According to the Hunan provincial disease control and prevention centre, she had contact with poultry before falling ill and is in critical condition.

People who had close contact with the patient have not shown symptoms of fever or coughing.

In addition to Hunan, human H7N9 infections have also been reported in the provinces of Guangdong, Guizhou, Hubei, Henan, Jiangxi and Shandong, as well as in Shanghai, Hong Kong and Macao.

Report says H7N9 is a bird flu strain first reported to have infected humans in March 2013 in China.

It is most likely to strike in winter and spring.