Bird flu (avian influenza)
While we sniffle our way through winter, we are not alone. Birds can also be affected by various strains of bird ‘flu. The avian influenza (AI) virus generally causes mild disease in birds, but some strains cause death. Such strains are called highly pathogenic avian influenza (HPAI) or fowl plague.
Over the last few years, one of these fatal strains, called H5N1, devastated chicken and other poultry flocks in some parts of Asia. The outbreak hit countries such as Thailand and Vietnam hardest, as they rely on chickens for food and export.
Cambodia, Indonesia, Japan, China, South Korea, the Philippines, Europe and the United Kingdom have all reported cases of H5N1 virus infection. Japan and South Korea have been able to control these outbreaks quickly and safely.
The strain has also infected some people who have had close contact with sick birds, and has led to numerous human deaths in Thailand and Vietnam. Scientists are concerned that the virus could mutate and gain the ability to transmit from one person to another as easily as a normal ‘flu virus, which could lead to a global pandemic .
The H5N1 strain has been detected in migratory geese, which means that the disease could be spread when the birds travel during change of seasons. The World Health Organization (WHO) predicts that India could be at greatest risk from these birds. The WHO is also encouraging changes to farming practices and marketing of live animals, to reduce the risk of the H5N1 strain to humans.
In 2005, initial clinical trials showed that an experimental H5N1 vaccine evoked an immune response in humans. Several different H5N1 vaccines are currently under development around the world. Once a safe vaccine is available, the WHO plans on creating a global stockpile of up to 50 million doses.
Any researchers studying the H5N1 virus wear special biocontainment suits to prevent infection, and work in certified biocontainment laborator ies with strict controls against infection.
For updates about avian influenza go to:
Poultry news: http://www.thepoultrysite.com
New Scientist: http://www.newscientist.com/channel/health/bird-flu
The World Health Organization: http://www.who.int/csr/disease/avian_influenza/en/