Researchers in protective suits test samples of a suspected case of the H7N9 avian influenza virus at the provincial center for disease control and prevention in Hangzhou, capital of east China's Zhejiang Province, April 17, 2013. An emergent testing team on 24-hour stand-by was set up in the center after the recent spread of the H7N9 virus. Infections within the province will be officially confirmed by the center. (Xinhua/Xu Yu)
