Beijing: Two men from Shanghai have died after contracting the lesser-known H7N9 strain of avian influenza, while a third patient is in a critical condition, the Chinese government said today.
While two victims aged 87 and 27, were from Shanghai, the third patient is a 35-year-old female in Chuzhou City of nearby Anhui province.
China`s National Health and Family Planning Commission said that there was no evidence of human-to-human transmission of this type of avian influenza strain, which is commonly known as bird flu.
There was no sign that any of the three, who were infected over the past two months, had contracted the disease from each other, and no sign of infection in the 88 people who had closest contact with them, the medical agency said.
The patients showed initial symptoms of fever and coughs which developed into severe pneumonia and difficult breathing in later stages, state-run Xinhua news agency reported.
The cases were confirmed yesterday based on clinical observation, laboratory tests and epidemiological surveys by a team of experts summoned by the commission, the report said.
The Chinese Centre for Disease Control and Preservation collected samples of H7N9 virus from the patients two days ago.
The World Health Organisation has said it is "closely monitoring the situation" in China. "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," said regional agency spokesman Timothy O`Leary.
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.
However, as only three cases of human infection of H7N9 have been found, relatively little research has been done on it and there is no vaccine for H7N9 virus as yet.