Rigorous management of live poultry markets is vital to controlling the risk of infection from the bird flu, scientists said recently.
"The H7N9 outbreak lineage has spread over a large geographic region and is prevalent in chickens at live poultry markets, which are thought to be the immediate source of human infections," according to an article published in the journal Nature on Aug 21.
The H7N9 bird flu virus, first detected in March, has infected more than 130 people in China and killed more than 40.
"Different kinds of poultry should be raised and sold separately in order to control the spread of H7N9," said Guan Yi, one of the authors of the article in Nature and a flu expert at the University of Hong Kong.
Guan led the international team in testing samples collected from chickens, ducks, geese, pigeons, partridges and quail in Wenzhou, Zhejiang province; Rizhao, Shandong province; and Shenzhen, Guangdong province.
"The live poultry market is a place where different flu viruses accumulate and combine genetically. It's better for people not to come close to live poultry," he said. "Sanitation of the live poultry market requires regular and careful efforts, instead of simply killing all the live poultry in the market when an epidemic breaks out."
In their published study, Guan and his team also found another H7-type virus lurking in chickens in China that can cause more severe pneumonia than H7N9. The new virus, dubbed H7N7, can infect mammals, including people, according to the study.
"The discovery shows that the H7 viruses detected by health authorities may not be limited to the subtype of H7N9," said Guan.