BEIJING Shanghai's health authority has confirmed it is treating a man diagnosed with H7N9 bird flu, the third case of human infection in China this week.
The man traveled from the neighboring province of Jiangsu, the Shanghai Municipal Commission of Health and Family Planning said on its website on Wednesday.
Shanghai is China's largest city by population with more than 24 million residents.
Bird flu is most likely to strike in winter and spring and farmers have in recent years increased cleaning regimes, animal detention techniques, and built roofs to cover hen pens, among other steps, to prevent the disease.
(Reporting by Josephine Mason; Editing by Joseph Radford)