Persistent viraemia in chickens subsequent to<i>in ovo</i>inoculation of reticuloendotheliosis virus

Abstract

Embryonated chicken eggs were inoculated with reticuloendotheliosis virus (REV), and the hatched chicks were reared until the age of 6 months. These birds were found to be viraemic and remained so for the entire duration of the experiment. In agar gel precipitation tests (AGPT) their sera reacted as REV antigen. Infective REV was demonstrated in these sera by inoculation of cell cultures or chickens. The viraemic birds responded poorly to Newcastle disease vaccine. Using the AGPT, a number of birds with REV antigen in their sera could be detected, in addition to the birds with REV antibody, in both turkey and chicken field flocks.