They were impressed with the work of the local government in Guangdong, south China, on the control of SARS (severe acute respiratory syndrome), said Breiman at press conference Saturday.

The hospitals they visited have done a remarkable job and they follow the procedures and techniques that are used by Asian countries to control the virus, according to the WHO expert.

The local government and hospitals have a job to protect medical staff and health workers, he said.

"We encourage scientists and medical experts here to release their huge amount of research results not only to China but also to international journals.

He hoped that local scientists and experts should pay special attention to the highly-infectious patients.

Talking about the origin of the virus, Breiman said, "We probably won't know for a while what the origin of this virus is."

"We can't really say without further information where this actually originated," he said, "It's really too early to tell where it came from."

"It's always possible it came from somewhere else, it's possible it came from here, we'll just have to wait for more information to come in," the expert said.

At this stage, their work is merely to collect data and analyze the data, Breiman said. "In fact, we don't know where is the origin of this virus," he added.

Alan Schnur, another WHO expert, said that for personal health, the risk is pretty. "If we compare the number of patients with the populations of Guangzhou and Hong Kong, the percentage is pretty small," he said.

"As to public health, the medical staff members and health workers are more likely to be infected by SARS. So we should take necessary and immediate measures to guarantee their safety." "There is risk, but it is pretty small. That's why we don't wear masks," he said.

The WHO delegation will stay in Guangdong until April 8.

(Xinhua News Agency April 6, 2003)