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 with avian polyomavirus (APV).


METHODS
Case series.


METHODS
92 parrots in 2 aviaries.


METHODS
Blood samples were obtained from parrots naturally exposed to APV during a 3- to 4-month period for determination of serum virus neutralizing 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 developed simultaneously with or was followed within 1 week by cloacal virus shedding and antibody production. Cloacal virus shedding continued after viremia ceased. During viremia, viral DNA was detected continuously in blood samples. Viral DNA was detected in serial cloacal swab specimens in most birds, but it was detected inconsistently in 6 birds and not detected in 3 birds, even though these birds were viremic. Duration of cloacal virus shedding was < or = 4.5 months. In 1 aviary, prevalence of infection 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 infection was > or = 90%. For all affected birds, infection could be detected 18 days after the first death.


CONCLUSIONS
If a single sampling is used for polymerase chain reaction detection of viral DNA, blood and cloacal swab specimens are required. In nestling nonbudgerigar parrots, cloacal virus shedding may persist for 4.5 months. Management protocols alone are sufficient to prevent introduction of APV into a nursery.
Phalen
D N
DN
Department of Large Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station 77843, USA.
Radabaugh
C S
CS
Dahlhausen
R D
RD
Styles
D K
DK
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood; D001715:Bird Diseases / Q000453:epidemiology / Q000276:immunology / Q000821:virology*; D002988:Cloaca / Q000821:virology; D004279:DNA, Viral / Q000032:analysis / Q000097:blood; D004196:Disease Outbreaks / Q000662:veterinary; D010311:Parrots; D011120:Polyomavirus / Q000276:immunology / Q000502:physiology*; D027601:Polyomavirus Infections / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D015995:Prevalence; D013781:Texas / Q000453:epidemiology; D014412:Tumor Virus Infections / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D014766:Viremia / Q000453:epidemiology / Q000276:immunology / Q000662:veterinary / Q000821:virology; D017201:Virus Shedding
D000914:Antibodies, Viral; D004279:DNA, Viral