It’s only a matter of time before H7N9 virus spreads beyond China, researchers warn
Zhuo zhongwei – Imaginechina/Associated Press
Chickens started the second wave of H7N9 bird flu that hit China last year, a new study concludes. With a third wave ongoing, pinpointing the source could highlight measures to prevent the disease from turning into a pandemic.
The virus spread from Zhejiang province in Eastern China southward, where it has evolved into at least three local varieties, researchers report online March 11 in Nature.
H7N9 avian influenza first became a concern in spring 2013 when it struck 136 people, killing about 40. The virus nearly disappeared during the summer only to reemerge in the fall. It sickened 318 people and killed more than 100 from October 2013 to September 2014. A third wave began last October. In total, more than 640 people have contracted the virus.
Researchers did not know why the virus bounced back so strongly. So Tommy Tsan-Yuk Lam of the University of Hong Kong and colleagues took samples from live