Chinese authorities announced on Tuesday that they had begun destroying and vaccinating chickens in China’s eastern Jiangsu province after finding the deadly H5N1 strain of bird flu on a chicken farm in Dongtai city and in another farm in Haian county.

 

Experts say the possible outbreak could have been triggered by migratory birds. The virus had not been detected in any other locations.

More than 200 people have died across the world, with Indonesia accounting for one third of those deaths.

 

The discovery of infected birds in Hong Kong last week has determined the slaughter of more than 80,000 birds. Twenty countries had outbreaks of the disease during the first nine months of 2008, down from twenty-five during the same period in 2007, according to U.N. data. The outbreak is alarming because some of the chickens that were killed by the virus appear to have been vaccinated against it. Infectious disease experts say that Hong Kong uses an older version of the H5 vaccine than mainland China, where there are more frequent outbreaks and farmers vaccinate poultry specifically against the H5N1 strain of the virus.

 

Influenza A virus subtype, also known as H5N1, a subtype of the Influenza A virus, may mutate into a strain capable of efficient human-to-human transmission. A risk factor for getting the virus is handling of infected poultry. Infected birds transmit the virus though their saliva, nasal secretions and blood. Experts fear that the virus may cause more than one influenza pandemic as the virus is expected to continue mutating in birds regardless of whether humans develop immunity to a future pandemic strain. Studies indicate that these viruses continue to evolve, with changes in their internal gene aspects.