H7N9 bird flu patients prepare to leave the First Affiliated Hospital of the Medicine College of the Zhejiang University, in Hangzhou, capital of east China's Zhejiang Province, May 3, 2013. A total of ten H7N9 bird flu patients in Hangzhou were discharged from the hospital on Friday following treatment. (Xinhua/Yang Xiaoxuan)

H7N9 bird flu patients who have recovered meet press at the First Affiliated Hospital of the Medicine College of the Zhejiang University, in Hangzhou, capital of east China's Zhejiang Province, May 3, 2013. A total of ten H7N9 bird flu patients in Hangzhou were discharged from the hospital on Friday following treatment. (Xinhua/Yang Xiaoxuan)

H7N9 bird flu patients who have recovered meet press at the First Affiliated Hospital of the Medicine College of the Zhejiang University, in Hangzhou, capital of east China's Zhejiang Province, May 3, 2013. A total of ten H7N9 bird flu patients in Hangzhou were discharged from the hospital on Friday following treatment. (Xinhua/Yang Xiaoxuan)

A H7N9 bird flu patient surnamed Cao meets press after his recovery at the First Affiliated Hospital of the Medicine College of the Zhejiang University, in Hangzhou, capital of east China's Zhejiang Province, May 3, 2013. A total of ten H7N9 bird flu patients in Hangzhou were discharged from the hospital on Friday following treatment. (Xinhua/Yang Xiaoxuan)