avian & livestock assay data sheet
Psittacine beak and feather disease virus (PBFD)
- aka psittacine circovirus
Test
code:
S0088
-
Ultrasensitive qualitative detection of PBFD virus by real time polymerase chain reaction
S0088 is
included in the psittacine PCR
screening panel
Psitticine
beak and feather disease (PBFD) is a chronic disease
characterized by feather dystrophy and loss, beak deformity and
ultimately, death. It is caused by a non-enveloped icosahedral
DNA virus belonging to the family Circoviridae. The disease has
been reported in Australia, North America, Europe and Asia. Most
species of parrots, such as cockatoos, African grey parrots,
eclectus parrots and lovebirds, can be infected by this virus.
Recent study also shows that PBFDV can cause feathering problems
in some of the ringneck parakeets and budgerigars in South
Africa.
PBFD virus
usually infects birds less than 3 years of age. The virus is
spread from mother to egg or directly to chicks. Viral particles
can be spread in feather dust carried by air currents, dried
feces or even on the clothing of human handlers. Nest materials,
feeding formula, feeding utensils, nets, bird carriers, food
dishes and other fomites are easily contaminated with this
virus. Since the virus particles can remain viable in the
environment for months, long after the infected bird is gone,
there is a high potential for widespread infection of an entire
flock of birds.
The first
clinically detectable sign of PBFD is the appearance of
necrotic, abnormally formed feathers. Many birds infected with
PBFD die with in 6-12 months of onset of clinical signs.
However, some birds have been known to survive 10-15 years and
become chronic carriers. Death usually occurs from secondary
bacterial, fungal, parasitic, chlamydial, or viral infections.
PBFD should
be suspected in any bird that shows progressive feather loss and
abnormal feather development. Molecular testing of the PBFD
virus is needed to rule out other disease processes that can
also result in abnormal feather development such as trauma,
bacterial or fungal infection of the feather follicles, other
viral infections, malnutrition, hormone problems, and adverse
drug reactions.
Routine
screening for PBFD virus should also be performed for any new
purchase or addition of birds to a flock since quite a number of
carriers have perfectly normal-looking feathers. It is still
unclear why some birds become carriers of the disease while
others do not. However, even if only one carrier is introduced
to a flock, the virus can rapidly spread and wipe out the entire
flock.
Until
recently, the primary method of diagnosing PBFD was the
demonstration of viral particles in the cells of the feather
follicle and/or shaft. This requires a surgical biopsy of the
affected feather and its associated follicle. Since PBFD virus
does not affect all feathers at the same time, this test could
give rise to a high false negative result due to sampling
variation. Molecular testing (Ypelaar et al., 1999) for the
virus in blood, a highly homogeneous source of sample,
significantly reduces the frequency of false negative results.
The high sensitivity and specificity of PCR detection also
enhance the successful screening of carriers, who may have very
low levels of the virus. Molecular testing requires only a small
amount of blood, rendering it less traumatic, especially for
small birds.
Any bird
testing positive for PBFD virus should be re-tested 90 days
after initial test and treatment. This is to help ensure that the
bird is not transforming into a chronic carrier. In addition,
since the virus survives in the environment, molecular testing
can also be used to test samples of feces and/or feather dust
taken from the surfaces in the environment so as to help stop the
spread of the disease.
Utilities:
-
Help confirm the disease causing agent
-
Environmental monitoring
-
Help ensure that bird populations are free of PBFD
-
Early prevention of spread of the virus among bird
populations
-
Minimize human exposure to the virus
-
Safety monitoring of biological products and vaccines
that derive from birds
References:
Ypelaar, I., Bassami, M.R., Wilcox, G.E. and Raidal, S.R. (1999)
A universal polymerase chain reaction for the detection of
psittacine beak and feather disease virus. Vet. Microbiol.
68:141-148.
Specimen requirements:
0.2 ml whole blood in EDTA (purple 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
fixed tissue.
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all
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.
Turnaround time:
2 business days
Methodology:
Qualitative real time PCR
Normal range:
Nondetected
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