Pigs could be spreading MRSA, columnist warns; Purdue research says link is 'highly speculative'

There is growing concern that the use of antibiotics to treat prevent disease in healthy livestock may be increasing the amount of bacteria that are resistant to antibiotics. "We continue to allow agribusiness companies to add antibiotics to animal feed so that piglets stay healthy and don’t get ear infections," writes Nicholas Kristof for The New York Times. "Seventy percent of all antibiotics in the United States go to healthy livestock, according to a careful study by the Union of Concerned Scientists — and that’s one reason we’re seeing the rise of pathogens that defy antibiotics."

Agribusinesses typically adds antibiotics in livestock feed to prevent the outbreak of disease, which spreads quickly if animals are kept in crowded pens. "The peer-reviewed Medical Clinics of North America concluded last year that antibiotics in livestock feed were 'a major component' in the rise in antibiotic resistance," adds Kristof. "The article said that more antibiotics were fed to animals in North Carolina alone than were administered to the nation’s entire human population."

Health experts are growing more concerned with the increase in the number of cases of MRSA, an antibiotic-resistant staph infection, that kills 18,000 Americans annually. That is more than the number of Americans that die annually from AIDS. Hog farms seem especially prone to spreading MRSA. "Public health experts worry that pigs could pass on the infection by direct contact with their handlers, through their wastes leaking into ground water (one study has already found antibiotic-resistant bacteria entering ground water from hog farms), or through their meat, though there has been no proven case of someone getting it from eating pork," writes Kristof. "Five out of 90 samples of retail pork in Louisiana tested positive for MRSA. . . according to a peer-reviewed study published in Applied and Environmental Microbiology last year."

Legislation to eliminate the nontherapeutic use of antibiotics in agriculture has been blocked through strong lobbying efforts by agribusinesses, but some see President Obama and Secretary of Agriculture Tom Vilsack as hope for curbing the practice. (Read more)

Experts at Purdue University said that the link between pigs and the increase in the number of MRSA cases was "highly speculative." They insist that skin-to-skin contact between humans is a much more common way for MRSA to spread. (Read more)