The possibility that three people were infected by the bird flu virus in central China cannot be ruled out, the Ministry of Health said yesterday.

Of the three who came down with pneumonia last month in Hunan Province, one died.

A total of 192 people who had close contact with the three or dead poultry have been put under medical observation, with only one showing "acute bronchitis," the ministry said.

The ministry has sought the help of the World Health Organization (WHO) "as finding the exact cause of the pneumonia is dependent on further laboratory tests."

According to the ministry's spokesman, three people living in Xiangtan County where an outbreak of the deadly H5N1 virus strain among poultry was reported last month contracted pneumonia from unknown causes.

He Yin, a 12-year-old girl, died on October 17 of "infection in both lungs and acute respiratory distress syndrome (ARDS)," the spokesman said.

Her nine-year-old brother was also hospitalized with pneumonia-like symptoms but has since recovered.

The pair had close contact with sick birds, the spokesman said.

The third victim, who was only identified as Song, is a 36-year-old middle school teacher who had a minor injury on his hand while killing a chicken and later fell ill.

But his temperature returned to normal and his condition improved after being treated with antibiotics, the spokesman said.

All the three lived in or near Wantang, a village where the government said 545 chickens and ducks died of avian influenza last month.

The ministry initially reported that the girl and her brother tested negative for the H5N1 virus.

Roy Wadia, the WHO Beijing Office spokesman, said yesterday that his organization was part of the investigation.

"I don't think the ministry is trying to conceal the cases," Wadia said: "The cases occurred in a remote and isolated area, and the symptoms might be similar to many other diseases, so it's not easy to determine the reasons."

He said yesterday that it might take weeks, or even months, before the final test results are known.

Meanwhile, various authorities have announced a raft of measures to battle the disease.

Vice-Premier Hui Liangyu yesterday ordered all localities and departments to work harder to prevent the spread of the bird flu epidemic and any human infection of the virus.

The Chinese People's Liberation Army (PLA) has chalked out contingency plans to face any threat.

Anti-bird flu offices have to be set up at all levels of the army and they have to work closely with local agriculture and health departments.

Military hospitals have to isolate fever and respiratory-disease outpatients and prepare for possible human infections. Medicines and sanitized materials are being stockpiled.

An anti-bird flu research centre has been set up in Beijing to work on medical breakthroughs.

The centre, under the Institute of Biophysics of China Academy of Sciences, has roped in top scientists to work on prevention and treatment.

"Since the first breakout of the bird flu, we haven't figured out the nature of the virus and how it mutates from poultry to humans which is crucial," said Tang Hong, a researcher at the centre.

Scientists will also work on transgenic chickens, which will be immune to the bird flu virus.

In Northeast China's Liaoning Province, which last week reported the fourth outbreak of bird flu in the country, eight more villages have reported cases bringing the number of affected villages to 15.

Heishan County, in which all the 15 villages are located, is guarded by armed police and medical staff in bright anti-exposure suits. All vehicles entering the region must first be disinfected.

Poultry or eggs have been banned from local markets and in restaurants.

Beijing residents have to vaccinate all animals, including pets, against the bird flu virus and foot-and-mouth disease, according to a joint statement by the Beijing Agriculture Department and Public Security Bureau on Saturday.

Those who refuse to do so can be taken into custody or fined.

(China Daily November 7, 2005)