A researcher from China's southern province where the SARS virus is believed to have originated said yesterday outbreaks of the disease might be sub-siding because people are developing antibodies after being exposed to the virus.
Zhong Nanshan from Guangdong Province made the comments during a video conference with Taiwanese doctors. Guangdong began seeing the world's first cases of severe acute respiratory disease last November.
The outbreak in Guangdong eased in mid-February after authorities enforced stringent quarantines and placed seriously ill patients in a better equipped hospital, said Zhong, who heads the Guangzhou Pulmonary Disease Research Institute.
But Zhong said many doctors and nurses who had cared for patients for weeks did not contract the illness, while staff from other hospitals that hadn't been exposed to the virus for long periods fell ill, he said.
Another crucial factor could be the climate, Zhong said.
Tests showed that the SARS virus was most active at 17 to 25 degrees Celsius, while it died at 50 degrees Celsius, he said.
This may explain why the outbreak peaked in subtropical Guangdong in early February, while Beijing, located in colder climes, had an outbreak only in April, he said.
It may also explain why SARS is more subdued in tropical Southeast Asia, he said.
Earlier this month, a University of Hong Kong microbiologist had predicted that there could be fewer SARS cases in Hong Kong in the summer, but that more people could get sick in the winter.
(eastday.com May 10, 2003)
