avian & livestock assay data sheet
Avian polyomavirus (APV)
detection of avian polyomavirus by real time polymerase chain reaction
included in the psittacine PCR
polyomavirus causes budgerigar fledgling disease. The virus has
a double-stranded DNA genome. It has a worldwide distribution
and is one of the most significant pathogens of fledglings of
caged birds such as macaws, conures, eclectus parrots,
ring-necked parrots, lovebirds, and budgerigars. Polyomavirus is
highly infectious, although many infections may be asymptomatic.
Disease in adult birds is rare and may require a simultaneous
infection with Psittacine Beak and Feather Disease Virus.
infected with APV can develop abdominal distention and a feather
abnormality known as “French molt”. The disease causes a lack of
down feathers on the back and abdomen, filoplumes on the head
and neck, and subcutaneous hemorrhage, sometimes culminating in
mortality. APV and PBFD (psittacine beak and feather disease)
virus cause similar feather abnormalities and it is difficult to
differentiate the viral etiology based on clinical
presentations. However, it is important to differentiate them
since treatments and countermeasures differ for the two
budgerigars may develop as soon as 9 days after infection but
may take as long as 2 weeks in other species. Following the
start of viremia, virus can be detected in cloacal swabs. The
sample of choice is blood as it has been shown in cockatoos and
conures that viral DNA can be consistently detected in the blood
of viremic birds but only intermittently in cloacal swabs.
Infected nestling parrots can shed virus for up to 16 weeks,
whereas adult birds may shed virus for only 6 weeks or less.
methods, such as immunoflourescence and electron microscopy,
have been used to detect APV and differentiate APV infection
from PBFD. Among these methods, PCR detection remains the most
sensitive, specific and rapid (Phalen et al., 1991).
Furthermore, a wide variety of samples can be tested using PCR,
such as blood, cloacal swabs, fecal dust and fresh or
recommend screening individual birds without a history by PCR
analysis of blood. Blood from adult birds testing positive for
the virus should be retested in 4 to 6 weeks. Juvenile birds
testing positive should be retested in 12 to 16 weeks. If the
infected bird is blood-negative in the second test, an
additional test should be done on a cloacal swab to ensure that
it is no longer shedding virus in the droppings.
trials indicate that polyomavirus DNA is not detectable in the
blood of uninfected birds following vaccination for APV.
Veterinarians must therefore conclude that if a bird’s blood
tests positive by PCR, it is infected with polyomavirus
regardless of whether it was recently vaccinated, and that the
bird is most likely shedding the virus.
Help confirm the disease causing agent
Help ensure that bird populations are free of APV
Early prevention of spread of the virus among bird
Minimize human exposure to the virus
Safety monitoring of biological products and vaccines
that derive from birds
Phalen, D.N., Wilson, V.G. and Graham, D.L. (1991) Polymerase
chain reaction assay for avian polyomavirus. J Clin
0.2 ml whole blood in EDTA (purple top) or ACD (yellow top)
tube, or 0.2 ml feces, or cloacal swab, or swab of the outer
surface of liver, spleen or kidney, or 0.2 ml fresh, frozen or
types other than those listed here, please call to confirm
specimen acceptability and shipping instructions.
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
2 business days
Qualitative real time PCR