China denied on Jan. 29 a report by Britain's New Scientist that the avian flu began in the world's most populous nation, probably in the first half of 2003.
Facing allegations it was the source of the Asia-wide bird flu outbreak, China's Vice Agriculture Minister Qi Jingfa told reporters in Bankok: "It is purely a guess, a groundless guess."
"We have had very strict surveillance," Qi added.
The New Scientist, quoting unidentified health experts on Wednesday, said the outbreak "probably" began in China.
"A combination of official cover-up and questionable farming practices allowed it to turn into the epidemic now under way," the weekly magazine said.
A decision by China's poultry producers to vaccinate birds after an outbreak in Hong Kong in 1997 may have been a mistake and could have contributed to the problem, it said.
Hong Kong killed millions of chickens when the H5N1 bird flu killed six people. To protect its poultry, Chinese producers used an inactivated H5N1 virus after the outbreak.
"If the vaccine is not a good match for the virus -- as is the case with the H5N1 strain now sweeping Asia -- it can still replicate, but most animals do not show signs of the disease," the magazine said.
China earlier this week confirmed bird flu had been discovered at a duck farm in southern Guangxi Zhuang Automous Region near its border with Viet Nam.
Suspected cases of bird flu have also been detected in central China's Hubei and Hunan provinces.
Local officials said Wednesday two suspected outbreaks of the H5N1 strain of avian influenza had been confirmed in central China -- at a chicken and duck farm in Wugang in Hunan Province and a chicken farm at Wuxue in Hubei Province.
"Local veterinarians have basically confirmed it's bird flu," an official surnamed Jian at Wuxue livestock and animals bureau was quoted as saying.
Ministry of Agriculture officials are retesting samples in national laboratories, a ministry employee said, declining to confirm the two cases.
No human cases of bird flu, which has killed 10 people in Viet Nam and Thailand so far and spread to 10 Asian countries, have been reported yet in China.
The Chinese vice agriculture minister was in Bangkok to attend a conference on the bird flu crisis that pledged a joint fight against a virus which poses a serious threat to economies and public health in the region. Qi said he is confident the measures taken by the Chinese authorities will be able to control the disease.
Meanwhile Chinese President Hu Jintao and Premier Wen Jiabao ordered government officials at all levels to step up effective surveillance and do a good job in preventing the spread of bird flu.
"Once the epidemic is detected, strictly kill, fully disinfect, prevent the disease from spreading and guarantee people's health," their directive said.
China not source of bird flu outbreak: FM spokeswoman
Claims that China is the source of the southeast Asian bird flu outbreak are incorrect, unfounded, unscientific and therefore irresponsible, Chinese Foreign Ministry spokeswoman Zhang Qiyue said in Beijing on Jan. 29.
Avian influenza was a disease which humans had known about for 100 years, Zhang said. The sources and infection channels of the disease followed epidemiological patterns and required scientific study to understand.
To date, there had been absolutely no evidence that China was the source of the bird flu, she acknowledged, and China hoped all countries would take a scientific attitude towards the epidemic.
Officials from the World Health Organization (WHO) said earlier that it was too early to target any country as the source of disease, Zhang noted.
The Chinese government regarded the disease as a significant public health threat and public health had to be made a priority, she said. No Chinese had been inflected by the disease so far.
Zhang went on to say that the Chinese government had also taken a range of resolute legal and scientific measures to prevent and check its spread,
The government took comprehensive control measures from the very beginning, initiating a rigid reporting system as early as Jan. 19.
The Ministry of Agriculture and other relevant departments had informed all ports to strictly examine poultry from infected regions, and poultry from eight Asian nations had been banned.
Moreover, the government organized the production and storage of vaccines, dispatched at least nine groups to supervise and direct the prevention work, further improved laws and regulations to ensure the campaign was conducted legally, and beefed up cooperation with neighboring countries and international organizations and kept close contact with WHO and other relevant international bodies.
Only through international cooperation, could epidemics like bird flu would be eradicated, the spokeswoman said.