NANJING, Feb. 10 (Xinhua) -- Twenty-one of the 49 people infected with H7N9 avian flu in January died in east China's Jiangsu Province, the provincial health and family planning commission announced on Friday.
In December, 14 of 54 people died from the virus.
H7N9 has entered its peak season, and direct contact with live poultry remains the main source of infection, said Bao Changjun with provincial center for disease control and prevention.
Cold weather provides the virus with a better environment and smog makes people vulnerable to infections, Bao added.
The public are advised to avoid direct contact with poultry and wear masks when symptoms such as headache, fever, coughing and chest congestion appear.
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.