SHANGHAI (REUTERS) - A man in China's central Henan province has become the latest person reported to have died this winter from H7N9 bird flu, the state news agency Xinhua said on Saturday (Jan 14) citing local health authorities.

The 36-year-old roast duck salesman developed a fever and a cough around Dec 25 in coastal Zhejiang province, near Shanghai, and returned to Henan in early January, Xinhua said. He was diagnosed with H7N9 on Jan 10 and died the next day.

Bird flu is most likely to strike in winter and spring. In recent years, farmers have stepped up cleaning regimes, animal detention techniques, and built roofs to cover hen pens, in their efforts to prevent the disease.

China's last major outbreak killed 36 people and caused more than US$6 billion (S$8.6 billion) in losses for the agricultural sector.

The H7N9 strain does not seem to transmit easily among people, and sustained human-to-human infection has not been reported, the World Health Organization says.

The danger is that any such virus mutates and acquires genetic changes that could boost its pandemic potential.