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Rapid Mutation of SARS Virus Could Complicate Diagnosis
Associated Press
BEIJING -- There has been a fivefold increase in SARS deaths in the past month and the virus that causes the flu-like illness is mutating rapidly, which could complicate efforts to develop a solid diagnosis and a vaccine, researchers said Friday.
Twenty-four new deaths were reported Friday in east Asia, pushing the death toll to 418, up from 78 just four weeks ago. Eleven of the deaths were in China and eight in Hong Kong.
In Taiwan, which had five new fatalities, lawmakers passed legislation Friday allowing for prison sentences of up to three years for people who knowingly infect others with severe acute respiratory syndrome. They also set up a billion-dollar fund to tackle the disease.
Officials in Singapore sought to quash rumors that people of Indian descent are immune to SARS, or that drinking alcohol, smoking cigarettes and abstaining from pork can help ward off the flu-like illness.
Dr. Dennis Lo, at the Chinese University of Hong Kong, where doctors have completed genetic sequencing on virus samples from 11 SARS patients, said that by late March there were two forms of SARS present in hard-hit Hong Kong.
"This rapid evolution is like that of a murderer who is trying to change his fingerprints or even his appearance to try to escape detection," said Dr. Lo, adding that this could complicate efforts to diagnose SARS and develop a vaccine.
But he added that more work needs to be done before researchers can say whether the virus has become more infectious and lethal, and other researchers cautioned it was too soon to say for certain whether the SARS virus was mutating.
The World Health Organization says outbreaks of severe acute respiratory syndrome appear to have peaked in most places other than China, where more than 100 new cases of infection have recently been reported daily in Beijing alone. The WHO on Friday removed the U.S. and Britain from the list of countries affected by the SARS virus.
An "affected area" is defined as a country where the virus has spread within local communities in the last 20 days, double the incubation period for severe acute respiratory syndrome. Vietnam was declared free of the SARS virus on Monday. The remaining countries on the "affected" list are Canada, China, Singapore and Mongolia.
Authorities said they had no idea when Beijing's infection rate might subside. To ease some pressure on the city's dramatically overloaded health system, medical workers in white anti-infection suits moved patients into a 1,000-bed SARS isolation facility hastily built on Beijing's outskirts.
Ambulances with flashing blue lights dropped off the sick, then drove through a pool of disinfectant as they departed. The complex of one-story prefab buildings, surrounded by a high brick wall next to an ostrich farm, was built in eight days by 7,000 laborers working around the clock.
At least 91 people have died of SARS and more than 1,640 have been sickened in Beijing, which has shut down schools for 1.7 million students, and closed cinemas, karaoke bars and other entertainment places.
Frightened Chinese villages have erected barriers and posted guards to protect their communities from possible SARS carriers. Millions of Chinese have obeyed government orders to stay home during current May Day holidays.
On Friday, officials said only healthy Beijing university students could go on vacation to their hometowns and that they must not travel to known SARS-affected areas and also must stay away from underdeveloped rural areas and China's west, which lack a strong health care system.
In Hong Kong, health officials said some patients released from hospitals after they were thought to have recovered continue to carry the SARS virus, and some have suffered relapses.
Hong Kong health director Dr. Margaret Chan urged all recovered patients to be meticulous about hygiene. "We warn them not to have close contact with family members, like no kissing, no hugging," said Dr. Joseph Sung, head of the Department of Medicine at the Chinese University of Hong Kong.
Doctors there say traces of the virus have been found in the urine and excrement of some people thought to have recovered, although there is no evidence of the disease having been spread by them.
One big outbreak in Hong Kong, at the Amoy Gardens apartment complex, is believed to have been spread partly through leaking sewage pipes, but involved people who were clearly sick with SARS.
University of Hong Kong microbiologist Yuen Kwok-yung said the virus thought to cause SARS could enter a lull during warm-weather months then pick up again in the winter. Any such outbreak could be catastrophic in crowded Hong Kong if everyone is not "super-clean," he said in a radio interview. "If this new virus behaves like the two previous coronaviruses that were transmissible among humans, we have reasons to believe that we might have to a gasp for breath in summer," he said.
There is no cure for SARS, which carries symptoms including fever, body ache, dry coughing and shortness of breath. But most patients recover with prompt hospital care.
In a development that could quicken the search for ways to diagnose and cure the virus, American and Canadian experts announced they had reviewed and authenticated two nearly identical sequences of the SARS virus genetic structure. The publication of the virus genome, which is being rushed into print by the prestigious Science journal, should help researchers find drugs to treat the deadly respiratory illness and to develop a vaccine to prevent the infection, experts said.
Copyright (c) 2003 The Associated Press
Updated May 2, 2003 10:33 p.m.
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