What causes MRSA? We know it's a drug-resistant bacterium, one not easily killed off by antibiotics. But where, exactly, are people coming into contact with this nasty pathogen that's responsible for nearly 80,000 infections a year?
Previously more prevalent in hospitals, increasingly, MRSA is striking out in the real world, where people are being sickened by community MRSA infections—a challenge the U.S. Centers for Disease Control and Prevention says we need to pay attention to. So where is all of this MRSA coming from? A new study published in JAMA Internal Medicine suggests modern farming practices could be a major root cause of community-aquired MRSA infections.
Read More: 9 Appalling Facts about Meat
Johns Hopkins Bloomberg School of Public Health researchers found that people living near large conventional pig farms or around a series of smaller ones were significantly more likely to be diagnosed with a MRSA or other soft-tissue infection.
And get this: Just living near a field that's been fertilized with pig manure increases your risk. In fact, people living in the areas with the highest level of swine crop field manure exposure faced about a 38 percent greater risk of a community-associated MRSA infection than people in areas with the lowest levels of exposure, according to lead study author Joan Casey, a Johns Hopkins graduate student.
While this study didn't look for problematic pathogens within pig manure, other studies have shown that swine waste can be contaminated with antibiotic-resistant bacteria, viruses like influenza and hepatitis E, drug residues, and metals.
Check the Map: Do You Live Near a Factory Farm?
"Other studies have shown that some of these contaminants, especially antibiotic-resistant bacteria, can travel from animal-production sites in the air and water," explains study coauthor Keeve Nachman, PhD, program director of the Food Production and Public Health Program at Johns Hopkins Center for a Livable Future. "Other vectors like flies and animal-transport trucks are capable of carrying these same bugs. There is concern that these environmental pathways and other vectors may result in human exposures to resistant pathogens."
Conventional livestock farms routinely feed animals low-dose antibiotics because the drugs speed growth (although scientists aren't exactly sure why the drugs have that affect). A whopping 80 percent of antibiotics used in the U.S. (about 30 million pounds) are used to fatten livestock; about 75 percent of the drugs pass through the animal's system, winding up in the manure. Once there, the drugs are exposed to additional germs that can also develop resistance.
While it may be tricky to know exactly what farmers are applying to fields near you, you may be able to press your county's conservation district for details. And remember, the more people buy organic food, the more farms will be forced to operate without routinely administering drugs!
Published on: September 19, 2013
Updated on: September 19, 2013