Exposure to avian influenza H7N9 in farms and wet markets

In two studies describing clinico-epidemiological characteristics of H7N9-infected patients in China, 6 out of 7 patients had a history of exposure to market poultry.1,2 In Shanghai and Anhui, 20 of 280 specimens isolated from live market poultry were positive for H7N9, while none of 690 specimens isolated from farm poultry were positive.3 58% (34/59) of H7N9-infected patients had a history of visiting poultry markets.4 Although the importance of exposure to market poultry is acknowledged, exposure to farm poultry is a cause for concern, especially in rural China.