H7 In South Korea
Recombinomics Commentary
November 26, 2007
On a customary condition of anonymity citing office policy, a ministry official said that quarantine workers have slaughtered about 17 thousand ducks at a farm in Gwangju, about 330 kilometers southwest of Seoul. The official added the virus that caused the latest outbreak is the H7 type that is “low pathogenic” and does not spread to humans.
The ministry official noted that the latest outbreak does not affect South Korea's status as bird flu-free country as it involves a “low pathogenic” virus.
The above comments describe a new H7 outbreak in South Korea. Outbreaks at this time of year in South Korea are expected. Last year outbreaks involved both low and high path avian influenza. The high path was clade 2.2 (Qinghai) H5N1, and new outbreaks are expected this season.
In late 2003 South Korea reported H5N1 in the same general region. The H5N1 subsequently spread to Japan and was a precursor of the Qinghai strain. Last year Qinghai H5N1 was isolated in South Korea at the end of the year, followed by a Qinghai H5N1 in Japan in early 2007.
The location in western South Korea maps to migration routes from Mongolia. Recent reports of H5N1 in Pakistan, Saudi Arabia, Egypt, Krasnodar, and England suggests similar outbreaks will be reported in South Korea and Japan in the next several weeks.
The presence of H7 and H5 in the same area is cause for concern. H7 is readily transmitted to humans, the above comments not withstanding. The transmission is efficient for both low and high path H7. A recent H7N2 outbreak in England was low path, but the number of infected people was almost as high as the number of infected birds. Usually the human H7 infections are relatively mild, but recombination between H7 and H5 could lead to more efficient transmission of a more lethal virus.
Media Links
Recombinomics Presentations
Recombinomics Publications
Recombinomics Paper at Nature Precedings