A patient in Frankfurt has been diagnosed with Severe Acute Respiratory Syndrome (SARS), a lung disease that has affected more than 200 people and caused at least 9 deaths in recent weeks, primarily in Asia. The Frankfurt case is the first known instance of the disease in Europe, and since its discovery, European airports have stepped up precautions to prevent its further spread.

A 32-year-old doctor from Singapore, the Frankfurt patient had direct contact with two SARS patients from Hong Kong earlier this month, then traveled with his wife and mother-in-law to New York to attend a conference. He experienced a sudden fever and pains during his flight home via Frankfurt Saturday (March 15). The doctor and his mother-in-law, who also showed symptoms that may be linked to the disease, were immediately brought to an isolation ward at the Frankfurt University Hospital. Their fellow passengers were temporarily quarantined, and the Singapore Airlines jet they were traveling on was disinfected under police surveillance and returned to Singapore.

Physicians treating the man say he has shown all the characteristic symptoms of SARS, which include fever, muscle pains, hoarseness, coughing and difficulty breathing, according to the World Health Organization (WHO). "We are certain that that's what it is," says Hans-Reinhard Brodt, director of the Frankfurt isolation ward. Both the man and his mother-in-law, whose case has not been confirmed, showed signs of improvement on Tuesday. The doctor's wife, 30, who began exhibiting symptoms on Monday, is also under treatment.

Under the guidance of the WHO Global Outbreak Alert and Response Network, scientists in 10 countries are working together to identify the agent that causes the disease. Investigators in Germany and Hong Kong say it may belong to the paramyxovirus family of microbes, related to the source of mumps and measles. "We know that paramyxoviruses can cause lung diseases," explains Frankfurt virologist Hans-Wilhelm Doerr. Researchers still don't know for certain, he stressed, "but we have picked up on some clues."