Such cases have generated enough anxiety that teams have pulled out all the stops to eradicate the germ or to prevent it from settling in.
Although the most recent study by the Centers for Disease Control and Prevention, in 2015, reported a decrease in MRSA infections in the general public since 2005, it is difficult to tell what is happening in locker rooms because there has been no study specifically on sports. Anecdotally, based on the number of cases they have treated in recent years, athletic trainers and team doctors nationwide have insisted that MRSA cases in sports declined substantially in the last decade. But they, too, have no data.
Moreover, the movement to curb MRSA in athletics is butting heads with new behavioral trends â like some teenagersâ dogged aversions to showering after games and practices â that imperil the best preventive efforts.
Likewise, practices like body shaving, which has become more popular among young people and can cause tiny cuts that allow MRSA to propagate, have been shown to increase the risk of infection sixfold, according to the National Athletic Trainersâ Association.
Football, like any sport with frequent skin-to-skin contact, continues to be a breeding ground for the disease. Professional football players are seven to 10 times more likely than the general public to have MRSA bacteria on their skin, according to Duke University researchers.
âIt is a job hazard present for people who play football,â said Dr. Deverick Anderson, a director of the Duke Infection Control Outreach Network, which serves as a consultant to the N.F.L.
MRSA, the acronym for methicillin-resistant Staphylococcus aureus, was once mostly found in hospitals, clinics and other health care settings. About 20 years ago, it began afflicting athletes in contact sports.
Over time, hospitals and other medical facilities developed more stringent hygiene routines that successfully reduced the prevalence of MRSA. It is these best practices that professional teams and athletic departments have spent the last decade emulating.
Sports teams, even at some high schools that have the necessary budget, tended to ramp up their preventive efforts with avant-garde measures.
In the N.F.L., the effort to curb MRSA now borders on a crusade, with an official prevention manual that is 315 pages long. There are meticulous protocols for dozens of procedures, right down to the approved method for refilling the anti-bacterial solution in hand-sanitizer dispensers, which are now omnipresent in locker and weight rooms. (Prepackaged containers are preferred to topping off the dispensers with a large jug â a process that can spread contamination.)
The best-intentioned and most sophisticated tactics, however, can be undone by the simplest omissions. At the high school and college levels, the downfall can be players who refuse to shower with teammates, which is common. A shower can greatly diminish the chance that exposure to MRSA in practice or in a game will lead to an infection.
âItâs like pulling teeth to get the athletes in the shower,â said Bernie Stento, an athletic trainer at Chesterton High School in Indiana. âSome kids are very squeamish about it. After practice, theyâre sweaty and have dirt and mud on them. In football, they might have cuts, scrapes and abrasions. I say to them, âGuys, without a shower, weâre inviting infection.â
âBut just as a practice ends, Iâll be taking things off the field and see kids leaving already.â
Itâs a phenomenon discussed often among coaches and trainers.
âIt started 10 or 15 years ago, and now there are a lot of social stigmas with the shower in a school setting,â said Bart Peterson, the head athletic trainer at Palo Verde High Magnet School in Tucson. âI donât know, maybe they donât want the hazing. But itâs pervasive.â
At Colgate, which is in upstate New York, a fervent education program has changed habits.
Owen Buscaglia, a junior wide receiver at Colgate, said he and his friends in high school considered it weird to shower after practice.
âNow itâs weird if you donât shower,â Buscaglia said.
Across the nation, the efforts to foster proper hygiene involve far more than shower routines. Some teams buy athletes their own water bottles to deter sharing.
To prevent teammates from sharing towels to wipe their faces or arms on the sideline, trainers have sometimes employed a small army of interns who scoop up any used towel so it can quickly be placed in the laundry. Jim Thornton, the athletic trainer at Clarion University in Pennsylvania, said his teams had begun using chemically treated towelettes that are about half the size of a standard towel and are discarded after each use.
The expense may be worthwhile. One study of high school football players concluded that sharing a towel makes the chance of a MRSA infection eight times more likely.