other vertebrates | Virus widespread in Eastern hemisphere; outbreaks tend to occur in limited locations but sporadic cases can occur anywhere | Mosquito bites; Culex and Culiseta, also others (eg, Aedes that act as bridge vectors) | Fever, arthritis, rash, prominent myalgia; nausea, vomiting, mild jaundice in some; joint pain can persist for months; seems to be mild or asymptomatic in most children; fatalities appear absent or very rare |
Tanapox | Tanapox virus (family Poxviridae, genus Yatapoxvirus); Yaba-like disease virus may be a variant of tanapox virus | Nonhuman primates | Africa, and in monkey colonies | Direct contact through broken skin; mosquitoes suspected to be vector in Africa | Nonspecific febrile illness followed by self- limited papulovesicular or nodular lesions (may be pruritic or tender), often on extremities; number of lesions varies but often 1–2 |
Tickborne encephalitis (far eastern tickborne encephalitis, Russian spring-summer encephalitis, central European tickborne encephalitis) | Tickborne encephalitis virus (TBEV) (family Flaviviridae, genus Flavivirus); three major subtypes: European (TBEV-Eu [least virulent]), Siberian (TBEV-Sib), Far Eastern (TBEV-FE) | Small mammals especially rodents; important in maintaining virus; ruminants, dogs, horses, and other mammals; birds can be infected | Eurasia; TBEV-Eu mainly Europe to former USSR; TBEV-FE mainly Asia to former USSR; TBEV-Sib mainly in Siberia | Tick bites (mainly Ixodes ricinus and I persculatus; also other species); may be ingested in unpasteurized milk and milk products | Often biphasic, with flu-like febrile illness in initial stage; neurologic signs from mild meningitis to severe encephalitis in some; myelitis or flaccid poliomyelitis-like paralysis (usually arms, shoulders, levator muscles of head); possibility of chronic and progressive forms; cases with hemorrhagic signs reported in parts of Russia; case fatality rate in Europe (mainly TBEV-Eu) < 1% but some subtypes seem to have higher mortality |
Usutu virus infections | Usutu virus (family Flaviviridae, genus Flavivirus) | Birds are reservoir hosts; infections also occur in various mammals including horses, dogs, suids, rodents | Africa, Europe, Middle East | Mosquito bites, mainly Culex spp | Febrile flu-like illness, sometimes with rash; jaundice possible; encephalitis or meningoencephalitis in some; neurologic complications might occur mainly in people with comorbidities or immunosuppression; many cases might be mild/asymptomatic |
Vaccinia-related poxviruses | Vaccinia or vaccinia-like viruses (family Poxviridae, genus Orthopoxvirus) of uncertain origin | Reservoir uncertain; found in wild rodents, cattle, horses, nonhuman primates | Appear to be endemic in Brazil | Direct contact | Pox skin lesions (papules, pustules, ulcerative nodules), may be accompanied by fever, lymphadenopathy |
Venezuelan equine encephalomyelitis | Venezuelan equine encephalitis virus (VEEV) complex (family Togaviridae, genus Alphavirus) | Enzootic VEEV maintained in rodents, other small mammals, bats, not amplified in equids; epizootic viruses amplified in equids; occasionally in other mammals and birds | Western Hemisphere; enzootic strains probably Florida to South America; epizootic strains emerge in South America, spread, including to North America | Mosquito bites (epizootic VEEV mainly Culex; enzootic VEEV by multiple genera); epizootic viruses possibly also by mechanical vectors including blackflies; exposure to aerosolized debris from infected laboratory rodents; laboratory accidents | Most have nonspecific febrile illness, can be followed by neurologic signs in a small percentage of cases, especially children and to a lesser extent the elderly; encephalitis has case fatality rate of 10%–35% with highest rates in children < 5 yr old; fetal losses in some pregnant women |
Vesicular stomatitis | Vesicular stomatitis Indiana virus, vesicular stomatitis New Jersey virus, vesicular stomatitis Alagoas virus, and Cocal virus (family Rhadboviridae, genus Vesiculovirus) | Equids, swine, cattle; occasionally in South American camelids, sheep, and goats; also rodents; serologic evidence of infection in many wild mammals | North and South America; most likely not endemic north of Mexico but sporadic outbreaks | Contact with animals (lesions, secretions) or in laboratory, probably also from insect bites, including mosquitoes and biting flies (Lutzomyia spp, Culicoides midges, and blackflies) | Usually asymptomatic; may develop acute, self-limited, febrile flu-like illness; vesicles sometimes found in mouth, pharynx, or inoculation site (eg, hands); one case of encephalitis in young child attributed to VSV |
