Misguided on MRSA
By Jill Appell
| Tuesday, January 01, 2008
MRSA — with recent news reports on the deaths of otherwise healthy individuals from the bacterial infection, that acronym is striking fear among the public. Now some U.S. pork industry critics are latching on to recent European and Canadian studies that found methicillin-resistant Staphylococcus aureus — MRSA — on pigs and are using that trepidation to push policies that would adversely affect producers.
The oddly named group, Keep Antibiotics Working, said the Canadian study points “to animal agriculture as a source of the deadly bacteria.” Newspaper editorials have all but blamed pigs for spreading the sometimes deadly infection. One said “the trail of MRSA is winding through pig farms in Canada and in Europe,” and have called for surveillance and testing of all U.S. swine.
What is MRSA?
MRSA is a type of Staphylococcus aureus, a common bacterium found throughout the environment. It's arried in nasal passages and on skin of more than 30 percent of the human population. It is resistant to certain antibiotics and has been found on people, cats, dogs, horses, marine mammals, turtles, rabbits and a variety of food animals. Most people who have MRSA do not become sick and are not aware that they carry it.
There are at least three general categories of MRSA. Virulent forms of it are a serious human health problem and are most commonly found in health-care settings such as hospitals, dialysis centers and long-term care facilities. These forms can cause serious, invasive illness and even death, particularly in people with weakened immune systems.
Less virulent forms are commonly found among humans and on cats, dogs, horses and other animals.
A third form, which is less invasive than the health-care-associated forms, was recently discovered on swine farms in the Netherlands and in Canada.
Critics are using those discoveries to claim that pigs are responsible for the rising incidence of MRSA either because they are carriers of the bacterium, because their meat contains it or because the antibiotics they receive are contributing to drug resistance — or all three.
Bills are lining up
In addition to advocating the testing of all pigs, critics are urging a ban on the use of certain antibiotics in livestock and animal feed. There are several bills pending in Congress, including ones sponsored by Sen. Edward Kennedy (D-Mass.) and Rep. Louise Slaughter (D-N.Y.) that would do just that — ban antibiotics.
Such efforts, and the media hyperbole about pigs and MRSA are doing a disservice to legitimate efforts in the public-health and scientific communities to understand and respond to the risks of MRSA.
The U.S. pork industry is committed to working with public-health agencies, including the Centers for Disease Control and Prevention, and the scientific community to find solutions to MRSA. In fact, the industry has funded research in the United States to determine if MRSA is present in the domestic swine herd. The industry supports additional epidemiological research and surveillance systems in hospitals and health-care communities to monitor the disease. The industry also has established a panel of U.S., Dutch and Canadian researchers to discuss and coordinate U.S. and international research efforts on MRSA in pigs.
Right now, there is not enough information to make pigs the culprits in the recent rise in MRSA cases — particularly since many are related to places such as gyms and locker rooms, which are far from the farm. In fact, despite the close contact with swine, there is no data indicating that pork producers or workers are more susceptible to MRSA than the rest of the population. In the Canadian study, for example, while one-fifth of the producers were found to be carrying the same form of MRSA as their pigs, they did not have a higher rate of MRSA-associated illness than the general population.
And despite suggestions to the contrary, MRSA is not a food-safety issue. The Dutch food-safety authority, the National Institute for Public Health and the Environment, conducted a risk assessment in the Netherlands and concluded that the MRSA present in food animals such as pigs is not a food-safety threat.
Finally, there is no evidence linking antibiotic use in pigs with the development of MRSA's more virulent forms that have surfaced. MRSA found on pigs does not cause illness in the animals, so producers do not use antibiotics to control it. It’s important to point out that a recent Institute of Food Technologists’ report stated that correlating the risk of using antibiotics in animals and antibiotic resistance in humans is not possible.
The antibiotics that producers do use on their pigs are employed sparingly, and the pork industry promotes judicious use through its “Take Care — Use Antibiotics Responsibly” program.
While the U.S. pork industry shares the public’s concerns about illness-causing bacteria such as MRSA that are resistant to treatment with antibiotics, it will not jeopardize the livelihoods of 67,000 pork producers by succumbing to critics’ fear-mongering.
