H5N1 Confirmed On Second South Korean Farm
Recombinomics Commentary
November 28 2006
Bird flu killed about 200 chickens at a South Korean farm, the second outbreak of the H5N1 avian influenza strain in three days, fueling concerns that the virus may be spreading in the country again after three years.
The farm, in the southwestern city of Iksan, housed about 12,000 fowl about 3 kilometers (1.9 miles) from a farm where an H5N1 outbreak was confirmed Nov. 25, Kim Yang Il, a spokesman at South Korea's agriculture ministry, said over the phone today.
The infections are the first in South Korea, Asia's second- biggest corn importer, since an initial H5N1 outbreak in December 2003.
The above comments confirm a second outbreak of HPAI H5N1 in South Korea. The case is outside the 500 meter cull zone, so a new perimeter is being established for the second farm. However, the location of these farms in a migratory bird flyway raises additional concerns that the infections are linked to wild birds. Larger numbers of chicken deaths have been reported in three or four locations other than the two confirmed farms, although media reports indicate those infections are not H5N1. The media in Korea has adopted a new definition of avian influenza, which excludes all serotypes other than H5N1, so media reports that birds are avian influenza negative may be false.
The H5N1 positive farms mimic the outbreak in December of 2003 that was followed by H5N1 infections in early 2004 in Japan as well as countries throughout eastern Asia, including human fatalities in Vietnam and Thailand.
Although it is three years later, the H5N1 surveillance worldwide has moved beyond scandalous. The current outbreak in South Korea came without warning. South Korea has never reported H5N1 in wild birds, even though the Qinghai strain has significant regions of identity with H5N1 from South Korea/Japan 2003/2004 isolates. Similarly, Japan detected H5N1 in local wild birds in association with the 2004 outbreak on farms, but has not reported H5N1 in any migratory birds or detection of any Qinghai isolates.
Similarly, the number of public Qinghai isolates from eastern Asia remains at one. The Shantou isolate was among the 404 HA sequences collected in southeastern China in 2005 and 2006.
In Europe, 700 samples positive for the Qinghai strain have been identified, but almost all samples are from dead wild birds and farm infections. Detection of H5N1 in live birds has been close to zero. The country that has detected H5N1 in live birds has been Russia, but these positives came after widespread infections were identified on farms.
In North America, testing of dead or dying wild birds has been minimal. In the United States, fewer than 1000 birds have been tested, even though 35,000 live or hunter killed birds have been tested. Although low path H5N1 has been detected and isolated in the live birds, no H5N1 has been identified in the small number of tested dead or dying birds. The failure to detect low path H5N1 in these birds defines a fatally flawed surveillance system, which actively ignores the large wild bird die-offs, frequently in areas where H5N1 has been detected in live birds.
Similarly, no H5N1 has been reported in wild birds in Indonesia. Moreover, human H5N1 has not matched H5N1 from poultry, yet testing of humans in Indonesia is largely limited to patients who have a link to dead or dying poultry.
Recent reports on the outbreak in Turkey have highlighted he large number of false negatives, which is increased by testing samples from patients after they have been given Tamiflu.
The surveillance failures are worldwide and leave gaping holes in H5N1 monitoring. These holes create major gaps in the H5N1 sequence database. The holes are increased by the hoarding of sequences by the major WHO consultants who have thousands of H5N1 sequences on their hard drives and/or the WHO password protected database.
Media sources
Phylogenetic Trees