A senior World Health Organization (WHO) official warned in Kuala Lumpur, Malaysia, Wednesday that health workers should remain vigilant on severe acute respiratory syndrome (SARS) despite the number of probable SARS cases is declining in the world.

David Heymann, WHO executive director for communicable disease, urged scientists to continue case identification through surveillance.

"In the world today an infectious disease in one country is a threat to all: infectious diseases do not respect international borders," he said at a WHO global conference on the disease.

Infectious disease outbreaks reveal weaknesses in public health infrastructure, Heymann said.

However, he was quite confident that emerging infections can be contained with high-level government commitment and international collaboration if necessary.

Information and travel guidance can contain the international spread of an infectious disease, he added.

The WHO official said it is necessary to determine whether infection is endemic and seasonal, or whether it has disappeared from human populations.

Heymann also urged health workers to keep the global surveillance for influenza and other emerging infectious diseases.

The two-day WHO conference, which opened here on Tuesday, attracted some 1,000 scientists, medical workers and health officials.

(Xinhua News Agency June 18, 2003)