SHANGHAI, Jan 31 (Reuters) - A 21-year-old woman has caught the H5N1 strain of bird flu in central China's Hunan Province but is recovering in hospital, the official Xinhua news agency said on Saturday.

The farmer was found sick on Jan. 23 after coming into contact with birds that died of the disease, Xinhua quoted provincial health authorities as saying.

People who had close contact with the patient are under observation, but none of them has fallen ill so far. China has reported the case to the World Health Organization, Xinhua added.

On Monday, China said a young man had died of the H5N1 strain of bird flu in the southwestern region of Guangxi, the country's fifth reported death from the disease this month.

H5N1 remains largely a virus among birds, but experts fear it could mutate into a form that is easily transmitted by humans, which could kill millions of people worldwide.

Since the virus resurfaced in Asia in 2003 it has infected about 400 people worldwide and killed over 250 of them, according to WHO data released earlier this month. (Reporting by Andrew Torchia; editing by Elizabeth Piper)

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