CHANGSHA - A new human H7N9 avian flu case was reported in Central China's Hunan province Sunday, the 20th in the province this year.

The 69-year-old female patient, surnamed Zou, was diagnosed in Changsha city, the provincial capital. She had contact with poultry before falling ill and is in a critical condition, according to the provincial center for disease control and prevention.

This is the second H7N9 case in Changsha. Five of the the 20 patients in Hunan died from the virus.

H7N9 is a bird flu strain first reported to have infected humans in China in March 2013. It is most likely to strike in winter and spring.