August 17, 2004

 

Thai Bird Flu Crisis Could Worsen In Wet Season

 

The Thai Livestock Development Department has increased surveillance of avian influenza following a report that three people in Vietnam had died of bird flu.

 

The department is concerned the second wave of the bird flu outbreak would become more aggressive as the air temperature falls during the rainy season.

 

"The renewed bird flu outbreak is under control, but we have to be on alert because outbreaks tend to get worse in the wet season, when the weather cools down," said department chief Yukol Limlamthong.

 

The outbreak had spread to 83 areas of 24 provinces as of yesterday.

 

Mr Yukol said the department had imposed a ban on poultry movements between Thailand and neighbouring countries, including Vietnam.

 

Vietnam's Ministry of Health told the World Health Organisation on Thursday that three recent deaths in the country from an influenza-like illness were caused by avian influenza.

 

These are the first officially reported fatal human cases of bird flu in the region since February.

 

"The confirmation of these cases underscores the risk of virus transmission to humans from infected poultry," the WHO said on Thursday.

 

"Of greatest concern is the risk that continuing transmission of the virus to humans will give avian and influenza viruses an opportunity to exchange genes, potentially giving rise to a new virus with pandemic potential," it said.

On the issue of vaccination, Mr Yukol said a technical committee would decide next month whether vaccines should be used.

 

Dr Wantanee Kalprawit, of Chulalongkorn University's faculty of veterinary science and a committee member, said a national manual on vaccination in chicken stocks was being drafted. The manual would be adopted if the government decided to use vaccination as an option to contain outbreaks.

 

Bird flu vaccination is prohibited by the government for fear that it could trigger virus mutation and eventually cause a human pandemic. Vaccination could also increase the risk of human infections because vaccinated poultry could become carriers. Moreover, Thai poultry products would be banned by major importers, including the European Union.

 

However, the government is under pressure from the poultry industry to revoke the ban and replace culling measures with vaccination.

 

Dr Wantanee said the decision on vaccination would be based on experiences in China, Indonesia, Italy, Mexico, and the United States.

 

She suggested bird flu vaccines be allowed in limited areas under strict supervision. A type of vaccine to be used in Thai poultry farms should be produced from the H5N1 virus strain, which has been found here.

 

But Dr Chanthanee Buranathai, animal disease expert of the Livestock Development Department, said using the same virus strain that exists in an affected country was prohibited under the international guideline because it would stop scientists differentiating vaccinated from non-vaccinated poultry.

 

"This will hurt the country's bird flu control operation," said Dr Chantanee.