Scientists call it a global game of ping-pong
Three weeks ago, the United Nations warned that avian flu is back on the rise after a five-year decline around the world.
A new strain of the H5N1 virus – and one for which there is no vaccine – had appeared in China and Vietnam, prompting the alarm. Now it’s shown up in India, too, and the government there has ordered poultry farms in the eastern part of the country to kill chickens and destroy eggs.
Bird flu can be deadly to humans, but it’s still not easily passed from birds to humans, although that could change at any time. Viruses mutate all the time, giving rise to new strains, which is why health authorities are on the alert.
One of the biggest concerns is that the critical mutation – one that would make humans easily susceptible to bird flu – could take place in pigs.
Meanwhile, a new strain of H1N1, or swine flu, has been discovered in North African pigs. Researchers from the University of California in Los Angeles came upon the H1N1 virus while they were in Cameroon. They believe the pigs there caught the virus from humans, noting that the strain is almost identical to the one that caused a scare in the United States two years ago. In that case, the humans caught the virus from pigs at a giant factory farm in Mexico. The pigs had caught a regular flu from factory farm workers, and then they’d picked up another flu virus apparently from birds migrating from Asia. The two viruses combined, leading to an outbreak of what we called swine flu, sickening around 60 million people as it spread around the world, and killing more than 12,000.
Now the human form appears to have bounced back to the pigs again.
Thomas Smith, who is part of the UCLA team that detected the virus in African pigs, said flu epidemics in pigs can have dangerous consequences for humans down line.
“[They] can be mixing vessels for other strains,” he said. “So they can get infected with other strains from birds, from chickens, from wild birds, etc. So these can mix and recombine into more serious forms.”
He called it a game of global ping-pong.
One of the nightmare scenarios is that pig farms will once again be the place where viruses get mixed together – worst of all in a situation where H1N1 swine flu, which is not so lethal to humans but is easily passed to us, gets mixed with H5N1, which is less easily passed to humans but is much more deadly.
Another nightmare scenario is one where bird flu gets mixed with the HIV AIDS virus, which is epidemic in Africa.
“Ultimately,” David Kirby, author of the book Animal Factory, told reporters a year ago, “when you cram thousands of animals into a single confined space without access to fresh air, outdoor sunlight, pasture, natural animal behaviors, you are asking for problems in the form of diseases that attack people.
“Mother nature will have the last word. Mad cow disease was a warning. Swine flu was a warning. MRSA was a warning. The egg recall was a warning.”
Kirby noted that in Iowa many chicken farms are located very close to pig farms. “Birds and rodents and insects are moving in and out of these places.”
He remains concerned that a new super-virus could arise, combining the killer bird flu and some killer swine flu.
“That could happen,” he said. “We haven’t hit the big one yet.”
To track the movement of bird flu, see this page on the website of the United Nations Food & Agriculture Organization. And for more information go here at the U.S. Centers for Disease Control and Prevention.
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