The intestinal virome and how viruses affect intestinal health

The economic impact of enteric virus infections on the poultry industry is represented by several losses due to impairment, associated infection with enteric bacteria, and mortality. Enteric virus predominates in young birds due to the susceptibility of newborn baby chicks, and it may also impact all bird age groups.

The disease has been called pale bird syndrome and helicopter wing disease. Poor growth and retarded feather development have been observed more consistently, along with other, less frequent clinical signs, including diarrhea, increased mortality, pancreatic and lymphoid atrophy. Runting and stunting syndrome (RSS) seems to be the most suitable denomination for this disease, which provides the most appropriate reflection of the clinical findings, suggesting that these cases probably present the same infectious agents.

Interestingly, enteric virome studies of poultry have revealed a highly diverse viral population; however, most of these viruses have not been associated with enteric problems. However, some genera have been associated with enteric problems, embryonic mortality, and first-week culling with consequences until the end of the production cycle, especially in broilers. The main genera involved in enteric problems are Avastrovirus (avastrovirus 1, avastrovirus 2 – ANV 1 and 2, avastrovirus 3 – turkey astrovirus and duck astrovirus), Aveparvovirus (chicken and turkey parvovirus are members of Galliform aveparvovirus 1 species), Rotavirus (rotavirus species A to I, mostly A), Orthoreovirus (avian reovirus), and Aviadenovirus (fowl adenoviruses with 5 species -A to E; and 12 serotypes – 1 to 7; 8a to 8b, and 9 to 11), among others.

In general, analysis of the enteric virome is essential for detecting evidence of new viruses and yet consolidate those that are considered important and associated with enteric problems, according to the clinical pathological manifestations.

Presented at the 7th International Conference on Poultry Intestinal Health, Cartagena, Colombia, 2022. For information on the next edition, click here.