Monday, July 29, 2013

MRSA and Livestock




Nature gets into ongoing research on strains of MRSA found in hospitals and confinement operations.  I thought this section was interesting:
CAFO supporters acknowledge that farm strains of drug-resistant bacteria could theoretically spread to people. But “I don't see this equating to human health risk”, says Scott Hurd, a veterinarian and epidemiologist at Iowa State University who has conducted multiple studies to assess the risk of drug-resistant bacteria spreading through meat production. He says that the average person has a greater chance of dying from a bee sting than of contracting MRSA from pork. Hurd argues that limiting the use of antibiotics on farms could be harmful to human health. Even Smith's grocery-store study found that meat sold as 'antibiotic free' had the highest levels of garden-variety S. aureus, suggesting that untreated animals harbour more pathogens. “Animals really do need to be treated,” Hurd says.
Nevertheless, regulatory authorities have clamped down on antibiotic use on farms. The European Union began phasing out antibiotics for growth promotion in the late 1990s. Denmark led the charge with a full ban in 2000. (China, however, which claims half the world's pig population, has yet to rein in antibiotic use.)
The bans' effects on drug resistance and human and animal health have been murky. Levy and other supporters of the bans say that the result in Denmark has been positive, pointing to data showing a drop in the use of antibiotics on farms and an increase in meat production. But opponents, including the Animal Health Institute, point out that the use of antibiotics to treat acute illness in Denmark has increased, as have animal deaths.
Last year, amid mounting pressure from several groups, including the National Resources Defense Council, based in New York, the FDA released new guidance calling for the “judicious use” of antibiotics on farms. The agency discouraged the use of antibiotics for growth promotion and urged label changes to the drugs and more veterinary oversight for their application. Not all the guidelines are yet approved, and compliance is voluntary. Nevertheless, the agency has suggested that it will enforce tougher rules if farmers and drug-makers do not adopt the guidelines within about three years. Few are satisfied with the FDA's policy. Pig farmers and meat-industry representatives consider the move a blow to farmers and animal welfare, and supporters of antibiotic restriction say that the voluntary guidelines do not go far enough. Scientists, meanwhile, have pressed the FDA to reveal more data on how farmers are using antibiotics, so far without success.
I think it is kind of bogus to say that it is a big deal that untreated animals harbor more pathogens than treated animals.  No shit?  But constantly wiping out non-resistant bacteria just leaves resistant bacteria left.  I look at it like a septic tank.  If you dump some chemical down the drain that kills off all the bacteria, you've got a problem until the bacteria reestablish themselves.  Constant dosing with antibiotics has to screw with beneficial bacteria as well as harmful bacteria.

This issue, along with confinement practices and manure management are going to be the central issues of  livestock production for the foreseeable future.  More research needs to go into balancing animal welfare, minimization of antibiotic use and productivity to position the livestock industry to avoid unnecessary disasters. 

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