The idea that methicillin-resistant Staphylococcus aureus (MRSA) abscesses don’t always require antibiotics (Item 122-5) may have been accepted in 1950, but it is not true anymore. All clinicians know that every family member should be treated once MRSA is diagnosed. Once again, the CDC is behind on its protocols. Treatment should consist of appropriate oral antibiotics—not mupirocin (Bactroban). Because the nose is the primary reservoir in the carrier state, MRSA is mainly spread via nasal droplets. No amount of hand-washing will change that.
—Rolf Lyon, MD, Lecanto, Fla.

According to John M. Boyce, MD, director of the division of infectious diseases at St. Rafael’s Hospital in New Haven, Conn., “Patients with fluctuant or purulent skin and soft-tissue infections should undergo incision and drainage, and debrided material should be sent for culture and susceptibility testing. Incision and drainage alone may be sufficient for abscesses smaller than 5 cm. This was illustrated in a randomized trial of 166 patients with uncomplicated skin abscesses at risk for community-associated MRSA who were managed with cephalexin or placebo following incision and drainage of skin and soft-tissue abscesses; the cure rates were similar in the two groups (84% and 90%, respectively). Among the isolates tested, 88% were MRSA; because cephalexin does not have activity against MRSA, the cephalexin arm was also a functional placebo arm in this group” (Boyce JM. Epidemiology of methicillin-resistant Staphylococcus aureus infection in adults. In: Rose BD, ed. UpToDate. Wellesley, Mass.: UpToDate; 2009).

With regard to hand washing, Dr. Boyce states, “Hospital-associated MRSA strains are most commonly transmitted to patients via the transiently contaminated hands of health-care workers. Hospitalized patients may also acquire MRSA from contaminated environmental surfaces. Community-acquired MRSA strains are most commonly transmitted by direct contact with a colonized or infected individual … (or) by contact with contaminated fomites used by an affected individual. Adherence to infection control measures is critical for interrupting MRSA transmission.” He describes transmission through “contact with contaminated wounds or dressings of infected patients; contact with another individual’s colonized intact skin; contact with contaminated inanimate objects; (and) by inhalation of aerosolized droplets from chronic nasal carriers.” Dr. Boyce concedes that the anterior nares is the most common site of MRSA colonization but goes on to say that “a majority of individuals with nasal colonization are also colonized on other areas of intact skin, including the hands, axillae, perineum, and umbilicus (in infants). Other potential sites of MRSA colonization include surgical wounds, decubitus ulcers, intravascular catheter sites, throat, sputum, stool, and genitourinary tract. In one study of hospitalized patients with S. aureus colonization, 67% had colonization of the GI tract, which was associated with increased frequency of S. aureus skin colonization.”

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All of this suggests that hand-washing is an effective means to reduce MRSA transmission. – Reuben W. Zimmerman, PA-C (125-9)