Viral agents associated with poult enteritis and mortality syndrome: The role of a small round virus and a turkey coronavirus

Intestinal samples from turkey poults affected with poult enteritis and mor tality syndrome (PEMS) were examined for viruses by immune electron microsc opy and double-stranded RNA virus genome electropherotyping. Turkey coronav irus (TCV), avian rotaviruses, reovirus, and a yet undefined small round vi rus (SRV) were detected. The SRV and TCV were isolated and propagated in tu rkey embryos. Challenge of specific-pathogen-free turkey poults with SRV, T CV, or both resulted in mortality and clinical responses similar to those o f natural PEMS. Our experiments indicate that SRV and TCV are possibly impo rtant agents in the etiology of PEMS and the combination of these infection s might result in outbreaks with high mortality. The severity of clinical s igns and mortality of PEMS are postulated to be partly related to the virus agents involved in individual outbreaks.