The university came up with the findings after setting up a multi-disciplinary team that has been analyzing the genetic fingerprint of the Severe Acute Respiratory Syndrome (SARS)-coronavirus from eleven patients.

"Through this investigation, the team has obtained scientific evidence which demonstrates that the virus is mutating at a rapid rate. A change in the genetic signature of the virus is demonstrable even between the passage of the virus from one wave of infection to the next," a press release issued by the university said.

Speaking at a news conference Friday, Stephen Tsui, associate professor of the Department of Microbiology at the Chinese University of Hong Kong cited a recent case where mutation of the virus and change of its toxicity took place within a mere two-week period within a person.

"For example, a particular medical worker was infected two weeks after a certain patient was. And when we look at his (the medical worker's) genetic fingerprint, we found that it was changed already in only two weeks. So the speed of evolution of this virus is high," Tsui said.

The study also revealed the presence of SARS-coronavirus that is unrelated to the different genetic signatures derived from the one involved in the Prince of Wales Hospital outbreak, indicating that there is more than one SARS-coronavirus types are present in Hong Kong, it said. Tsui added that the different patterns of genetic fingerprints are pointers showing the various places of infection of individual patients.

"From Nethersole hospital, we found two patients, who were totally unrelated to the patient from the Metropole Hotel in Hong Kong. When we examined their coronaviruses, we found that in one of the two from Nethersole hospital, the genetic fingerprint is different from those we came across before, meaning that the place of infection is central and meaning that the fingerprint can point to the source of the infection," Tsui said.

By comparing these new data with virus sequences reported from other parts of the world, a model for the evolution of the virus has been postulated, and such a model will serve to predict genetic signatures, the press release said, adding that the search of this viral ancestor would shed more light on the origin of SARS,the press release said.

Members of the multi-disciplinary SARS research team that undertook the ongoing research comprise more than 30 academic and research staff from the Department of Biochemistry, Department of Chemical Pathology, Department of Medicine and Therapeutics, Department of Surgery and Department of Microbiology.

(People's Daily May 3, 2003)