Experimental infection of chickens with an Australian strain of reticuloendotheliosis virus. 2. Serological responses and pathogenesis

Abstract

Fifteen SPF chickens were inoculated with an Australian strain of reticuloendotheliosis virus (REV) at 1 day of age and five uninoculated chickens were readily infected by horizontal spread from this group. Antibody detectable by the immunofluorescent antibody (IFA) test developed 3 to 6 weeks after infection, and usually persisted for 20-35 weeks, with maximum titres (40-1280) at 8 to 13 weeks. Agar gel precipitin (AGP) reactions developed more slowly and were variable in duration, the highest proportion of positive reactions being detectable 8 to 13 weeks after infection and persisting for 8 to 30 weeks. Infectious REV was readily detected in the plasma and serum of inoculated chickens 6 weeks after infection and a non-infectious REV antigenaemia usually persisted for at least a further 7 weeks, in the presence or absence of antibody. Development of a detectable REV viraemia was strongly associated with poor body development and premature mortality among the inoculated chickens. In two inoculated chickens which failed to develop detectable serological reactions, a REV viraemia occurred which persisted throughout life. At autopsy, REV was re-isolated from the kidneys of most of the inoculated chickens and from the reproductive and intestinal systems of two birds 22 and 56 weeks after infection.