One confirmed case of A(H1N1) flu was reported in Beijing, the Ministry of Health said on Saturday evening.

It is the third confirmed case of A/H1N1 flu on the Chinese mainland, according to the ministry.

The case involved a 18-year-old female who studies in a university in the New York State of the United States, which was the one reported previously as suspected case by the Emergency Management Office of Beijing Municipal Government Saturday evening.

She was currently in a stable condition, with a normal body temperature, the ministry said.

The female, a Beijing native, arrived in Beijing on May 11 on board the US Continental Airline C089 and reached home accompanied by her mother, said the ministry.

She did not go out or meet friends after arriving home, according to the ministry's investigation.

She felt unwell and physically weak in the noon on May 12 and took her temperature herself.

She went to the fever outpatient section of the Peking University First Hospital in the evening on May 14 and said she developed symptoms of cough, a few sputum, headache, sore throat, chest distress and sore muscle, with a body temperature of 37.7 degrees Celsius.

She was initially diagnosed as fever, needing further check and "suspected of A/H1N1 flu," the ministry said.

The patient was transferred to the Beijing Ditan Hospital early in the morning on May 15.

The Beijing Center for Disease Control and Prevention (CDC) tested a specimen taken via a swab from her throat, which showed she was "suspected positive" for A/H1N1 and positive for PIV-H3.

The China CDC and the Chinese Academy of Medical Sciences tested the specimen again the next day and confirmed she had contracted the A(H1N1) virus.