As residents of North Carolina, the country’s leading pork-producing state, will readily tell you, hog confinements aren’t kind to the nose. But while the stench of factory farms is a given, researchers at the Johns Hopkins Bloomberg School of Public Health looked at something else that may end up in the noses of workers at hog farms for a study published last week in the journal Occupational and Environmental Medicine—the bacteria Staphylococcus aureus, or staph.
Although roughly a third of Americans carry the bacteria without becoming sick, it’s more widely feared in its more notorious guise, methicillin-resistant S. aureus, or MRSA. The antibiotic-resistant strain can be deadly, with infections resulting in 9,670 deaths in 2012, according to the Centers for Disease Control and Prevention. If hog confinements, in which animals living in close quarters are routinely fed antibiotics, are an ideal breeding ground for MRSA, public health researchers want to know if the bug is making its way off the farm. So the Johns Hopkins scientists turned to the noses of 22 workers in North Carolina to see what forms of staph they might find there.
While only one worker was found to be carrying MRSA after nostril swabs were tested, 86 percent carried staph bacteria associated with livestock—far higher than the general population. Ten of the workers, nearly half of the rather small sample, were found to have strains resistant to one or more drugs. Furthermore, the persistence of the presence of the various strains in workers’ noses was longer-lasting than was seen in similar studies, sometimes as long as 96 hours.
“If workers continue to carry it over a period of days, they are going to be interacting with their families and in their communities, and the question for public health officials then is whether they pose any greater risk,” coauthor Christopher D. Heaney, an environmental health sciences and epidemiology professor at Johns Hopkins, told The New York Times.
Last summer, Heaney was involved with a similar study that revealed 40 percent of workers at a North Carolina hog farm carried staph, including a number of instances of MRSA. The researchers also looked at an antibiotic-free farm for that study and found no resistant bacteria in that environment.
“What’s remarkable is while everyone in the study had direct or indirect contact with livestock,” he told TakePart at the time, “we only observed drug-resistant [bacteria] with multiple genetic characteristics in the industrial group.”
Which seems to back up what practically every public health organization in the world has been saying: Antibiotic use in agriculture presents a real danger to human health, and the institutionalized use needs to stop if we want to avoid a potential epidemic. Finding MRSA in just one nose may not seem like much, but if the bug is jumping over the farm fence, it could spread among the human population too.