August 5, 2010

Spread of MRSA in athletes examined

Buddy Creech, M.D., MPH

Spread of MRSA in athletes examined

Vanderbilt researchers have been working for years to document the increasing threat posed by methicillin-resistant Staphylococcus aureus (MRSA).

Now Buddy Creech, M.D., M.P.H., assistant professor of Pediatric Infectious Diseases, is working to pinpoint the public health threat posed by community-acquired MRSA (CA-MRSA) for athletes.

Buddy Creech, M.D., M.P.H.

Buddy Creech, M.D., M.P.H.

News reports of outbreaks in schools, especially among high school football players, have caused a fair amount of public fear in recent years, and for good reason. Some infections have proven to be life threatening.

“First we need to recognize that not all MRSA are created equally. Getting rid of all MRSA may not be necessary. Perhaps selectively treating people who carry MRSA strains that are highly associated with infections can give us a means of targeted prevention,” Creech said.

In an article published in July's Archives of Pediatric Adolescent Medicine, Creech reported one year's worth of surveillance of college men's football players and women's lacrosse players for MRSA. Athletes are at particularly high risk because of skin-to-skin contact and abrasions that allow points of entry for the bacteria through the skin barrier.

“What we saw was a pattern of peaks in players' nasal colonization rates during the peak of their sport's season. What was a little surprising was that despite very high rates of MRSA colonization, we did not see large outbreaks of MRSA disease,” Creech said.

While plenty of MRSA was found throughout the season, the infections that did occur were primarily due to one particular type of MRSA. Creech says that a particular strain called USA300 CA-MRSA is associated with most infections in athletes. While the first year of monitoring athletes turned up a low prevalence of USA300 CA-MRSA, an extension of the surveillance into the following season uncovered a small outbreak of USA300 CA-MRSA.

“We were able to show that players with CA-MRSA infections were linked to each other, playing similar positions or blocking each other,” Creech said.

Some of the latest evidence from Vanderbilt studies shows skin infections presenting in the Emergency Departments caused by MRSA increased three-fold between 2000 and 2004, and 70 percent were from community acquired strains of MRSA.

Creech's study has been extended for another two years to continue MRSA surveillance in athletes. More college athletic teams have been included to explore differences based on sport and to determine if colonization rates of MRSA are higher in contact sports.

Creech says the goal would be understand the spread of these bacteria in this population and what events are necessary to lead to an infection.

Soon, Creech hopes to test the prophylactic treatment of players persistently colonized with high-risk strains of MRSA to determine if MRSA infections can be prevented.