Beijing  - A two-year-old girl has been infected with bird fly and is in a critical condition in China's northern Shanxi province, a health official of the provincial government confirmed Sunday, according to a report by the Chinese Xinhua news agency.

The girl is the second person infected with the H5N1 bird flu virus within a month in China.

Her health had deteriorated after she first fell ill on January 7, and she had been taken to the Shanxi hospital following initial treatment in a different hospital.

Medical tests by the Chinese Center for Disease Control and Prevention confirmed that she was infected with the H5N1 strain of avian influenza.

The people she had been in close contact with were under medical observation, but nobody had been found ill so far, the official said.

In early January, a young woman died of the virus in Beijing, the first bird flu fatality in the country in just under a year.

Experts fear that the virus could mutate to infect people not only via the consumption of poultry but by human-to-human contact, a development that could lead to a worldwide pandemic.

Since the illness resurfaced in 2003, 393 have been confirmed as infected with bird flu world-wide, of whom 248 died. China has officially reported 32 infections and 21 fatalities. dpa