South Korea has H5N1 in poultry after 3-year lull

Nov 27, 2006 (CIDRAP News) – South Korea has reported its first outbreak of H5N1 avian influenza in nearly 3 years, on a poultry farm in North Jeolla province, about 100 miles from Seoul.

The virus was detected in dead poultry on a farm in the city of Iksan that raises parent stock for broiler chickens, according to a report that a South Korean livestock official filed Nov 22 with the World Organization for Animal Health (OIE). The report said the outbreak caused 6,500 deaths among 13,000 susceptible birds. The results were confirmed at the National Veterinary Research and Quarantine Service in Anyang.

The source of the outbreak is unknown, though Reuters reported that the farm lies on a bird migration route.

The last poultry outbreak in South Korea occurred in December 2003 and prompted the culling of 5 million birds. No human cases of H5N1 illness have ever been reported in the country, but South Korea's Center for Disease Control and Prevention said in September that five workers who helped cull poultry nearly 3 years ago showed evidence of past infection with H5N1 avian influenza, though they had not been ill.

According to a report today in the Korea Times, the South Korean agriculture ministry has begun culling 236,000 poultry on six Iksan poultry farms. A 3-kilometer quarantine zone was set up around the outbreak site, and a 10-kilometer surveillance zone covers 200 poultry farms in Iksan, Sochon, and Kumgang. Authorities have also banned the sale and shipment of poultry, eggs, and related products from the area and have set up checkpoints to inspect trucks.

Farms in the surveillance zone raise more than 50 million chickens and ducks, the Times reported.

Several media outlets reported today that South Korean health officials plan on culling cats, dogs, and other animals such as pigs in the area to control the spread of the disease. The Associated Press (AP) said South Korea culled dogs and cats along with 5.3 million birds during its last outbreak in 2003.

However, Peter Roeder, an animal health expert with the United Nations Food and Agriculture Organization (FAO), told the AP that he questions the validity of culling cats and dogs. "It's highly unusual, and it's not a science-based decision," he said. "We've got absolutely no reason to believe they're important."

Meanwhile, surveillance samples from apparently healthy birds on a farm 87 miles north of the outbreak site have tested positive for avian influenza, and more tests are being done to determine if the strain is highly pathogenic, according to another report today in the Korea Times. The virus was detected in a pair of chickens hatched from eggs purchased in mid November from a breeding farm in the Iksan area.

Ministry officials told the Times that the highly pathogenic virus is unlikely because there have been no mass chicken deaths on the farms.

Elsewhere, the H5N1 virus was detected in two turkeys that died in early November in Ivory Coast, according to an Agence France-Presse report last week. The turkeys came from a livestock camp at a village near Abidjan in the south. The country's last outbreak in poultry was in May.

Health officials told AFP that health and safety measures had been taken and that people who were exposed to the birds were under medical supervision.

See also:

Nov 23 OIE notice on H5N1 in poultry in South Korea
http://www.oie.int/Messages/061124KOR.htm

Sep 21 CIDRAP News article "Five Koreans had H5N1 virus but no illness"