TRIN-GYI-PHO-NYA, Vol. 3, No. 3
By Minnie Wood*
At least 5,000 migratory birds have died from avian influenza at Tso-Ngon (Lake Kokonor) in the Amdo region of Tibet since early May 2005, according to the World Health Organization (WHO) and the Food and Agriculture Organization (FAO). These deaths include several species of migratory birds, including bar-headed geese, great black-headed gulls, brown-headed gulls, ruddy shelducks, and great cormorants. This is the first instance of widespread deaths from avian influenza in migratory birds—rather than domestic birds—indicating that the avian influenza virus may have become more dangerous. The Chinese government has not reported any cases of avian influenza in humans in the region.
Avian influenza, or bird flu, is a naturally occurring virus among birds. Wild birds are carriers of the virus but usually do not become ill from it. But avian influenza is extremely contagious and can cause domesticated birds like chickens and ducks to become sick and die. The particular subtype of bird flu that is currently circulating, H5N1, is deadly. Outbreaks of the disease have occurred in poultry in Vietnam, Thailand, Cambodia, China, Indonesia, Japan, Laos and South Korea. More than 100 million birds in these countries have died from the disease or have been killed (“culled”) in order to prevent its spread. In addition, there have been 108 cases of bird flu in humans and a total of 54 deaths. It is believed that humans become infected through contact with diseased birds and contaminated surfaces, including ingestion of raw or undercooked poultry. But much remains to be learned about specific modes of transmission,
Flu viruses can change rapidly and there is growing concern that a human infection with a bird and a human flu at the same time can give rise to a new type of influenza to which people will have no natural immunity. Such a disease could be devastating to human beings, resulting in a worldwide pandemic. From 1918 to 1919, a different subtype of flu killed approximately 50 million people around the world.
The WHO has expressed concern about the possibility of the spread of bird flu outside of the Amdo region and about the Chinese government’s efforts to test migratory birds and people in the area. Approximately 100,000 birds from 189 different species congregate at Tso-Ngon each year. Despite those numbers, and more than 5,000 bird deaths from the disease, only 12 birds and 2 humans have been tested for avian influenza. In addition, little is known about the specific migratory patterns of the different species, making early warning of other areas of Tibet, China and Asia, a difficult prospect. WHO officials have insisted that China step up efforts to tag and test birds, and to make laboratory findings from analyzed samples available to international organizations. Because the birds will resume their migratory pattern in August or September, flying south and west, attempts at tagging, tracking and testing birds must begin immediately.
China has also been the target of a recent WHO inquiry regarding its avian influenza prevention strategies. The Washington Post recently reported that the Chinese government condoned and encouraged the widespread use of the human antiviral medication, amantadine, in domestic poultry. The drug, which was fed to poultry, may have caused the H5N1 virus to adapt and become resistant to amantadine, rendering the medication useless to combat bird flu infection in humans. Researchers have already determined that the flu circulating in Vietnam and Thailand is resistant to amantadine.
Chinese officials have cordoned off Tso-Ngon, limiting access to the public. According to Chinese news agencies, vaccination of birds in the area is underway, but no migratory birds have been culled due to their protected status. Another outbreak of avian influenza has been reported in Tacheng city, in Xinjiang province; however international agencies have not yet been granted permission to visit.
Transmission of avian influenza occurs primarily though contact with infected poultry or other birds. The Centers for Disease Control (CDC) recommends avoiding contact, whenever possible, with poultry and any surfaces that may have been contaminated by them or their bodily secretions. The CDC also cautions against eating uncooked poultry or poultry products, including blood. All foods from poultry should be cooked thoroughly. As with all infectious diseases, the most important preventive measure anyone can take is washing hands and contaminated surfaces thoroughly with soap and water. These, and other public health measures, may be difficult to implement in areas of Tibet like Amdo in which the population is extremely spread out and may lack resources such as running water.
For more information about avian influenza, see: World Health Organization
; Centers for Disease Control
; Flu in China—Flu Information Centre*Minnie Wood is a graduate student at the University of California San Francisco. She served as the Executive Director of Tibet Justice Center from 2001-2004. Email: Minnie.Wood@ucsf.edu