Bird Flu

Bird flu, also known as avian influenza, is an infection by avian influenza viruses, which are transmitted from wild birds to domesticated birds, and from domesticated birds to human beings.

This infection was first reported in 1997 in Hong Kong, then reemerged in 2003 in southeast Asia and spread across Asia, the Middle East, Africa, and Europe. Since its emergence, it has infected about 249 people and killed 180 worldwide, with the most deaths in 2005 and 2006. It caused panic at a global level and mobilized scientific and medical experts as well as politicians and lay people.

The term human influenza virus usually refers to the subtypes that spread widely among humans. There are only three known A subtypes of influenza viruses (H1N1, H1N2, and H3N2) currently circulating among humans. It is likely that some genetic parts of current human influenza A viruses originally came from birds. Bird flu is caued by the influenza A(H5N1) virus, or the H5N1 virus, which occurs mainly in birds.

Medical researchers found that most human cases have resulted from people having close contact with poultry infected with the H5N1 virus or H5N1-con-taminated surfaces.

When the first confirmed cases of human infection from several subtypes of avian influenza were reported in Hong Kong in 1997, there were 18 patients, six of whom died. The disease reemerged in China's Fujian Province in 2003, with two human patients, one of whom died. It also appeared in Vietnam in three human patients, all of whom died.

In late 2003 and early 2004, more outbreaks of avian influenza were detected in eight countries: Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam. Mass killings of infected birds [Page 243]began in order to control the outbreaks; more than 100 million birds in the affected countries either died from the disease or were killed to limit its spread. By March 2004, the outbreak was reported to be under control. New outbreaks of bird flu among poultry and wild birds occurred in Asia in June 2004, and for the same year the World Health Organization (WHO) reported 46 cases in Thailand and Vietnam of humans infected with bird flu, 32 of whom died. In 2005 and 2006, following the wild birds’ migration routes, the disease quickly spread to the birds of Asia and central Asia (Indonesia, Russia, Kazakhstan, and Azerbaijan), the Middle East (Turkey and Iraq), Africa (Djibouti) and Europe (Greece, Italy, France, Germany, and the United Kingdom [UK]). This also led to an increase in cases of bird flu among humans, mostly in Indonesia, Thailand and Vietnam.

When wild birds have close contact with domesticated birds, such as chicken, ducks, and turkeys, avian influenza can be easily spread to the domesticated birds and can make them very sick and kill them in a short period of time.

Avian influenza viruses occur naturally among birds, and wild birds worldwide carry the viruses in their intestines without getting sick from them. However, when wild birds have close contact with domesticated birds, such as chicken, ducks, and turkeys, avian influenza can be easily spread to the domesticated birds and can make them very sick and kill them in a short period of time. Infected birds shed influenza virus in their saliva, nasal secretions, and feces. Susceptible birds become infected as a result of having contact with contaminated secretions or excretions or with surfaces that have come into contact with these substances. Besides human beings, pigs, ferrets, tigers and leopards in zoos in Thailand, and domestic cats (who were fed raw infected chickens under experimental conditions in Germany) have also been infected with bird flu.

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