H5 Bird Flu Confirmed in Sick Gosling on PEI Canada
Recombinomics Commentary
June 16, 2006
A case of H5 avian flu has been confirmed in a gosling by the Atlantic Veterinary College.
Dr. Lamont Sweet, P.E.I.'s chief health officer, said in a news release there is no evidence the virus can be transmitted by eating poultry products, but anyone in contact with poultry needs to take special care.
The sick gosling was from a flock of 20 geese and ducks kept in the backyard of a private home in O'Leary.
The above comments on a confirmed H5 infection in a sick gosling are cause for concern. Distinguishing high pathogenic avian influenza (HPAI) from low path (LPAI) is a relatively simple task. The HA cleavage site of HPAI has multiple basic amino acids, and the H5N1 of concern in Canada would be the Qinghai strain, migrating via the east Atlantic flyway. Virtually all Qinghai isolates have an HA cleavage site of GERRRKKR. This strain was initially identified at Qinghai Lake in May of 2005 and has since spread to southern Siberia, followed by migration to Europe, the Middle East, and Africa. The East Atlantic Flyway links northern Siberia, western Europe, western Africa, and northeast Canada. H5N1 in northeast Canada could then migrate to the south.
Recent sequences from Niger indicate the H5N1 there is distinct from the H5N1 in Nigeria, indicating the infections arrived via migratory birds. Other African countries in the eastern Atlantic flyway include Cameroon, and the Ivory Coast, where H5n1 has been detected. H5N1 has also been detected throughout western Europe (see phylogenetic tree), so migration into Canada this season is expected. Moreover, sequences from H5N1 in Astrakhan suggest H5N1 may have already been introduced into northern Canada last season.
Canada conducted tests on samples collected across southern Canada in August.. H5 was detected, including Prince Edward Island. The LPAI H5 was widespread, but the infected wild birds were healthy. Waterfowl can harbor H5N1 without evidence of illness.
The finding of a sick gosling is a concern, and may signal the appearance of HPAI H5N1. The announcement indicated H5 was confirmed, suggesting that the infection has already been somewhat categorized. Since the announcement did not say that the H5 was LPAI, it is more likely that it indeed is HPAI.
The sequence of the HA cleavage site would be definitive. GERRRKKR would indicate the Qinghai strain of H5N1 bird flu has been confirmed in North America.
Media Sources
Phylogentic Tree