The Ministry of Health confirmed a new human case of bird flu over the weekend.

A 19-year-old man surnamed Cheng, who is a soldier in the People's Liberation Army (PLA), is now receiving treatment at an army hospital, the ministry said on its website.

A spokesman for the ministry declined to say in which part of the country Cheng was stationed or how he may have come in contact with the virus.

Cheng developed a fever, cough and pneumonia on May 9. He was sent to an army hospital on May 14 and has remained there since then.

Tests by the local Center for Disease Control and Prevention (CDC) on May 18 showed that he had been infected with H5N1 strain of the bird flu virus. The result was confirmed by State and PLA CDCs last Wednesday.

The website did not indicate the status of Cheng's condition.

The ministry said leaders of the State Council and the Central Military Commission of the Communist Party of China were "highly concerned" by the case. They have ordered the army to cooperate with the local health bureau to closely monitor those who have had close contact with the patient. So far, none of them have shown symptoms of the disease.

The website said the Ministry of Health had conveyed the information to the World Health Organization, as well as health agencies in Hong Kong, Macao, Taiwan and several countries.

China has reported 25 human cases of bird flu since 2003, which have caused 15 deaths.

On March 27, a 16-year-old boy in eastern Anhui Province died from the deadly virus. The cause of his infection is still unknown.

The Ministry of Health confirmed last August that the country's first human case of H5N1 bird flu virus had occurred in November 2003. A 24-year-old man who died in Beijing in 2003 was initially thought to be suffering from SARS. Further laboratory tests later confirmed he had died of avian influenza.

The H5N1 bird flu virus is currently not very contagious, but experts fear it could mutate into a form that spreads easily among people, potentially sparking a pandemic.

Sinovac Biotech, a Beijing-based pharmaceutical company has been experimenting with a bird flu vaccine, and the State Food and Drug Administration approved in April a second phase of clinical trials.