A new member of the psittacosis-lymphogranuloma group of viruses that causes infection in calves.

From portions of intestine and feces of apparently normal calves, a virus that produces elementary bodies was procured in guinea pigs and in embryonated eggs. Morphologically and tinctorially this virus closely resembled members of the psittacosis-lymphogranuloma group of viruses and it shared a common antigen or antigens with them. Comparison of serological, pathogenic, and other properties indicated that this virus from calves is a new member of the psittacosis-lymphogranuloma group and in keeping with classification practices it is provisionally named Miyagawanella bovis. Miyagawanella bovis when fed to experimental calves established an infection in the intestinal tract that resembled the inapparent infection seen in natural cases but failed to produce evident disease. Ability of the virus to infect experimental animals by feeding, and its presence in feces of infected animals indicate its natural mode of spread. This method of dissemination and persistence of virus for long periods of time in infected animals suggested the virus should be widespread and more than 60 per cent of the calves in the vicinity of lthaca were found to be infected.