The Ministry of Health said on Sunday that the cause of a disease diagnosed as pneumonia in three people in a county that saw an outbreak of avian influenza was uncertain. One of those affected, a 12-year old girl, died three weeks ago.

"After conducting comprehensive analysis, experts said although the three cases are diagnosed as pneumonia of unknown causes at present, the possibility of human infection of the highly deadly H5N1 strain of bird flu cannot be ruled out," a ministry spokesperson said.

"We still need further tests in the laboratory to find the exact causes," he said, adding that a Chinese Center for Disease Control and Prevention lab is carrying out tests and that the ministry has invited WHO experts to help ascertain the cause of the disease.

Twelve-year-old He Yin in Wantang Village, Shebu Township of Xiangtan County, Hunan Province was hospitalized on the morning of October 16 with "serious pneumonia" at the Xiangtan Maternal and Childcare Hospital and transferred to Hunan Childrens' Hospital at noon.

She died the next morning and tested negative both to the H5N1 bird flu and SARS viruses, according to the spokesperson.

Her nine-year-old brother was hospitalized on October 17 at the Xiangtan Maternal and Childcare Hospital and on the evening of the following day transferred to Hunan Childrens' Hospital to receive treatment in isolation.

From October 22, his body temperature returned to normal, as did the results of clinical examinations.

He was suspected of being positive to H5 bird flu in one test, but negative in all other tests relating to the H5N1 strain. He also tested negative to SARS.

A 36-year-old male teacher named Song was also admitted to Xiangtan Traditional Chinese Medicine Hospital after being diagnosed with pneumonia on October 24. After receiving antibiotics, his body temperature returned to normal and his condition stabilized and improved. He tested negative both to the H5N1 virus and SARS.

According to the spokesperson, the ministry reported the cases of the two children to the WHO on October 28, and reported in detail on all three cases and prevention and control measures on November 3.

Wantang saw one of four recent Chinese outbreaks of bird flu in poultry, with the deaths of 545 chickens and ducks reported to the World Organisation for Animal Health on October 25, along with the culling of 2,487 and vaccination of 43,750 other birds.

(Xinhua News Agency November 7, 2005)