The findings of the study indicate that the mean prevalence of
circovirus was quite high with 190 samples identified as positive
from a total of 421 samples. Among the different species tested,
African Grey Parrots (58.33%) showed high prevalence followed by
Cockatoos (34.42%), Macaws (25.53%) and Parakeets (16.6%). The
high prevalence in African Grey Parrots could be due to the large
number of samples of these birds submitted for analysis (Table 1).
Unfortunately,tracing the origin ofthe infected birds and the origin
of the infection proved to be difficult. It was therefore not possible
to indicate if the birds were infected on arrival or got infected in
the bird markets where hygiene standards are questionable.
Captivebreedingprograms carriedoutinAustralian wildspecies
of parrots have shown that the disease has the potential to spread
rapidly among captive birds (http://www.environment.gov.au).
Based on our categorization of imported and captive birds, we tried
to see if this holds true with our results. In 2011, a high proportion
of captive birds (69 birds) were tested, of which 43 (41.4%)
were found to be positive for circovirus (Table 2). Whether these
birds get infected with the newly added imported birds that are
carriers of the disease or whether they are naturally infected is not
known. Though an assumption can be made in concurrence with
the Australian study that this high positivity may be due to the
rapid spread of infection in the farm, it needs to be supported by
more such observations and data on captive birds. Unfortunately,
enough samples were not received from captive birds during the
other years to get significant ratios.
The number of imported birds received for testing seemed to
steadily increase over the years with the highest number (128
birds) being tested in 2014. Of these, 66 (51.56%) birds were positive.
The other years also showed a good number of circovirus
positive birds.
Combined statistical results (T-test) suggest that there is no significant
difference in the incidence of circovirus between imported
and captive birds (Table 2). This, however, could be affected by lack
of clear differentiation of the two groups.
Sequencing of circovirus isolates from three different psittacine
species was performed to see if there were any significant differences
in the PBFD virus that could point to the high positive
viral sequence obtained from the other four African Grey Parrots is
similar to the sequences obtained from Macaw and Cockatoo samples,
the difference seen may be attributed to the origin of the virus
and not the species. More work needs to be done to elucidate this.
The study warrants thoroughscreening of all birds before import
and only circovirus free birds should be allowed to enter the UAE
with extra vigilance on birds coming from countries where the
disease is endemic.
It is worth mentioning that it is imperative not only to test
psittacine birds for PBFD when they are sick, but also when they are
purchased. Awareness about the severity and spread of the disease
should also be created among private owners and farm managers
so they can manage small outbreaks. A more extensive surveillance
approach should be adopted to prevent any major outbreak of this
debilitating disease in the future. Also, as a future goal, additional
screening needs to be done in species other than psittacine birds
to provide conclusive results about the actual prevalence of the
disease in the region.
The findings of the study indicate that the mean prevalence ofcircovirus was quite high with 190 samples identified as positivefrom a total of 421 samples. Among the different species tested,African Grey Parrots (58.33%) showed high prevalence followed byCockatoos (34.42%), Macaws (25.53%) and Parakeets (16.6%). Thehigh prevalence in African Grey Parrots could be due to the largenumber of samples of these birds submitted for analysis (Table 1).Unfortunately,tracing the origin ofthe infected birds and the originof the infection proved to be difficult. It was therefore not possibleto indicate if the birds were infected on arrival or got infected inthe bird markets where hygiene standards are questionable.Captivebreedingprograms carriedoutinAustralian wildspeciesof parrots have shown that the disease has the potential to spreadrapidly among captive birds (http://www.environment.gov.au).Based on our categorization of imported and captive birds, we triedto see if this holds true with our results. In 2011, a high proportionof captive birds (69 birds) were tested, of which 43 (41.4%)were found to be positive for circovirus (Table 2). Whether thesebirds get infected with the newly added imported birds that arecarriers of the disease or whether they are naturally infected is notknown. Though an assumption can be made in concurrence withthe Australian study that this high positivity may be due to therapid spread of infection in the farm, it needs to be supported bymore such observations and data on captive birds. Unfortunately,enough samples were not received from captive birds during theother years to get significant ratios.The number of imported birds received for testing seemed tosteadily increase over the years with the highest number (128birds) being tested in 2014. Of these, 66 (51.56%) birds were positive.The other years also showed a good number of circoviruspositive birds.Combined statistical results (T-test) suggest that there is no significantdifference in the incidence of circovirus between importedand captive birds (Table 2). This, however, could be affected by lackof clear differentiation of the two groups.Sequencing of circovirus isolates from three different psittacinespecies was performed to see if there were any significant differencesin the PBFD virus that could point to the high positiveviral sequence obtained from the other four African Grey Parrots issimilar to the sequences obtained from Macaw and Cockatoo samples,the difference seen may be attributed to the origin of the virusand not the species. More work needs to be done to elucidate this.The study warrants thoroughscreening of all birds before importand only circovirus free birds should be allowed to enter the UAEwith extra vigilance on birds coming from countries where thedisease is endemic.It is worth mentioning that it is imperative not only to testpsittacine birds for PBFD when they are sick, but also when they arepurchased. Awareness about the severity and spread of the diseaseshould also be created among private owners and farm managersso they can manage small outbreaks. A more extensive surveillanceapproach should be adopted to prevent any major outbreak of thisdebilitating disease in the future. Also, as a future goal, additionalscreening needs to be done in species other than psittacine birdsto provide conclusive results about the actual prevalence of thedisease in the region.
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