How to Fight USA300

October 5, 2007

A super strain of methicillin-resistant staphylococcus aureus (MRSA) is sweeping America and the rest of the world. Dubbed USA300, it is responsible for rising rates of MRSA infections among sports teams, clubs, families, and other groups. If not handled properly the super bug can result in necrotizing fasciitis, severe scarring, physical disability, even death.

A super strain of methicillin-resistant staphylococcus aureus (MRSA) is sweeping America andthe rest of the world. Dubbed USA300, it is responsible for rising rates of MRSA infections amongsports teams, clubs, families, and other groups. If not handled properly the super bug can result innecrotizing fasciitis, severe scarring, physical disability, even death.

"This super strain causes problems even in healthy, nonimmunocompromised people," warned MarkPeluso, MD, head team physician at Middlebury College in Middlebury, Vermont. "You have to jump righton these infections. They can get very bad very fast."

Community-acquired MRSA first surfaced in the sports community in a British rugby team in1998, Dr Peluso said during the American Academy of Family Physicians 2007 Scientific Assembly Fridayin Chicago. Five players developed non-healing abscesses from a strain of MRSA that was geneticallydistinct from hospital-acquired MRSA strains. The same strain has struck prisons, families, schools,and other locations where people come into close contact.

By 2000, Morbidity and Mortality Weekly Report was reporting MRSA outbreaks in college sportsteams, high school sports teams, and private sports clubs nationwide. The first MRSA outbreaks amongteams with which Middlebury competed appeared in 2004, Dr Peluso reported.

In 2005, MRSA hit the cover of Sports Illustrated. The same year, the New England Journal of Medicinereported on the first recognized MRSA outbreak in a professional sports team, the St. Louis Rams.

All of these outbreaks were linked to the same USA300 strain of MRSA, Dr Peluso noted.Resistance is based on the mecA gene, which codes for methicillin resistance. The gene is located ona small mobile element that spreads easily and rapidly from one strain of MRSA to another.

The reported outbreaks had no known link, Dr Peluso said, but they all shared severalfeatures. Athletes who were infected typically had turf burns or other superficial wounds, as well asshared items, including towels, personal grooming products, equipment, trainers, and trainingfacilities. Many also shaved areas other than their faces, usually for cosmetic reasons.

New England Journal of Medicine researchers found multiple pathways for infection. Thefootball players who were infected typically received three to five turf burns weekly and theirwounds were frequently left uncovered. Trainers who tended to these minor wounds had poor handhygiene, seldom washing their hands between treating different players.

In addition, players routinely shared towels, rarely showered before using whirlpools, andalmost never cleaned weight training or other equipment before use.

But for all the worries about super bugs sweeping the nation, the Rams and many other teamshave successfully controlled MRSA outbreaks. Dr Peluso had to deal with a Middlebury outbreak thatwas eventually traced to an unlicensed tattoo artist.

"Basic infection control measures are what it takes," he said. "You don't have to do anythingexotic, you just have to do the basics that we all know and do them well."

Middlebury replaced soap bars in athlete showers with liquid soap, added more towels andactively discouraged athletes from sharing towels and all other personal items. Coaches and otherstaffers were trained in hand hygiene and given adequate supplies of alcohol-based hand cleansers andexam gloves.

On the field, athletes are barred from practice or competition until all wounds are properlydressed. In locker rooms and other facilities, equipment and surfaces are cleaned frequently withcleansers as recommended by manufacturers. In weight rooms, athletes have been trained to clean allequipment before they use.

"We tell them that afterward is helpful, too, but be sure to disinfect that bar before youtouch it," Dr Peluso said. "You don't know who just used it or what kind of infection they mighthave. When you tell these athletes that getting a MRSA infection is going to sideline them, theylisten."

Similar measures can be used to prevent and control MRSA outbreaks in families and othersettings. The basics remain the same, Dr Peluso explained: good hand hygiene; prompt and proper woundcare; and no sharing of towels or other personal items.

"You have to teach your moms and dads and kids to get on it right now," he concluded. "Thetake-home message for all of us, in any practice setting, is the same: this can get bad in ahurry."

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