Viremia, virus shedding, and antibody response during natural avian polyomavirus infection in parrots

Objective-To determine rapidity of Spread and onset and duration of viremia . virus shedding, and antibody production in parrots naturally infected wit h avian polyomavirus (APV). Design-Case series. Animals-92 parrots in 2 aviaries. Procedure-Blood samples were obtained from parrots naturally exposed to APV during a 3- to 4-month period for determination of serum virus neutralizin g antibody and detection of viral DNA. Nestlings from the next year's hatch were monitored for APV infection. Results-The first indication of inapparent infection was viremia, which dev eloped simultaneously with or was followed within 1 week by cloacal virus s hedding and antibody production. Cloacal virus shedding continued after vir emia ceased. During viremia, viral DNA was detected continuously in blood s amples. Viral DNA was detected in serial cloacal swab specimens in most bir ds, but it was detected inconsistently in 6 birds and not detected in 3 bir ds, even though these birds were viremic. Duration of cloacal virus sheddin g was less than or equal to 4.5 months. in 1 aviary, prevalence of infectio n was 88% and dissemination of virus through the 3-room building required 4 .5 months. In the second aviary,a single-room nursery, prevalence of infect ion was less than or equal to 90%. For all affected birds, infection could be detected 18 days after the first death. Conclusions and Clinical Relevance-if a single sampling is used for polymer ase chain reaction detection of viral DNA, blood and cloacal swab specimens are required. In nestling nonbudgerigar parrots, cloacal virus shedding ma y persist for 4.5 months. Management protocols alone are sufficient to prev ent introduction of APV into a nursery.