CHANGSHA -- Central China's Hunan province Thursday reported another human H7N9 avian flu case, bringing the total number of infections in the province to 17 this year.

The male patient, 67, was diagnosed in Hengyang City. He had contact with poultry before falling ill and is in critical condition, according to the Hunan provincial disease control and prevention center.

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

Hunan has reported 17 human H7N9 infections, including five fatalities, this year.

In addition to Hunan, human 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.

An early onset of this year's human H7N9 virus, which is more active this winter, has resulted in more infections in Hunan and the whole country, according to Liu Fuqiang, an official with the Hunan disease control and prevention center.

The public are advised to avoid direct contact with poultry and wear masks when symptoms such as headache, fever, coughing and chest congestion appear.

At least ten people have died from the virus since the start of the year, according to disease control centers in Henan, Guangdong and Hunan provinces.

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.