The pathogenesis of turkey origin reoviruses in turkeys and chickens.

Avian reoviruses that have been shown to be genetically distinct from chicken origin reoviruses were isolated from commercial turkey flocks in the Southeastern US and Texas that were experiencing enteritis. The pathogenesis of these turkey origin reoviruses (TRVs) was evaluated in commercial and specific pathogen free (SPF) turkey poults and SPF chickens. Mortality, clinical disease, gross lesions, microscopic lesions and body weights were observed. TRVs replicated poorly and did not cause disease in chickens. Clinical disease induced by the TRV isolates, characterized by diarrhoea and depression, was mild in both SPF and commercial origin poults. Several TRV isolates caused moderate to severe bursal atrophy in poults. Additionally, each of the TRV isolates caused significant body weight decreases in SPF and/or commercial poults as compared with sham inoculates. Molecular characterization of the isolates revealed that the TRVs and chicken origin reoviruses had identical electropherotype profiles.