Senior citizens in China's commercial capital of Shanghai are taking preventive steps against the spread of a new virus, monitoring their health, staying indoors to reduce exposure, and even giving up meat.

Authorities say the coronavirus, which has killed 17 and infected nearly 600 people since it first emerged late last year, originated from illegally traded wildlife at an animal market in the central city of Wuhan.

With hundreds of millions of Chinese gearing up for travel during Lunar New Year holidays that begin on Saturday, officials fearing an accelerated spread of the virus have imposed a lockdown on Wuhan.

"I think this new year is going to be less festive," said a 70-year-old man who stood outside a bustling clinic in Shanghai, wearing a mask and waiting to see a doctor because he had felt feverish the previous night.

"It's better to be safe and this way I won't affect other people," said the man, who gave only his surname, Xia, as he pulled down his mask in order to smoke.

"I'm trying to smoke less too," he laughed as he looked at his cigarette.

Immune systems weakening with age are seen as making the elderly more susceptible to infections and diseases, and most virus victims have been older than 60 or suffered pre-existing conditions. The youngest was a 48-year-old woman.

Another elderly resident of Shanghai said she was avoiding crowded places or areas with animals.

"I go straight to where I need to go, and then I go home," said 79-year-old Li Meihua, from behind a mask. "My nose is a bit runny already. I'm also maintaining a cleaner diet, I've turned vegetarian now."

At a Taiwan vegetarian restaurant located beside a Buddhist temple, since some Buddhists follow a vegetarian diet, a waitress said it had drawn some new diners since the outbreak.

"Some told me they come to have vegetarian food, as it's cleaner and healthier," she told Reuters. "But it's not too busy now, people have left the city as New Year is coming soon."