HANGZHOU, Feb. 10 (Xinhua) -- Three men and a woman have been confirmed to have contracted the H7N9 bird flu in east China's Zhejiang Province, amid rising numbers of family-raised live poultry testing positive for the virus, local health authorities said on Monday.
The new cases bring the total number of human infections to 78 this year in one of the two provinces worst hit by H7N9, with the other being south China's Guangdong Province.
One of the three men infected is the first case reported in the city of Lishui, leaving only two of Zhejiang's 11 cities yet to report a human contraction of the virus.
The share of H7N9 patients with live poultry raised at home is on the rise as health authorities have found the rate of family-raised poultry, especially chicken, being tested positive for the virus stands between 30 and 50 percent in areas inhabited by H7N9 patients.
Authorities added that the virus has not yet been found in poultry farms.
"Family-raised poultry is likely to rise as another source transmitting the virus to humans after live poultry markets," said Li Lanjuan, an academician with the Chinese Academy of Engineering.
China has reported more than 120 human H7N9 cases this year, including at least 27 deaths. Medical experts have yet to find evidence pointing to human-to-human transmission of the bird flu virus.