Organ Damage Raises H5N1 Concerns in Canada
Recombinomics Commentary
June 20, 2006
Four of 11 geese died Monday. A post-mortem examination of the bird was inconclusive, said Clark, who noted a number of diseases could have caused the organ damage seen.
The above comments do not appear to rule out high pathogenic avian influenza as the cause of the organ damage in one of the geese that died June 5. Thus, the comments add to the data indicating the Prince Edward Island geese deaths were due to the Qinghai strain of H5N1.
Initial testing confirmed that H5 infected the four geese that died after displaying symptoms on June 4. Symptoms, followed by waterfowl death are hallmarks of the Qinghai strain of H5N1. Low pathogenic H5 isolates do not usually kill waterfowl. Frequently, only a drop in egg production is noted.
The above comments on organ damage are in marked contrast to the OIE description of an H5 positive duck in British Columbia in 2005. That infection was from a low path H5N2 and the description of autopsy results indicated there was no evidence of active infectious disease
The suspect bird was a 40-day-old meat duck collected at processing. The bird was in excellent body condition with submitting criteria of dermatitis. No other visible lesions and no indication of any active disease process were observed on post-mortem examination.
Thus, there were four geese that had symptoms of H5N1 infection on Prince Edward Island. One of the birds was tested and was positive for H5 and the autopsy identified organ damage consistent with an H5N1 infection.
News is expected today or tomorrow from the National Labs in Winnipeg. Sequence data is expected, which will determine if the H5N1 cleavage site is present and additional sequence data can easily distinguish between North America and Qinghai polymorphisms.
At this time, the released information clearly points toward the H5N1 Qinghai strain of bird flu.
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