International health officials say the Chinese government has said little about an unidentified illness that has killed hundreds of hogs in southern China. VOA's Luis Ramirez reports from Beijing.

Chinese girl looks into pig pen (file)

It was only after newspapers in Hong Kong reported the illness that the official media in mainland China mentioned the outbreak. Residents in southern China's Guangdong province say the disease, which apparently leads the animals to bleed to death, broke out as early as February, and has spread to more than 1,000 pigs. information about the disease secret for months, until it spread across the border to Hong Kong, and on to other parts of Asia.

Guo Fusheng is a technical adviser at the United Nations' Food and Agriculture Organization office in Beijing. He said his agency is still awaiting word on the pig illness from the Chinese authorities.

"We discussed with the Ministry of Agriculture. They said they are going to (issue) a declaration. We got very limited information from them," he said.

Newspaper accounts speak of hundreds of pigs bleeding to death in Guangdong. News reports in southern China Tuesday said the government had ordered pig breeders to vaccinate their stocks, even though officials have yet to identify what is causing the disease.

Reports have quoted local residents as saying the mystery disease has killed as much as 80 percent of the hogs in the Gaoyao and Yunfu areas of Guangdong province. A newspaper quotes a local official as saying that figure is not true.

International health officials are monitoring the outbreak, since diseases seen in pigs can sometimes jump to people.

The World Health Organization has criticized the Chinese leadership for failing to hand over tissue samples in a timely manner of people and poultry infected with the H5N1 bird flu virus. The WHO was also critical of Beijing's hesitation in providing full information about the SARS outbreak.