A Chinese medical expert has warned people to keep alert against Severe Acute Respiratory Syndrome (SARS) virus.

Han Demin, deputy director of Beijing health bureau, made the remark at a ceremony marking the discharge of the last two SARS patients on the Chinese mainland on Saturday.

An expert in ear-nose-throat surgery, Han said that although all SARS patients had been discharged from hospitals, the whole country must be vigilant against SARS virus because up to now, the sources of SARS virus and how people get infected have not been pinpointed.

"Currently, we're not quite sure about where and how SARS virus exists and whether the SARS disease will reoccur," Han said.

Han, also president of the Beijing Tongren Hospital, disclosed that Beijing has made full preparations to fight possible recurrence of SARS.

The preventive measures include the fact that Beijing has retained all fever departments in major hospitals and a contingent of medical workers specially engaged in prevention and treatment of SARS.

The city is also formulating an emergency plan to fight possible outbreak of SARS in future, Han said, adding the plan covers supply of medical materials and an emergency medical treatment system among others.

(Xinhua News Agency August 16, 2003)