Bird flu virus in humans mutating

BEIJING, Nov. 29 (Xinhuanet) -- The H5N1 strain of bird flu seen in human cases in China has mutated as compared with strains found in human cases in Vietnam.

Doctors examine the chest X-ray results of an infant suffering from bird flu. The H5N1 strain of bird flu seen in human cases in China has mutated as compared with strains found in human cases in Vietnam.[AFP/file]

Chinese labs have found that the genetic order of the H5N1 virus seen in humans infected in China is different from that found in humans in Vietnam, Xinhua news agency reported Monday.

In China's human cases, the virus has mutated "to a certain degree," health ministry spokesman Mao Qun'an was quoted as saying.

"But the mutation cannot cause human-to-human transmission of the avian flu," he noted.

Mao said since the H5N1 bird flu first broke out in 1997, most human cases have been reported in Hong Kong, Thailand, Vietnam, Cambodia, Indonesia and the Chinese mainland. No human case has been found in Europe so far.

The major channels of human infection involve direct contact with infected poultry or their secretion and excretion, as well as inhalation of the particles of the virus from the poultry's secretion and excretion, said Mao, noting that the general public won't get infected if they keep themselves away from sick and dead poultry.

By Nov. 25, the World Health Organization (WHO) had reported 132 laboratory-confirmed human cases of bird flu including 68 deaths.

China this month confirmed its first three human cases of bird flu, two of which were fatal. The disease has killed more than 60 people in Asia since 2003.

Health officials fear that the virus could mutate to the extent where it is easily transmitted from human-to-human, an event that could lead to a global pandemic capable of killing hundreds of millions of people