Things you really should know about: bird flu

What is avian influenza?

Bird flu is a highly infectious viral disease caused by influenza A viruses, which normally infect birds and, less commonly, pigs. All birds are thought to be susceptible, but some species are more resistant than others. There are 16 H-types of influenza A, two of which affect birds—the H5 and H7 subtypes. The H5N1 subtype is responsible for the current outbreak.

What is the current situation?

The current outbreak emerged in poultry in South East Asia (in Korea) in December 2003 and has been documented as the most severe. The sudden spread of avian influenza in birds, with outbreaks occurring in numerous continents simultaneously, is historically unprecedented. Despite the extermination of more than 150 million birds worldwide, 176 human cases have been recorded in Vietnam, Thailand, China, Indonesia, Cambodia, Iraq, and Turkey by the World Health Organization. As of 10 March 2006, 97 people have died.

In Turkey, there have been 12 confirmed human cases, with four deaths. This has resulted in the Turkish government launching an intensive public awareness campaign.

Has an outbreak in humans ever happened before?

Avian influenza typically only affects birds and pigs, but has been known to infect humans. Human infection with the H5N1 subtype of avian influenza was first reported in Hong Kong in 1997, when 18 cases (six fatal) were identified. Ten human cases were then reported in Vietnam and Thailand in 2004, of which eight were …