MRSA (methicillin-resistant Staphylococcus aureus) has distressed hospitals for more than forty years and also has been infecting individuals outside of healthcare settings since 1995. MRSA is responsible for 94,000 infections and 18,000 deaths every year in the United States. Because MRSA initially appeared on a US farm, many scientists, such as epidemiologist Tara Smith, have dedicated their research in determining whether farms’ use of antibiotics is contributing to the increased drug-resistant bacterial infections in humans.
Health experts and scientists are fearful of the possibility that these drug-resistant bacteria are escaping via farmworkers and meat. In fact, the US Food and Drug Administration (FDA) suggested more restraint in the use of antibiotics on livestock, which many other countries’ government health departments have recommended as well.
However, meat and agricultural industries claim that MRSA and other drug-resistant bacteria arise in hospitals. These industries affirm that meat production has a variety of safety measures that prevent drug-resistant bacteria from infecting humans.
A serious problem has been the lack of data on how farmers maintain safety procedures that prevent the spread of drug-resistant bacteria. This is because many farmers hesitate in allowing scientists access their facilities. However, scientists such as Smith are working hard at pinpointing the exact route these drug-resistant bacteria are taking to infect humans.
Many concentrated animal-feeding operations (CAFOs) employ the use of a combination of multiple antibiotics to fight outbreaks of diseases such as H1N2 influenza in pigs. Although these practices have been common for decades, few CAFOs have veterinarians on staff to advise on proper antibiotic usage. Without proper guidance, many CAFO operators use antibiotics liberally. Studies have found that some antibiotics increase the growth rate of pigs by 2.5%, which can substantially increase profits for farmers. A study conducted by the Johns Hopkins Center for a Livable Future found that 80% of antibiotics sold in the US in 2009 were used on farms.
Resistant microbes arise as a result of such broad antibiotic use. A 1979 study on tetracycline found that when farmers started using tetracycline, the number of tetracycline-resistant bacteria increased substantially and soon spread to the farmworkers’ intestinal tracts. Although S.aureus lives peacefully on the skin, it can become an aggressive pathogen if it enters through a wound. From there, it can eventually enter the bloodstream to cause harmful infections.
Smith hopes the results of her research will convince agricultural industries to stop the overuse of antibiotics. Although human health should be prioritized over farm animals, farmers will most likely not change their practices unless researchers can create safe and cost-minimizing procedures to replace antibiotic use.