H5N1 avian flu found in pigs, says Chinese expert

Aug 20, 2004 (CIDRAP News) – A step in the progression of avian influenza considered almost inevitable by experts in view of the widespread and continuing Asian outbreaks this year—its occurrence in pigs—has been taken, if a Chinese scientist's report is confirmed. Chen Hualan, director of China's National Avian Influenza Reference Laboratory, said at a conference today in Beijing that H5N1 avian flu had been found in pigs on several farms in the country this year and last.

Officials from the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO) were somewhat taken aback, according to news service reports, not because the disease's eventual occurrence in pigs was unexpected but because they had been unaware of this development until hearing Chen's talk. A highly regarded and well-known expert on avian flu, Chen made remarks during an ongoing 3-day meeting, the International Symposium on the Prevention and Control of SARS and Avian Flu. She called this development "a rather dangerous signal in terms of public health," according to an Agence France-Presse (AFP) report.

She told journalists later that avian flu had been found in pigs in southeast China's Fujian province in 2003 and in "another place" in 2004, according to a BBC News story. When asked to provide more details, Chen refused, AFP reports, and it was unclear whether she had been authorized to reveal this information or had spoken inadvertently. FAO began seeking more information from the Chinese Ministry of Agriculture immediately, says another AFP report. WHO officials warned against panic over the news until more information is available.

The concern surrounding avian influenza in pigs is that they are considered a "mixing vessel" where human influenza and avian flu viruses could reside concurrently and exchange genes, Ray Wadia of the WHO office in Beijing told AFP. This could render a new, more lethal strain of the disease that is transmissible from human to human, which in turn could lead to an influenza pandemic. "It's something we've long warned can happened . . . If it's confirmed, it's a new chapter that's been written in the bird flu story," he said.

One thing that requires clarification is whether the pigs were actually infected with the H5N1 virus or were simply found to harbor it in their snouts or other superficial body parts. The virus could exist in the snout, for example, simply from an animal's routing around on the ground in an area where avian flu has occurred, points out a BBC News story.

In other presentations at the Beijing conference, WHO China representative Hank Bekedam told the international audience that "eliminating [avian flu] from the environment altogether may be unrealistic. Containing it may be the most practical first step many affected countries can hope for at this time," a Jakarta Post article quotes him as saying.

Klaus Stoehr of the WHO Global Influenza Program urged Asian countries to commit more money to the study and control of avian influenza, saying "The unprecented outbreak of H5N1 avian influenza in Asia poses an unparalleled challenge to agriculture an public heealth services to reduce the risk of the emergency of an influenza pandemic," says the Post story. Reuters reports that experts at the conference said the likelihood of a major winter outbreak is likely, and Dr. Robert Webster of St. Jude's Children's Research Hospital in Memphis said recent events indicate to him "that the virus is endemic in the [Asian] region."

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