Four more human H7N9 cases

China reported four more human H7N9 virus infections on Thursday.

A 19-year-old man in central China's Hunan province was confirmed on Wednesday to have contracted the virus, bringing the total to 9 in the province.

South China's Guangdong province also reported three more cases on Thursday, including an 8-year-old boy, a 46-year-old man and a 65-year-old man.

So far China has reported more than 120 human H7N9 cases this year, including at least 31 deaths.