(Updates with poultry worker medical surveillance in fifth paragraph.)
Jan. 28 (Bloomberg) -- Hong Kong banned live chicken sales and will cull about 20,000 birds at a wholesale market after a sample imported from mainland China tested positive for the H7N9 avian influenza virus.
The 21-day halt of live-poultry sales comes two days before families traditionally hold feasts on the eve of the Lunar New Year. Shanghai is halting the sales of live poultry from the first day of the Chinese New Year, according to a Jan. 27 statement on the local government’s microblog.
Hong Kong is seeking to keep local cases of the disease from spreading via chickens arriving from China, which supplies most of the former colony’s food. The H7N9 strain of bird flu has infected 96 people in China this year, killing 19, the mainland’s official Xinhua News Agency reported yesterday, citing the Chinese Center for Disease Control & Prevention.
Hong Kong’s government will close the market for 21 days, until Feb. 18, for cleaning and disinfection and will suspend imports for the same period from the farm that provided the chicken, Secretary for Food and Health Ko Wing-man said in a Jan. 27 news release.
The poultry worker responsible for transporting the consignment of live chickens tested negative for the H7N9 virus in preliminary findings, according to a government statement. A total of 95 other contacts comprising 11 staff members of Man Kam To Animal Inspection Station, 35 poultry workers at Cheung Sha Wan Temporary Wholesale Poultry Market and 49 workers involved in the culling operation have also been identified as of 4 p.m. They were put under medical surveillance and health advice was given.
Human cases of H7N9 were first reported in China in March and spiked in April before agriculture authorities temporarily closed live poultry markets to limit human exposure. The disease can’t yet pass easily among people.
Even though H7N9 hasn’t mutated to become as contagious as seasonal flu, strains that emerge in China are of interest to researchers. The 1957-58 Asian Flu and 1968-69 Hong Kong Flu pandemics were first identified in the world’s most populous nation. Another bird-flu strain known as H5N1 is thought to have come from the southern province of Guangdong in 1996.
Human infections may rise further during Lunar New Year celebrations, when millions of people are expected to travel and households will slaughter poultry for festive meals, the Food and Agriculture Organization of the United Nations said Jan. 20. The Lunar New Year falls on Jan. 31 this year.
Laboratory experiments using ferrets -- the most common animal model for human flu infections -- have shown that the H7N9 virus is capable of spreading from person to person. Some small family clusters have been reported, though in December the World Health Organization said it hadn’t seen any evidence of sustainable human-to-human transmission.
H7N9 has turned up outside mainland China, in locations such as Hong Kong and Taiwan. It can circulate widely in chickens, ducks and geese without causing the mass die-offs characteristic of the better-known H5N1 virus. The germ is typically more active during the colder winter months, scientists have said.
Hong Kong will step up inspections as poultry accumulates at local producers because of the market closure, Ko said yesterday. The measures are part of the government’s contingency plan to stop the spread of the virus, and China’s central government will investigate to ensure mainland farms are following biosecurity measures, he said.
In 1997, the government ordered all poultry in Hong Kong to be culled. Many families in rural areas kept chickens in backyard wood-and-wire hutches that can still be seen lying empty and rusting in villages across the territory. Ducks, geese and pigeons are also widely eaten in Hong Kong.
The last time the government slaughtered and banned import of live poultry was in December 2011, after the deadly H5N1 bird flu virus was found in a chicken carcass at a wholesale market.
--With assistance from Eleni Himaras in Hong Kong. Editor: Andrew Davis