The deadly bird-flu virus has re-emerged in Phitsanulok where more than 2,000 fowl have been culled, a Livestock Development Department senior official said yesterday.

The department's Disease Control and Veterinary Service Bureau chief Nirandorn Uangtrakoonsuk confirmed labo-ratory tests showed at least two ducks died of the virus in Plai Chumphon.

"We conducted lab tests after we received reports ducks had died en masse," he said. The cull was car-ried out last Friday.

Nirandorn said the area would be watched closely for the next 30 days. Prior to these infections Thailand had been clear of the virus for 160 days.

The Public Health Ministry's Department of Disease Control is monitoring the province and Suphan Buri.

"Infections in birds in Suphan Buri and ducks in Phitsanulok are warning signs for us to X-ray [for the virus] to the maximum extent," department head Dr Thawat Suntrajarn said.

January to February was a critical period for possible re-emergence of the virus and the department was on high alert in 36 provinces, he said.

"We're waiting for the livestock department to confirm if bird deaths in the two provinces were caused by the flu virus," said Thawat. To prevent illness and death from a new wave of bird flu the department may declare red zones in provinces previously affected by flu.

"We're in the 60 dangerous days," he said, adding that surveillance measures would be beefed up during this period.

Bureau of Epidemiology head Dr Kumnuan Ungchusak said disease-control units in Phitsanulok have visited areas where people had flu-like symptoms or reports of poultry deaths - since late December.

Thawat and Kumnuan said no people had tested positive yet for the flu.

Kumnuan said this was the peri-od of highest risk because cool weather made it easier for the virus - believed to be endemic in the country - to spread.

In addition, Chinese New Year celebrations next month will see large numbers of poultry slaugh-tered and transported.

The persistent spread of bird flu in neighbouring countries like Indonesia increased the chances of the virus re-emerging here, Thawat said.

Last week, China reported a human bird-flu fatality. That coun-try has not reported an outbreak since 2005.

Arthit Khwankhom,

Manatchai Ananta

The Nation