Authorities in eastern China announced a ban Tuesday on live poultry sales following a spike in the number of people infected with the H7N9 strain of bird flu, with the busy Chinese New Year travel period already under way.
So far this year, the virus has killed 20 people in China out of 96 known infections, according to the official Xinhua News Agency. The deaths were in eastern Shanghai, neighboring Zhejiang province and southern Guangdong province. A week ago, more than 50 cases had been reported. The virus remains hard to catch and most cases have been linked to contact with poultry.
The jump in cases comes during the 40-day travel period around Chinese New Year, a period that concerns health authorities because of the volume of people traveling in crowded trains and buses, often with live chickens aboard.
Chinese are expected to make 3.6 billion trips as families reunite. The holiday, which officially starts Friday, also falls during the winter months when flu typically rages.
Hong Kong on Monday suspended live chicken sales—halting imports from the mainland—for three weeks after poultry imported from the southern mainland province of Guangdong tested positive for the H7N9 virus, the first time the virus was found in imported poultry in Hong Kong.
On Tuesday, Hong Kong authorities were culling 20,000 birds, mostly chickens, at the territory's wholesale market, putting the birds into black plastic bags and pumping in carbon dioxide to suffocate them.
Live poultry trading will be halted in cities in coastal Zhejiang province from Feb. 15, where 49 people have been infected and 12 people have died this year, according to the Zhejiang Daily. From July, city poultry markets will be closed.
Neighboring Shanghai will halt live poultry trading for three months starting Friday. The city has reported eight infections and four deaths this year.
The World Health Organization says there is no evidence of sustained human-to-human transmission, but has recommended close monitoring given the holiday travel and the potentially unpredictable behavior of flu viruses.
Over the weekend, health authorities in eastern Jiangxi province confirmed a second human case of H10N8, a new strain of bird flu known to affect humans. They said the 55-year-old woman was in critical condition. The first case was confirmed in December after a 73-year-old woman died from the virus.
Explore further: China announces H7N9 bird flu deaths (Update)