Perirectal abscess infections related to MRSA: a prevalent and underrecognized pathogen

Methicillin-resistant Staphylococcus aureus (MRSA) is not a commonly recognized pathogen isolated from perirectal abscesses. Complex perirectal abscesses of MRSA origin may present a significant challenge to the physician and result in treatment failure. The aim of our study was to determine the prevalence of MRSA in our patient population with perirectal abscesses and whether antibiotics coverage, if given, was adequate.

We conducted a retrospective study of all adult patients who presented with a perirectal abscess. The bacteriology of the cultures taken from more than 100 patients during an 8-year period was examined. The prevalence of MRSA was specifically analyzed, and the sensitivities of the organisms isolated were then compared with any antibiotics prescribed to determine the adequacy of coverage.

In all, 124 patients were treated for perirectal abscess during the 8-year period. Fifty-nine percent of patients were taken to the operating room for incision and drainage, 52% of the patients had cultures taken of the abscess, and 35% of patients were given antibiotics coupled with incision and drainage. The antibiotics offered adequate coverage when compared with the sensitivities of the organisms 73% of the time. The prevalence of MRSA in our patient population was 19%, and when this organism was cultured, the patient only received adequate coverage 33% of the time.

The presence of MRSA in perirectal abscesses is underrecognized. Recent data has shown that incision and drainage combined with antibiotics offers a superior outcome in soft tissue abscesses caused by this organism. If cultures are not routinely taken at the time of incision and drainage, the institutional incidents of MRSA will remain unknown. Physicians must recognize that MRSA is a potential organism present in perirectal abscesses when considering antimicrobial therapy for complex abscesses.