Bird flu now poses a bigger and more worrying threat to people than SARS, medical experts in southern China, the region where Severe Acute Respiratory Syndrome first surfaced, said on Friday.
The main reason, they said, was that humans had learned how to effectively control the spread of SARS, but had not done the same for bird flu, which can be spread by wild birds.
Bird flu has killed 62 people in Asia since 2003 and forced the slaughter of millions of fowl.
The World Health Organization has warned that bird flu has the potential to trigger a global pandemic if the virus mutates and becomes easily transmittable between humans.
“Bird flu has not been effectively contained. The threat of it mutating so people can transmit it is still there, and the threat is very large,” said Zhong Nanshan, one of China’s leading SARS experts.
“Bird flu is more dangerous” than SARS, he said in the southern city of Guangzhou.
SARS emerged in southern China, swept through the province of Guangdong, and spread globally in 2003, infecting 8,000 people and killing 800 of them.
Fears of a global outbreak of bird flu have grown since the deadly strain of bird flu, once largely confined to Asia, was found in eastern Russia and Kazakhstan.
It was not clear, however, if the strain was the H5N1 virus, which was found in several countries in Asia.
An outbreak of easily spread bird flu among humans could be disastrous, said Li Baojian, a professor at Zhongshan University who is involved in SARS medicine research.
“For human health and life it poses a big threat, and this threat affects global economic development, political stability. It is very acute and very frightening,” he told Reuters.
Experts have said southern China is the perfect breeding ground for new diseases, and a likely starting point for a long overdue flu pandemic because of the warm weather and the proximity in which animals and humans live.
The last major flu pandemic was in the late 1960s when some 4 million people died. Despite warnings, there were no major outbreaks of SARS last winter and Li said experts were still investigating why.
The initial outbreak was contained with quarantine and isolation. One theory is that that stopped the disease in its tracks, Li said.
Another is that the coronavirus that causes SARS mutated and may be carried by some people and animals without producing symptoms, he said. There have been cases of healthy people carrying the SARS antibodies.
