Overview of Viral Enteritis in Poultry

Numerous viruses are associated with enteric diseases of poultry. Enteric diseases in poultry are among the most difficult to diagnose due to the similarity of clinical signs and gross lesions observed among the diverse group of pathogens associated with diseases. Diagnosis also can be difficult due to confounding issues, such as the presence of viruses in healthy birds, variable pathogenicity and age-related resistance, and coinfection by multiple viruses and other nonviral pathogens. The economic impact of enteric diseases is substantial and results in financial losses due to decreased production and increased costs of getting birds to market.

Enteric viruses are often associated with complex syndromes, such as malabsorption syndrome of broiler chickens and poult enteritis mortality syndrome of turkey poults. Enteric viruses are also associated with nonenteric diseases, such as tenosynovitis caused by infection with avian orthoreoviruses.

Despite rapid advancements in the development of diagnostic testing technologies, limited diagnostic tests are available for the industry; most rely on detection of the viral genome's nucleic acid by PCR or RT-PCR assays. No serological or transmission electron microscopy tests are available in US avian diagnostic labs.

Metagenomic studies of complex enteric diseases affecting poultry have led to identification of prevalent virus families and include coronaviruses, rotaviruses, astroviruses, parvoviruses, and picornaviruses (1, 2, 3, 4).