New find on SARS virulence

THE SARS virus is mutating at genetic “hot spots”, claims an international expert who suggests this may explain why some people get sicker than others from Severe Acute Respiratory Syndrome.

THE SARS virus is mutating at genetic “hot spots”, claims an international expert who suggests this may explain why some people get sicker than others from Severe Acute Respiratory Syndrome.Virologist Henry Niman of Harvard University yesterday reported evidence of several mutations in Coronavirus samples from mainland China and Hong Kong. The World Health Organisation has said Coronavirus causes SARS. “(This) may explain the virulent nature of the isolates (samples) that established SARS in Hanoi, Toronto, Singapore and possibly Hong Kong,” Dr Niman said on the International Society for Infectious Diseases website. Dominic Dwyer, a medical virologist with Westmead Hospital in Sydney, said: “It doesn’t surprise me there are hot spots.” But Dr Dwyer agreed with University of Western Australia microbiologist and virologist David Smith, who said it was too early to know just what the mutations meant. “We’re waiting for more information to see if the variation is altering its capacity to cause disease or changing the type of disease,” said Professor Smith. Meanwhile, the Department of Foreign Affairs and Trade yesterday lifted its advisory against Australians travelling to Toronto in keeping with the WHO lifting its travel ban. Some 23 people have died from SARS in Canada since a single sufferer fell ill after travelling from Hong Kong in late March. But the WHO lifted its travel advisory because the rate of SARS cases was on the decrease and three weeks had passed since the last case. However, Toronto was still listed as an “affected area”. Canada’s ambassador to Australia, Jean Fournier, told The Australian yesterday that Australians should know that the WHO had given Toronto “a clean bill of health” and it was “open for business and open to travellers”. Mr Fournier said the SARS outbreak had been unfortunate and could hit any country. He said Canada valued its trade, investment and tourism relationship with Australia. “There’s no doubt that SARS has done some damage . . . but more than 150,000 Australians visit Canada every year and we hope now they will continue to choose Canada as a holiday destination,” he said. DFAT has also heeded WHO advice that Vietnam has contained its SARS outbreak and has dropped its warning against non-essential travel. But the department has toughened its stance on travel to China after a further 200 SARS cases were reported yesterday. The new warning, on top of earlier advice that urged Australians to defer all non-essential travel, says Australians already in China should “consider whether their presence is essential”. Travellers have spread the virus to almost 30 countries, where nearly 6000 people have been infected and more than 390 have died in the past two months. (Source: The Australian, Leigh Dayton and John Kerin, May 02, 2003)