H1N1 Found in First US Commercial Swine Herd - Keep Your Eye on Factory Farms, China, and the Birds

Though it would appear that people can infect pigs with H1N1, it is not clear whether live pigs can infect people. For now, officials are far more worried about the former than the latter.
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On Monday, the USDA reported that pigs in a commercial swine herd at an Indiana factory farm had tested positive for novel H1N1 influenza virus. It was the first time that pigs raised for meat in the US had been found with signs of the bug. Last month, show pigs at the Minnesota State Fair also tested positive for H1N1.

This time, 3,000 "finishing hogs" being fattened for slaughter were suspected of contracting the disease. "Information points to a recent exposure of the pigs with facility caretakers who were exhibiting influenza-like symptoms," said the website PigProgress.net. "Recovered healthy pigs are being sent to slaughter through normal marketing channels and State public health officials have been notified of the situation."

Agriculture and health officials have adopted a low-key posture toward the outbreak, noting that herd surveillance is working, and that the pigs in question cleared the virus and recovered on their own. They insisted there was no threat to public health.

The USDA has long pointed out that H1N1 cannot be transmitted by eating or handling pork products, and that US pork is completely safe. And though it would appear that people can infect pigs with H1N1, it is not clear whether live pigs can infect people. For now, officials are far more worried about the former than the latter.

The name and location of the Indiana pig producer have not been released, but with at least 3,000 hogs, it would qualify as a "Concentrated Animal Feeding Operation," or CAFO - better known as a factory farm. Meanwhile, the USDA has stated there is "currently" no evidence that the 2009 pandemic H1N1 virus originated in a CAFO. "Animals reared in a CAFO setting have a lower incidence of infectious disease compared to those kept in free range operations," the agency says.

There may be no proof that the current virus emerged from a CAFO, but there are plenty of suspicions - compounded by the fact that six of the eight genetic components in the currently circulating virus are direct descendants of a swine flu virus that first emerged in North Carolina a decade ago. That bug was discovered in August 1998, at a 2,400-head breeding facility in Newton Grove, NC, where all the sows suddenly came down with a phlegmatic cough.

Meanwhile, the bad news out of Indiana could not come at a more delicate time for the US hog industry, which has been hammered by falling prices due to a global economic slump and trepidation about US pork, especially among some of the biggest foreign customers - such as China.

Just last week, USDA Secretary Tom Vilsack announced that China "intends to re-open" its vast market to US pork and live swine, following a ban that was swiftly imposed last May when H1N1 was first identified.

At the time, China was the fastest growing market for U.S. pork, valued at some $560 million in exports. US officials had pressed upon the Chinese on "the need for China to remove all restrictions on trade in pork products related to the H1N1 virus, given clear guidance from international bodies like the World Organization for Animal Health (OIE), World Health Organization (WHO), and Food and Agriculture Organization (FAO), that there is no risk to humans from consuming properly prepared pork and pork products," a USDA press release said.

Pig growers from North Carolina to North Dakota will be watching closely for the next move by the Chinese. Those $560 million are sorely missed. But the latest discovery in Indiana will do little to enhance the reputation of US pork.

Finally, there is the very real fear that the virus might jump from pigs to birds, and from there, a newly mutated virus could become a deadly avian flu for people.

While researching my new book, Animal Factory (St. Martin's Press, 2010) I spent weeks touring the CAFO-heavy counties of Indiana, Illinois, Iowa, Michigan, Missouri, Ohio, North Carolina and elsewhere. One thing that struck me was how close the massive pig farms were situated to the equally huge poultry operations.

Swine and poultry CAFOs are supposed to be completely closed environments, in order to protect the animals from outside diseases. But they are not hermetically sealed, and pathogens can enter and exit in many ways - including workers, and flies, a proven vector of CAFO diseases. Some swine CAFO's recover water from their waste lagoons and recycle it back into the animal housing to wash out the barns, while also cutting down on dwindling groundwater supplies. But wildfowl routinely land in CAFO lagoons, where they can easily shed influenza virus into the water. This can also happen at facilities that use water from nearby ponds or rivers.

The USDA is worried enough about swine-to-avian transmission to have conducted at least one study on the subject, citing "concern that birds might be affected by the 2009 pandemic H1N1 influenza virus."

USDA scientists took a 2009 pandemic H1N1 virus isolate from a person and used it to infect four species of birds: ducks, chickens, turkeys & quail. None of them "became clinically ill after clinical infection," the agency said, adding that officials "continue to monitor the evolution of influenza viruses in birds in case changes occur and the H1N1 flu virus adapts and can spread in poultry."

The study "has been scientifically reviewed and concluded that these four species of
birds are not likely to be vehicles for transmission of the 2009 pandemic H1N1 influenza
virus," the USDA said, adding that its study "will be published in a scientific journal in the near future."

Because H1N1 virus continues to evolve, USDA vows to remain vigilant, especially after receiving a report from the Chilean government that the virus has been found in turkeys in that country. "USDA is validating these results," the agency said, and it "plans to conduct experiments in birds to determine how the Chilean H1N1 isolate compares to the novel North American H1N1 isolate in the ability to infect turkeys and
other birds."

Meanwhile, the USDA is imploring farmers not to let us disease-ridden humans around their delicate, vulnerable swine. "Permit only essential workers and vehicles to enter the farm to limit the chances of bringing the virus from an outside source," it says gravely.

In other words, if you have so much as a sniffle, don't get anywhere near a pig.

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