Vietnam reports new H5N1 outbreaks in poultry

Dec 20, 2006 (CIDRAP News) – Vietnam's first major outbreaks of H5N1 avian influenza since last year struck two poultry farms in the southern Mekong Delta recently, government officials reported yesterday.

Vietnamese veterinary officers filed reports on the outbreaks yesterday with the World Organization for Animal Health (OIE). One in Ca Mau province began Dec 6, killing 2,523 unvaccinated chickens and duck chicks. Another in Bac Lieu province began Dec 7 and killed 3,550 unvaccinated 1-month-old ducks.

The reports to the OIE said 2,400 poultry had been culled on the two farms and that the source of the infection was unknown.

Hoang Van Nam, deputy director of the Department of Animal Health, told the Associated Press (AP) yesterday that the risk of the virus spreading in the area was high because farmers had dumped dead ducklings into canals.

In a Bloomberg News report today, Nam faulted farmers for not reporting the poultry deaths sooner and said local animal health officials and farmers had neglected to maintain the poultry vaccination program in the area. "They thought the disease had gone away," he said. Deutsche Presse-Argentur reported yesterday that the birds had not been vaccinated because they were hatched illegally.

The country has been one of the hardest hit by avian flu; it has had the highest number of human cases, 93, and had the most human fatalities until August, when Indonesia took the lead. Widespread poultry outbreaks prompted the culling of 66 million birds to prevent the spread of the virus.

However, in 2005 the country became the first to institute mandatory nationwide poultry vaccination. No new human cases have been reported since November 2005, and before the recent outbreaks, reports of infected poultry had slowed to a trickle.

International experts have held Vietnam up as a model for its aggressive avian flu prevention efforts, which also include banning poultry rearing and live-market sales in urban areas, restricting commercially raised ducks and quail, strictly controlling poultry transport within the country, and compensating farmers for culled birds.

Experts probe South Korea outbreaks
Elsewhere in Asia, a 9-member crisis management team from the OIE and the United Nations Food and Agriculture Organization (FAO) is on a 10-day mission to South Korea to investigate the H5N1 outbreaks in poultry that occurred south of Seoul in late November.

The mission is the first full-scale deployment of the FAO-OIE crisis management team since it was launched in mid-October at FAO headquarters in Rome, according an FAO press release yesterday. The trip is scheduled to end tomorrow.

The Korean government invited the team to evaluate the risk of further disease spread in South Korea, according to the FAO. The team includes international and Korean veterinary epidemiologists, wildlife veterinarians, biologists, and poultry specialists. They will be looking for any wild bird deaths on affected farms or adjacent wetlands and collecting environmental samples.

The FAO said if time allows, the team will also investigate other disease angles, such as how dead birds, eggs, and manure are handled and the role that fencing, cages, vehicles, and water might have played as sources of infection.

Bird deaths raise fears
In other developments, recent bird deaths in Idaho, France, and Russia raised fears of avian flu, but media reports said the disease was ruled out in all three instances.

In Idaho last week, 2,000 mallard ducks found dead along a creek in the southeastern part of the state died of an infection after they ate moldy grain, Reuters reported on Dec 15. Paul Slota, a wildlife expert at the US Geological Survey's National Wildlife Health Center in Madison, Wis., told Reuters that the ducks probably died of the fungal infection aspergillosis and that further testing is planned.

At a farm in eastern France, 4,000 chickens died suddenly on Dec 16, raising avian flu fears. However, the AP reported yesterday that the French agriculture ministry determined that the cause of death was asphyxiation due to a malfunctioning ventilator.

In St Petersburg, Russia, the deaths of two geese prompted the closure of a zoo, according to a Reuters report yesterday. Russian sanitary expert Gennady Onishchenko told Interfax news agency that samples taken from the geese tested negative for avian flu. Reuters said the zoo would remain closed until the end of the year.

See also:

OIE notification reports on H5N1 poultry outbreaks in Vietnam

Oct 25 CIDRAP News special report "Vietnam's success against avian flu may offer blueprint for others"

Dec 19 FAO press release on deployment of crisis management team