It's not clear why there may be a difference in susceptibility between the genders, at least in the Southeast Asian city-state, which has imposed tough isolation and other measures to curb the illness.
On Friday, a Singapore court for the first time invoked tough new anti-SARS laws and imprisoned a man for six months for repeatedly flouting a home quarantine order. The man, who has since been cleared of any infection, was arrested when he went out drinking.
A government newspaper in Hong Kong claimed SARS originated in the U.S., not China, reports CBS News' Jeff Gibson. The article cited a Philadelphia woman who died of a strange flu-like virus early last year. But health experts like those from the World Health Organization still believe that the virus was spawned in China's southern Guangdong province, traditionally a petrie dish for the world's flu outbreaks.
A shortage of face masks in southern China has caused factories to stop production of women's bras and switch to making face masks. However, some residents are waiting for the changeover: They're using bras as face masks now.
Meanwhile, work by Singapore's Genome Institute, and published in Britain's The Lancet medical journal on Friday, indicates that the SARS virus is surprisingly stable and not rapidly mutating. This could challenge theories that it jumped from farm animals to humans not long before its first outbreak was reported in southern China in November.
It could also mean the virus is older than previously thought, said Earl Brown, a virologist at the University of Ottawa in Canada, who was not involved with the study. "Generally you'd see a virus mutate more when it first comes into a new situation," Brown said.
As the mystery over SARS origins and behavior deepened, the global toll climbed to at least 515 dead and more than 7,000 infected in over 25 countries on Friday.
Taiwan reported 18 new cases on infection, its largest one-day jump since the outbreak began there two months ago. Authorities feared it may have spread from capital Taipei to the island's south.
Hong Kong reported only two deaths and six new cases — the lowest daily infection increase so far.
"The trend continues to be very encouraging," said the territory's top political leader, Chief Executive Tung Chee-hwa, who has imposed strict quarantine rules and other tough measures. "We cannot let down our guard," he said.
China announced six more fatalities and 118 new hospitalizations.
Beijing accounted for two of the latest Chinese deaths as well as 48 new cases of infection. Earlier a senior official said new SARS hospital admissions had fallen from a peak of 70 to 80 per day last month to an average of 30 to 40 per day over the past week.
Malaysia reported its first new probable SARS case in two weeks on Friday, a day after health authorities declared that the worst of its outbreak was over. The patient is a 31-year-old hotel restaurant chef who recently worked in neighboring Singapore, officials said.
In Singapore, a study that analyzes its nine-week-long SARS outbreak, shows that while women in the city-state outnumbered men in contracting the illness, more than half of those who died were men.
The research, by the World Health Organization and Singapore's Health Ministry, said 66 percent of the island's probable SARS cases were women, but that 56 percent of the deaths were men. It did not explain the higher male death rate.
Those findings followed WHO's announcement on Thursday that the disease is far more deadly than it previously thought. The Geneva-based U.N. agency doubled its estimate for the global death rate to between 14 percent and 15 percent, with more than half of patients over 65 years old likely to die.
The Singapore study released Friday found on overall death rate of 12.5 percent.
In Manila, the Asian Development Bank counted the economic costs of SARS and cut its growth forecasts for Asia again. Hong Kong, Singapore and Taiwan would be the hardest hit, with growth in 2003 declining by 1.8 percentage points, 1.1 points and 0.9 points respectively, if the impact of SARS extends until the end of June, the bank said. That would lower annual growth rates to 0.8 percent, 1.9 percent and 2.8 percent for the three economies.
In an apparent sign of confidence in the battle against the disease in Beijing, authorities announced that college entrance tests for more than 80,000 are to take place June 7-8 as scheduled.
Officials may have feared that canceling the tests would provoke too much frustration in the city, following tough anti-SARS measures that have closed cinemas, gyms and other public facilities, and suspended classes at most universities.
"The upward tendency of SARS cases has been effectively checked in Beijing, and the epidemic shows signs of declining," Liang Wannian, deputy director-general of the city Health Bureau said at a news conference.
So far, SARS has mostly been an urban disease. But authorities in China still fear it might spread into the countryside, where the majority of China's 1.3 billion people live amid a shortage of doctors and hospitals unable to cope with epidemics.
In Hong Kong, where at least 210 have died of the disease, health officials were investigating an alleged coverup of a SARS outbreak at a private hospital, which failed to reported suspected SARS cases as required.