Concerns about the potential of a worldwide epidemic of avian influenza, or bird flu, are increasing amid a higher than usual number of deaths from the disease in South-East Asian. The World Health Organization (WHO) fears that the dangerous disease may become transmissible from person to person.
Last year 45 people died worldwide from the disease, which is normally contracted from close contact with domesticated birds. In comparison, 42 people have died since the end of January this year.
Over 140 million birds were slaughtered last year alone in attempt to prevent the spread of the bird flu. Presently, the virus has been found in other animals besides humans and birds who were not thought to be vulnerable to the disease, such as cats and tigers.
The first cases of bird flu in humans was diagnosed in Vietnam in January, followed closely by cases in Thailand and one case in Cambodia. This strain of bird flu has also been reported in Korea, China, India and Japan. Currently the disease is being monitored by the WHO's Communicable Disease Surveillance and Response group, who has confirmed 52 cases of bird flu.
In a press release the WHO emphasizes that "there is no evidence of human-to-human transmission." Experts have speculated that if the disease did mutate in a way that allowed such transmission then it would have the potential to claim more lives than SARS did two years ago , in which approximately 800 people died.
According to the WHO, antiviral drugs have shown some ability to combat the disease. Several prototype vaccines for the virus have also been produced from the virus found in Vietnam and a different virus isolated in Hong Kong. Large scale production of vaccines is not imminent as the drug has yet to undergo clinical testing.
While most people consider the flu a relatively nonthreatening disease, it has caused deadly epidemics in the past. In 1918 a human influenza pandemic swept the world, killing 21 million worldwide, with 500,000 dead in the United States alone. Government officials feared a resurgence of the "Spanish Flu" in 1976 after a flu outbreak at Fort Dix Army Base in New Jersey, but their fears proved unfounded. Since then many outbreaks have been prevented as a result of the flu vaccine.
The WHO has recommended that people "should avoid unnecessary contact with infected poultry, especially de-feathering or preparing sick birds for consumption in an area with recent chicken deaths." The Cambodian government is cooperating fully in the WHO's efforts. In the disease monitoring efforts the WHO is collaborating with the Pasteur Institute, the Cambodian Ministry of Agriculture, and the Food and Agriculture Organization (FAO).
Bird flu is not only a health hazard, but a significant economic hardship as well. Between 1983 and 1984 a bird flu outbreak in Pennsylvania cost an estimated $65 million after the destruction of over 17 million birds. The virus is capable of surviving in manure for up to three months and can therefore be difficult to eliminate from a population.
The bird flu is a variety of influenza A known as H5N1, which indicates what type of two different proteins the virus has on its outer shell. A virus' H or N designation, which stand for Hemagglutinin and Neuraminidase, can change or undergo "reassortment" in animals such as pigs. A pig becomes infected with both a human strain and a bird flu strain and new virus particles are produced that combine some attributes of both.
Influenza A, B, and C are the only members of the orthomyxovirus family, while Severe Acute Respiratory Syndrome (SARS) is caused by a virus in the coronavirus family.
