Commuters wearing face masks were seen on the streets and subways of major cities on Wednesday despite the early summer heat, saying they have grown more cautious of the A (H1N1) flu after seeing confirmed cases so close to home.

"The government is reacting quickly, but I'm still worried about the spread of the virus inside trains and planes," said a middle-aged woman Li, who wore a large face mask and dark sunglasses as she left a subway station in Beijing.

The mainland quarantined several hundred people yesterday who had been in contact with two Chinese men confirmed to have contracted the virus.

Sun Naiqing, a veteran Beijing cabbie, doesn't dare take passengers from the airport.

"I'd rather stay downtown, and I don't take passengers with masks and I don't turn on the air-con," he said at his wheel. "The scene of travelers wearing masks is scary."

Jia Peng, spokesman for the Beijing subway, downplayed worries for passengers yesterday and promised the metro will disinfect trains and keep the air inside carriages clean.

Lu, a 19-year-old overseas student who had contracted the virus, traveled from Canada to his hometown in Shandong Province and stayed at a crowded hotel before setting foot on several tourist sites, including the Great Wall and the bar district near Houhai in the capital.

Xu Fei, a middle-aged man in casual clothing and sandals, walked out of the tightly watched hotel where the infected student stayed on Wednesday, seemingly not worried about his lack of freedom. The friends who brought him bananas and French fries also believed the observation will end within a few days.

Mr Su, 50, arrived from a nearby residential building. He was told by disease control experts at the scene that the flu virus will not contaminate his neighborhood.

The public yesterday heatedly debated whether it was right for the 19-year-old man to expose potential victims to the virus.

"Now is the peak time for overseas students returning to China. They should be more thoughtful. I suggest a self-quarantine of a week," wrote "Maomao Donkey" on the popular Chinese forum Tianya.cn.

But Xue Lan, a public policy and management expert at Tsinghua University, said it is understandable for people to stick to their plans if they don't detect any symptoms.

"It is quite difficult for China, which takes in thousands of travelers from international cities, to keep the country free of the imported virus," he said. "We should just ask each traveler to be responsible and report to related personnel if they detect flu-related illness."

(China Daily May 14, 2009)