Wesselsbron fever | Wesselsbron virus (family Flaviviridae, genus Flavivirus) | Ruminants, especially sheep, goats; also evidence of infection in other mammals, including rodents; lemurs; can infect birds | Africa | Mosquito bites (mainly Aedes spp, possibly others); also by contact with contaminated material especially in the laboratory | Nonspecific febrile illness ± maculopapular rash or ocular signs in some; few cases described but seems to be self-limiting; one case of encephalitis after accidental laboratory exposure of eye |
West Nile virus (family Flaviviridae, genus Flavivirus); lineage 1 and lineage 2 viruses are both pathogenic | Birds are primary reservoir hosts; also affects horses, other mammals, alligators, possibly other reptiles and amphibians | Eastern and western hemisphere | Mosquito bites (primarily , Culex spp); also by handling infected birds or reptiles or their tissues | Nonspecific febrile illness, occasionally with rash; some cases progress to encephalitis, meningitis, and/or acute flaccid paralysis that resembles poliomyelitis; occasionally other syndromes; < 1% develop neurologic disease but case fatality rate ~10% in all patients with this form and higher in the elderly | |
Western equine encephalomyelitis virus (family Togaviridae, genus Alphavirus) | Birds are reservoir hosts, may also cycle in jackrabbits; equids and other mammals are dead-end (incidental) hosts and do not amplify; reptiles might help overwinter | Americas | Mosquito bites; Culex tarsalis important in maintenance cycle in birds in North America; also transmitted by other genera especially Aedes | Nonspecific febrile illness may be followed by encephalitis in infants and children, uncommonly in healthy adults; case fatality rate 3%–4% | |
Yellow fever | Yellow fever virus (family Flaviviridae, genus Flavivirus); only sylvatic cycle is zoonotic (humans are reservoir for urban cycle) | Nonhuman primates | South America, Africa | Mosquito bites (Haemagogus spp and Sabethes spp in sylvatic cycles in South America, Aedes spp in sylvatic cycles in Africa) | Nonspecific, mild to severe febrile illness followed by liver and renal failure in some; hemorrhages (eg, epistaxis, hematemesis, melena, uterine hemorrhage) and often jaundice in severe cases; can be fatal |
Zika virus infection | Zika virus (family Flaviviridae) | Nonhuman and human primates are likely the main reservoirs of the virus | Africa, the Americas, Southern Asia, Western Pacific | Mosquito bites (infected Aedes mosquitoes [A aegypti and A albopictus]) | Many people are asymptomatic; acute onset of fever with maculopapular rash, arthralgia, conjunctivitis, myalgia, headache; there have been cases of Guillain-Barré syndrome reported in patients following suspected Zika virus infection; infection during pregnancy is a cause of microcephaly and other severe fetal brain defects |
Prion Disease | |||||
Variant Creutzfeldt-Jakob disease | Bovine spongiform encephalopathy prion | Cattle are most important host; also infects other ruminants, cats and other felids, lemurs | Most cases in the UK but also in many other countries | Ingestion of bovine products, especially those contaminated with CNS tissues | Neurodegenerative disorder similar to sporadic Creutzfeldt-Jakob disease but often in younger patients and progresses more rapidly; always fatal |
The tables in this topic list zoonotic bacterial, viral and prion, fungal, and parasitic diseases. Many proven zoonoses, including some diseases that are rare in humans, organisms that are maintained primarily in humans, some primate diseases, and diseases due to fish and reptile toxins have been omitted. The tables are intended to give a general clinical picture of each disease; current medical texts or review articles should be consulted for a more complete description. Clinical signs are listed; asymptomatic infections can also be assumed to occur in most cases. Many pathogens can cause more severe disease or unusual signs in immunocompromised patients.
An indication of the mortality rate among healthy humans has been provided for many infections. However, there is almost always a chance of death whenever lesions can become generalized, vital organs may be affected, secondary infections occur, or the patient is immunocompromised or has other comorbidities. The mortality rate is often influenced by the availability of medical care, and it is generally lower when advanced medical support is available. The risk of death from some bacterial diseases with high mortality rates can be nearly eliminated with prompt antimicrobial treatment.
Information on the geographic range of an organism should be taken as a rough guide. The precise ranges of many pathogens have not been completely determined. Organisms may also expand their range or be eradicated from areas where they were once abundant. A geographic distribution described as worldwide means organisms are widespread and found on all major continents, although they may absent from some areas (eg, polar regions or some islands). In some cases, organisms indicated as being present on a continent may nevertheless have a limited distribution.
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