Misuse of flu drug seen in China
Made for humans, given to chickens
HONG KONG -- Chinese farmers, acting with the approval and encouragement of government officials, have tried to suppress major bird flu outbreaks among chickens with an antiviral drug meant for humans, animal health specialists say.
International researchers now say this is why the drug will no longer protect people in case of a worldwide bird flu epidemic.
China's use of the drug amantadine, which violated international livestock guidelines, was widespread several years before China acknowledged any infection of its poultry, according to pharmaceutical executives and veterinarians.
Since January 2004, avian influenza has spread across nine East Asian countries, devastating poultry flocks and killing at least 54 people in Cambodia, Thailand, and Vietnam, but none in China. World Health Organization officials have warned that the virus could easily undergo genetic changes to create a strain capable of killing tens of millions of people worldwide.
Although China did not report an avian influenza outbreak until February 2004, executives at Chinese pharmaceutical companies and veterinarians said farmers were widely using the drug to control the virus in the late 1990s.
The Chinese Agriculture Ministry approved the production and sale of the drug for use in chickens, according to officials from the Chinese pharmaceutical industry and the government, although such use is barred in the United States and many other countries. Local government veterinary stations instructed Chinese farmers on how to use the drug and at times supplied it, the animal health specialists said.
Amantadine is one of two types of medication for treating human influenza. But researchers determined last year that the H5N1 bird flu strain circulating in Vietnam and Thailand, the two countries hardest hit by the virus, had become resistant, leaving only an alternative drug that is difficult to produce in large amounts and much less affordable.
''It's definitely an issue if there's a pandemic. Amantadine is off the table," said Richard Webby of St. Jude Children's Research Hospital in Memphis.
