CHANGSHA, April 27 (Xinhua) -- Health authorities in central China´s Hunan Province on Saturday confirmed its first human infection case of H7N9 bird flu.

A 64-year-old woman surnamed Guan, a resident in Shaoyang City, started suffering from a fever on April 14, and laboratory tests confirmed her H7N9 infection on Saturday, Hunan Provincial Health Department said in a statement.

The statement said Guan had been exposed to poultry four days before she developed the fever. No abnormal symptoms had been found among the 41 people who were in close contact with the patient, it added.

An official with the department said Guan had been critically ill but that her condition was improving.