Health authorities across Asia are on alert after a new case of Severe Acute Respiratory Syndrome emerged in Taiwan. The case is again raising concerns about infection control in medical laboratories in Asia.

Taiwan's Health Minister Chen Chien-jen announced a new case of Severe Acute Respiratory Syndrome Wednesday - just hours after the patient was diagnosed with the pneumonia-like disease. The patient is a researcher at a military-run medical laboratory and may have contracted the disease while studying the virus. All Taiwan laboratories researching SARS have been closed. This is the island's first case since July. But Mr. Chen says this viral infections so far appears isolated.

Within hours of the announcement, Hong Kong activated its SARS alert system. Health workers have been deployed to monitor incoming visitors from Taiwan.

Authorities in Singapore - where the man had traveled earlier this month to attend a medical conference - are tracing those who may have come into contact with the researcher. Singapore, Hong Kong, China, Taiwan, Vietnam and Toronto, Canada were heavily hit by SARS earlier this year.

SARS patients develop severe pneumonia. Early symptoms include high fever and difficulty breathing. The disease infected eight thousand people worldwide this year and killed more than 700 - before the outbreak was declared over in July. The Taiwan case is the second infection contracted in a laboratory since a Singapore researcher caught the virus in August. The World Health Organization has raised concerns over infection control in laboratories researching SARS.

Hong Kong's director of health, P.Y. Lam, says the territory's laboratories comply with WHO infection control guidelines. "The chances of laboratory workers contracting SARS, during work, are present. But I would say, low," he says. "All these precautionary measures are there to minimize the chances of this happening and if in case it happens, the chances of going out of laboratory will be kept to a minimum."

SARS first emerged in southern China in November last year. Experts have warned of a fresh outbreak with the onset of winter in the northern hemisphere. Several countries are developing vaccines for SARS but experts say it would take years before one would be widely available.