Jul 28, 2006 (CIDRAP News) – Laos has reported its first major outbreak of H5N1 avian influenza in more than 2 years, on a poultry farm in an area bordering part of Thailand that has recently been hit by the disease.

A United Nations Food and Agriculture Organization (FAO) official said the disease surfaced on a farm just south of the capital city of Vientiane and killed 2,500 chickens, news services reported today. Reuters said the H5 subtype was first detected on Jul 18. The Thai National Institute of Animal Health later confirmed that the virus was H5N1, according to a Bloomberg News report.

The last poultry outbreak in Laos occurred in January 2004, according to the World Organization for Animal Health (OIE), though the virus was reported to have infected a single backyard duck in May of this year. Reuters reported today that the same farm was the site of the latest outbreak and the one in 2004. Laos has not reported any human cases or deaths.

The Laotian government culled all chickens on the farm, disinfected the area, and restricted movement of livestock within a 5-kilometer surveillance zone, Wantanee Kalpravidh, FAO regional coordinator for avian influenza projects in Bangkok, told reporters.

The international community has been helping Laos—a primarily rural country of 5 million people—establish a strategy to fight avian flu, according to the news reports. The United States contributed $3.4 million in October, Reuters said.

Meanwhile, across the border in Thailand, the Bangkok Post reported today that H5N1 avian flu may have infected five more people in two provinces that the government has declared bird flu "red zones." The public health ministry said the new cases increased the number of suspected cases to 44, with lab results awaited in all of them, the Post said.

Three of the latest patients are from Phitsanulok province and were hospitalized Jul 26. All experienced flu symptoms and had contact with chickens in areas with poultry outbreaks. In Phichit province, a 42-year-old woman and a 4-year-old girl from two different districts became ill after they touched chicken carcasses at their homes.

The recent re-emergence of H5N1 avian flu in Thailand followed an 8-month hiatus. The virus killed a 17-year-old boy in Phichit province earlier this week and has been confirmed in birds there. Besides Phichit and Phitsanulok, five other north-central Thai provinces are on the list of avian flu alert zones: Sukhothai, Uttaradit, Suphan Buri, Kanchanaburi, and Nakhon Pathom.