The Chinese National Health and Family Planning Commission has reported 13 additional human cases of avian influenza A(H7N9) with onset of symptoms between February 14 and March 21.
The patients comprise nine men and four women aged 32 to 80 and three of them (two men and one woman) died. Ten cases are from Zhejiang, two are from Fujian and one is from Shandong.
To date, 633 cases of human H7N9 infection have been reported by the Mainland health authorities cumulatively since 2013. In the third wave since November 2014, 193 cases have been reported in the Mainland, including 72 cases in Guangdong (see attachment for geographical distribution), 39 cases in Fujian, 38 cases in Zhejiang, 17 cases in Jiangsu, seven cases in Xinjiang Uygur Autonomous Region, seven cases in Anhui, six cases in Shanghai, two cases in Hunan, two cases in Jiangxi, two cases in Shandong and one case in Guizhou.
Influenza A H7 viruses are a group of influenza viruses that normally circulate among birds. The avian influenza A(H7N9) virus is one subgroup among the larger group of H7 viruses. Patients with this infection have had severe pneumonia.
Symptoms include fever, cough and shortness of breath. However, information is still limited about the full spectrum of disease that infection with avian influenza A(H7N9) virus might cause.
People mainly become infected with avian influenza through close contact with infected birds and poultry (live or dead) or their droppings. Human-to-human transmission is inefficient.