The three cases of H7N9 avian influenza infection are the first time the virus has been detected in humans, the National Health and Family Planning Commission said yesterday.
So far there is no vaccination for the virus, it said.
The men were an 87-year-old surnamed Li who took ill on February 19 and died on March 4, and a 27-year-old surnamed Wu who became ill on February 27 and died on March 10.
A 35-year-old woman surnamed Han from Chuzhou City in Anhui became ill on March 9 and is being treated in Nanjing, capital of Jiangsu Province.
All three showed initial symptoms of fever and coughing which developed into severe pneumonia with difficulty in breathing in later stages, according to the commission.
There was no sign that any of the three had contracted the disease from each other, and no sign of infection in the 88 people who had closest contact with them.
H7N9 bird flu is considered a low pathogenic strain that cannot easily be contracted by humans. The overwhelming majority of human deaths from bird flu have been caused by the more virulent H5N1, which decimated poultry stocks across Asia in 2003.
The World Health Organization is "closely monitoring the situation" in China, regional agency spokesman Timothy O'Leary told the Associated Press.
"There is apparently no evidence of human-to-human transmission, and transmission of the virus appears to be inefficient, therefore the risk to public health would appear to be low," O'Leary said.
The three cases were confirmed to be human infection with H7N9 avian influenza by a team of experts called in by the health commission.
On Friday, the Chinese Center for Disease Control and Prevention separated the virus from samples from the patients.
The commission said it was still unclear how the three got infected.
"So far, it is still an animal virus not a human virus," said Jiang Qingwu, dean of Public Health School of Fudan University.
Since only three cases of human infection of H7N9 have been found, relatively little research has been done on it. The expert team is working to study the toxicity and human-infection capacity of the virus, the commission said.
Yesterday, Shanghai Health Bureau said cases of flu and pneumonia in the city were normal for this time of the year. The 87-year-old's two sons have gone to hospital with similar symptoms.
According to Shanghai No. 5 People's Hospital, the three members of the Li family were admitted between February 14 and 24 for symptoms including a high fever and coughing. All three were diagnosed as having pneumonia. The 69-year-old son recovered and was discharged but the 55-year-old died from severe pneumonia and respiratory failure in late February. The father died of multi-organ failure.
Neither son had the H7N9 virus, the bureau said.
It has ordered local hospitals to step up monitoring and supervision on cases involving flu, pneumonia and other respiratory diseases.
Experts say there is no evidence to indicate the virus is spreading but patients with symptoms such as fever, coughing and breathing difficulties are being urged to visit their doctors, ensure good hygiene, such as by washing their hands, and avoid contact with diseased poultry and livestock.
http://www.shanghaidaily.com/nsp/Metro/2013/04/01/New%2Bbird%2Bflu%2Bstrain%2Bkills%2B2%2Bpatients%2Bin%2BShanghai/