PHILADELPHIA – College athletes who play contact sports are more likely than are those who play noncontact sports to carry methicillin-resistant Staphylococcus aureus, putting them at higher risk for infection and for infecting others, according to findings from a 2-year observational study.
During the course of the study, MRSA colonization ranged from 8% to 31% in 224 students who played contact sports, including football, basketball, soccer, and lacrosse, compared with 0% to 23% in 153 students who participated in noncontact or limited-contact sports, including baseball, cross country, and golf. MRSA colonization in the general population ranges from 5% to 10%, Natalia Jimenez-Truque, Ph.D., of Vanderbilt University Medical Center, Nashville, Tenn., reported at an annual scientific meeting on infectious diseases.
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Athletes should be advised about MRSA and good hygiene practices to reduce the risk of infection.
Overall, contact sports athletes in this study had more than twice the risk of being colonized with MRSA (odds ratio 2.3), and tended to carry S. aureus for longer period of time (OR 3.0 for intermittent carriage, 2.39 for persistent carriage), compared with noncontact sports athletes. Also, contact sports athletes who were not carriers at baseline acquired S. aureus more quickly (hazard ratio 1.6), Dr. Jimenez-Truque said during a press conference at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
The findings have implications for advising young athletes about the importance of good hygiene practices, including covering any open wounds, washing hands frequently, showering as soon as possible after all practices and games, laundering gym clothes, bags, and towels promptly, and not sharing razors and other personal hygiene items, she said.
Athletes are known to have a higher risk of infection with S. aureus than the general population, but most studies have not assessed staphylococcal carriage or compared risk in contact and noncontact sports participants, Dr. Jimenez-Truque said. The lack of available information about the natural history of carriage across sports limits strategies for preventing infection in athletes, she noted.
For the current study – the first to observe both male and female college athletes who were not part of a MRSA outbreak – Dr. Jimenez-Truque and her colleagues followed varsity collegiate athletes from August 2008 to April 2010. Nasal and oropharyngeal swabs were collected at enrollment and monthly thereafter.
The increased rates of MRSA carriage and acquisition in contact sports athletes in this study may be associated with increased likelihood of having cuts, scrapes, turf burns, and skin-to-skin contact with other athletes, further underscoring the need for good hygiene, she said.
MRSA is a leading cause of both invasive and skin and soft tissue infections. Athletes are commonly affected, and up to 70% of those who develop infection require hospitalization and intravenous antibiotic treatment.
However, despite the “really significant number” of contact sports athletes who carry MRSA, the number who become infected is small, Dr. Jimenez-Truque said.
“What that tells us, we think, is that colonization with specific strains of staph in specific people at specific times is needed for infections to occur, and therefore for outbreaks to occur. When we put it in that sort of framework, we begin to realize that we need to understand the epidemiology of specific strains of S. aureus, we need to understand the periods of time when athletes are at highest risk – that’s probably when they’re newly acquiring strains that they’ve never seen before – and we need to take into account things that we can do that may be unrelated to staph, but may affect their risk for infection,” said lead author C. Buddy Creech, also of Vanderbilt University Medical Center.
For example, during the course of the current study, a cluster of infections “perfectly coincided” with the development of pandemic H1N1 influenza in a number of athletes, Dr. Creech said, adding that even though the two conditions are unrelated, this relationship between S. aureus and influenza shouldn’t be diminished.
“So even though it’s unrelated, all of the things we do to protect collegiate and professional athletes, like influenza vaccination and general health maintenance ... go a long way, and may have widespread implications,” said Dr. Creech.
He noted however, that although strategies of covering compromised skin and wounds are important for preventing the spread of disease, they are comparable to “putting our finger in the dike while we wait for other preventive strategies like vaccination or other more powerful strategies.”
Dr. Creech and Dr. Jimenez-Truque reported having no disclosures.