H5N1 in Central South Korea
Recombinomics Commentary
January 19, 2007
A new highly-virulent bird flu case has broken out in central South Korea, despite wide-ranging quarantine efforts, government officials said Saturday.
"Breeding chickens in a poultry farm in Cheonan turned out to be infected with a highly-virulent strain of avian influenza," the Ministry of Agriculture and Forestry said in a statement.
"The farm is a concentrated breeding area where quarantine efforts have been made on an elevated scale after avian influenza was found there in Jan. 2004," it said.
The above comments provide additional evidence for a replay of the 2003/2004 explosion of H5N1 in Asia. In December, 2003, H5N1 was reported in South Korea. That was followed by outbreaks in January in Japan and additional locations in South Korea, which has been repeated in 2006/2007.
The 2003/2004 H5N1 in South Korea and Japan were closely related to each other, and were precursors of the Qinghai strain, first identified at Qinghai Lake in May of 2005.
The 2006 outbreaks coincided with whooper swan migration from Mongolia to South Korea. Whooper swans infected with the Qinghai strain were first reported in Mongolia in 2005. The outbreak in late 2006 in South Korea has been cited as the Qinghai strain. Japan has noted the rapid death of experimental chickens by the H5N1 from the current outbreak. Rapid death in experimental chickens is another characteristic of the Qinghai strain.
It is highly likely that the H5N1 in Japan, as well as the new outbreak in South Korea, will be the Qinghai strain.
Unlike 2003/2004, H5N1 is no longer confined to Chian and countries to the south and east. The Qinghai strain migrated to the west and was reported for the first time in 2005/2006 in Europe, the Middle East and Africa. The first human cases linked to the Qinghai strain were confirmed in January, 2006 in Turkey, and there ios a current outbreak in Egypt.
This season all five human cases in Egypt have died and today a Ministry of Health spokesperson indicate there were five new suspect cases. Two of the cases in Egypt have a Tamiflu resistance polymorphism, N294S, which has never been reported previously in H5N1 cases in the absence of the common Tamiflu resistance polymorphism, H274Y. N294S has been identified in ducks, and waterfowl is the likely source of the N294S in the two patients in the Nile Delta.
Additional cases in Indonesia as well as suspect cases in Thailand suggest new cases in birds and patients will be announced in the upcoming days.
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