Over the past several years, athletes have been challenged by an opponent so small that it cannot be seen by the naked eye. This foe not only has the ability to affect the individual player’s ability to compete but may also be capable of defeating teams and even larger sports organizations. The opponent is methicillin-resistant Staphylococcus aureus (MRSA), a bacteria that has evolved over the past several decades into being resistant to a wide range of antibiotics which had been effective in the past.
The nature of certain sports, particularly those involving close contact, equipment-sharing and the utilization of shared training and treatment facilities, makes an ideal environment for the spread of infectious organisms. A recent article in the American Journal of Sports Medicine highlights outbreaks of soft tissue and skin infections among collegiate and professional athletes and their teams. One of the reasons MRSA outbreaks have received such considerable attention is the fact that, as opposed to some of the other infectious agents, this particular bacteria has the ability to spread rapidly and can be both limb- and life-threatening. Combined with its growing resistance to the more common antibiotics, early recognition of infections caused by this organism and, even more importantly, preventive measures at both the individual and team level is crucial.
Staphylococcus aureus bacteria are some of the most common bacteria responsible for infections in humans. It is commonly carried on the skin and in the nose. Approximately one third of all people are “colonized”. This means that the bacteria is normally carried on the individual, but may not be causing infection. When it is responsible for an active infection, it commonly involves skin and soft tissue but can also be responsible for blood-born infections, postoperative wound problems and pneumonia.
The subspecies of methicillin-resistant Staphylococcus aureus was first identified decades ago and seen most commonly in nursing homes and hospital-acquired infections. Its evolution most likely resulted from the widespread use and at times inappropriate use of antibiotics and perhaps through the use of antibiotics in food, as well as, the result of natural gene mutation. In the 1990s an increasing number of cases of infection caused by the methicillin-resistant Staphylococcus aureus were being recognized in otherwise healthy individuals. This has lead to the recognition that the original MRSA which was hospital acquired (HA-MRSA) and community-associated MRSA (CA-MRSA) seems to affect individuals in somewhat different ways.
HA-MRSA commonly affects the elderly, as well as, those patients with chronic disease, weakened immune systems and individuals requiring indwelling treatment catheters, such as patients undergoing dialysis. Most infections by this subspecies result in wound, urinary tract, blood stream infections and pneumonia. In 2007 it has been estimated that 1.2 million hospitalized patients were being infected each year and 423,000 were identified as being “colonized”. It is thought to represent 50-70% of hospital-acquired infections. Of concern is that the death rate from HA-MRSA is 2.5 times higher than from the more sensitive species of staphylococcus. The Center for Disease Control reported that the number of deaths from MRSA were greater than deaths caused by AIDS in 2005.
CA-MRSA represented 12% of all MRSA infections in 2003, but based on medical providers’ recent experience this percentage today is thought to be considerably higher. It is estimated that 1% of all individuals in the United States are MRSA “carriers”.
As noted above CA-MRSA usually effects otherwise healthy people. It’s most common manifestation is as skin and soft tissue infections. Certain high-risk groups have been identified. By their close contact, athletes, military recruits and even prisoners represent some of these. Children with their under-developed immune systems and certain ethnic groups, such as Pacific Islanders, Alaska Natives and Native Americans are more susceptible. Risk factors thought to be responsible for this involve close skin-to-skin contact, activities such as sports that often result in open skin wounds like cuts and abrasions, contaminated shared items including training equipment, close living conditions and poor hygiene.
Clinical Presentation of MRSA Infections
With its propensity to cause skin infection, CA-MRSA often presents as an infected pimple or skin boil. It is interesting to note that until recently many were thought to be the result of insect or spider bites. The infected area itself is red, swollen and often the pain associated with it may seem out of proportion to its appearance. Pus or other drainage may be present. While often the infection develops slowly, it can progress rapidly to a deep and painful abscess. During this phase a low-grade temperature may be present, as well as, “flu-like” symptoms. At this point it can progress rapidly to both limb- and life-threatening infections as it spreads to other organs locally or through the blood stream. In athletes, any infection or abscess developing in the area of a previous abrasion or “turf burn” should be highly suspicious for MRSA infection.
As with any infection, but even more so because of its very nature, infections caused by MRSA need to be diagnosed and treated promptly. It is essential that the proper antibiotics are started immediately even before wound culture results are available, which can take one to two days after medical care has been sought. Surgical incision and drainage of abscesses may be required. In cases that do not respond to initial treatment or are more advanced at the initial presentation require hospitalization, IV antibiotics and potentially surgery.
In the past the antibiotics of choice in the treatment of staphylococcus infections have been beta-lactam antibiotics. This is a class of widely effective penicillins, cephalosporins and other commonly prescribed antibiotics. The most commonly prescribed antibiotics used in the treatment of HA-MRSA and CA-MRSA are vancomycin and other closely related antibiotics. Unfortunately, however, MRSA resistance to these antibiotics seems to be emerging. Because of the increasing frequency of MRSA infections, non-beta lactam antibiotics are now commonly prescribed for those infections with suspicious presentations, in high-risk individuals and in certain areas of the country where MRSA seems to be more prevalent.
As in all infectious diseases, prevention is key, particularly for those individuals in high-risk groups, such as athletes. In general, the individual can minimize his own risk by practicing good hygiene such as frequent handwashing and proper wound care. In the case of the athlete, showering immediately after practice and game participation and avoidance of sharing personal items such as towels, razors and personal equipment are also important. Special precautions should be taken in training and treatment facilities catering to athletes. Exercise equipment should be wiped off between usages and should be thoroughly cleaned daily. Additional precautions need to be taken in athletic treatment areas involving examination tables, whirlpools, and even commonly used items such as treatment and medical devices. Individuals with any infection but particularly those caused by MRSA need to be isolated and all contaminated bandages and other treatment instruments need to be disposed of properly.
An excellent review of these preventive measures is available through the National Athletic Trainers Association Physician Statement from March 2007 which is available at the NATA website link at the conclusion of this article.
In closing, MRSA infections are of considerable concern within the healthcare community. Their increasing frequency and, in particular, their increasing emergence outside of the hospital environment is very worrisome. Being highly contagious and capable of causing considerable morbidity and mortality, early diagnosis and treatment of MRSA infections is of paramount importance. The prevention of MRSA infections and its spread is essential.
The athlete has specifically been identified as a member of the high-risk group for acquiring MRSA infections. The nature of many sports exposes the individual athlete to the possibility of infection through this agent, and others like it, and puts them at high risk. Extra attention in personal hygiene practices and special precautions in the use and maintenance of equipment in training and treatment facilities needs to be established and carried out routinely.