Despite growing evidence that feeding antibiotics to livestock can pose serious risks to humans, the FDA, long known to be in bed with big pharmaceutical and chemical companies, has done little to regulate the practice. Currently 80% of the antibiotic market is used for livestock.
Helping animals grow faster and put on more weight, industrial farms in the U.S. have been using antibiotics in livestock feed since the 1940s as a way to increase profits. Many industrial farms also use antibiotics to compensate for crowding, high stress levels among the animals, and unhygienic conditions.
A new study from scientists at Johns Hopkins, the University of North Carolina and George Washington University, show that the heavy use of antibiotics on industrial livestock operations may be behind the rise of antibiotic resistant superbugs.
Researchers divided their study subjects into two groups – those that work on industrial hog farms where antibiotic use is common practice and – those that worked on regular farms where antibiotic use is rare. Using a nasal swab from both groups and their families, researchers found that while staph bacteria were present in the noses of both studies, Methicillin-Resistant Staphylococcus aureus (MRSA) was found nearly twice the rate of industrial workers.
MRSA, responsible for the yearly deaths of 19,000 and nearly 365,000 hospitalizations, is an antibiotic-resistant staph that can cause pneumonia, meningitis, toxic shock, skin abscesses, heart valve infections and other serious medical conditions that often lead to death.
Many strains of MRSA are now resistant to antibiotics, including oxacilin, penicillin and amoxicillin. New strains are even developing resistance to stronger drugs like methicillin and vancomycin, only used as drugs of last resort.
Once MRSA is present in livestock operations, it can be easily spread to those who eat the meat. It can also enter the environment through animal manure and then make a jump to humans. Some studies have suggested that roughly 75% of antibiotics given to animals are not digested thus making up a large part of animal waste, which could end up being spread or sprayed on fields which allows it to contaminate ground and surface water. Insects that come into contact with this waste can spread it to other communities.
This is not the first study to sound the alarm. In one study published in the New England Journal of Medicine on February 6, 2002, researchers found links that strongly suggested that the people who developed Cipro-resistant bacteria had acquired them by eating pork that were contaminated with salmonella, that was resistant to the antibiotic flouroquine. Another New England Journal of Medicine study from Oct. 18, 2001, found that 20 percent of ground meat obtained in supermarkets contained salmonella. Of that 20 percent that was contaminated with salmonella, 84 percent was resistant to at least one form of antibiotic.
A study in the journal mBio, published by the American Society for Microbiology, showed how an antibiotic-susceptible staph germ passed from humans into pigs, where it became resistant to the antibiotics tetracycline and methicillin and then jumped into humans. Whole-genome analysis on a staph strain called CC398, a variety of MRSA, and 88 closely related varieties that emerged within the past decade in pigs has since spread to cattle, and poultry, proving that animal bacterium jumped into humans with close exposure to livestock.
Feeding antibiotics to animals is not only a major cause of antibiotic-resistant bacteria in the human food supply, but also results in the presence of antibiotic-resistant bacteria in animals and in their waste,” said Environmental Defense senior scientist Rebecca Goldburg, Ph.D. “Those bacteria can in turn colonize and infect farm workers, as well as contaminate water, air, and soil. With antibiotics, the more you use them, the faster you lose them. That’s because bacteria become resistant in response to being exposed to antibiotics. Antibiotic resistance is a serious and growing threat to human health, so it’s just plain foolish to be feeding vast quantities of antibiotics to chickens, pigs, and beef cattle.”