WHO spokesman Bob Dietz reported that WHO had dispatched four teams to China.

He said that one team will help investigate the laboratories at the CDC, where it is believed that the infections originated. Another will join in the epidemiological investigations, while the third assists in ensuring that contamination control in hospitals is up to par and the fourth visits east China's Anhui Province.

The Ministry of Health reported no new confirmed or suspected cases of SARS in the 24 hours ending at 10:00 AM Tuesday. However, two people who had close contact with a SARS patient and are now under medical observation reported fevers.

Twelve others were removed from medical observation Tuesday.

The SARS patient in Beijing, surnamed Li, has been in relatively stable condition and has reported a normal temperature for 11 consecutive days, the ministry said.

Beijing's five suspected SARS patients were in Ditan Hospital for treatment and observation.

A total of about 700 people are now under quarantine in Beijing, according to Wu Jiang, of the Beijing Center for Disease Prevention and Control.

The increased number includes those who had contact with the two people who have now reported fevers, as well as those who had contact with the confirmed or suspected SARS patients.

The patient in Anhui, surnamed Song, is continuing to recover but her mother, who helped to care for her, died on April 19. The mother also had a heart condition.

A total of 146 people known to have had contact with Song were placed under medical observation, but 36 people have now been released.

In related news, Hong Kong took preventive actions against SARS on Monday. The Special Administrative Region's Secretary for Health, Welfare and Food Yeoh Eng-kiong called on government departments to raise their levels of alertness and preparedness.

The Health Department of Anhui has called on all laboratories to strengthen bio-safety practices and take steps to ensure the safety of laboratory workers.

Experts believe the epidemic might have been caused by a laboratory infection, since the Anhui patient and one of the suspected cases in Beijing worked in the same laboratory in March.

(China Daily April 28, 2004)