Vaccinating poultry against avian flu is contributing to spread

Inappropriate use of vaccination in poultry to try to prevent the spread of bird flu has become part of the problem and has serious human health implications, officials of the World Health Organization warned this week.

“Vaccination can sometimes cause silent transmission of infection from asymptomatic birds. Mass vaccination programmes entail people tramping around the countryside from farm to farm and they can spread the disease with them. The first response must be culling,” said Peter Cordingley, WHO's spokesman in Manila.

Figure 1.

Following two human deaths from avian flu, China has said that it intends to vaccinate all its four billion chickens

Credit: AFP/GETTY

Although no vaccine has yet been approved for use in humans, birds have been vaccinated against the disease for about four years. The Chinese government has said that it intends to vaccinate all its four billion chickens. The Indonesian government has said that it did not have the resources to control the outbreak by culling because it could not afford to compensate farmers.

China's announcement on mass vaccination of birds came in the same week that its Ministry of Health confirmed the country's first two human cases of H5N1 avian flu, one of them fatal. Two new confirmed human cases, both fatal, have also been reported in Indonesia. A 20 year old woman and a 16 year old girl died in early November in Jakarta, taking the country's death toll to seven out of 11 confirmed cases.

China's announcement has triggered a heightened state of alert in neighbouring Hong Kong, which has reintroduced temperature checks on all travellers at border points into the city, which were instituted during the 2003 outbreak of severe acute respiratory syndrome (SARS).

The two confirmed human cases of bird flu in China are in a 24 year old woman farmer from Anhui province who was hospitalised with severe pneumonia on 7 November and died three days later and a nine year old boy from a village in Hunan province, which has been afflicted with avian flu in poultry.

He has since recovered but his 12 year old sister died after being hospitalised, also for severe pneumonia. She was cremated before adequate samples could be taken to make a diagnosis.

The Chinese government had previously denied that the two children had contracted avian flu but later requested the help of the World Health Organization to investigate the deaths. The Chinese Centre for Disease Control and Prevention's laboratory in Beijing did tests, and a team of experts from WHO that visited the laboratory confirmed the results.