Southwest China's Sichuan Province reported two human H7N9 avian flu cases Tuesday, bringing the total number of infections in the province this year to six.
One of the patients is a 60-year-old man surnamed Huang, in Pengxi county, while the other is a 48-year-old woman surnamed Zhou, in Zhongjiang county. They are both in critical condition, according to the provincial health and family planning commission.
No symptoms were found among those in close contact with them. Local authorities have taken disease control measures.
Sichuan reported its first H7N9 case in early February.
H7N9 is a bird flu strain first reported to have infected humans in China in March 2013. Infections are most likely to strike in winter and spring.