SAN FRANCISCO—An empiric antibiotic treatment algorithm for community-acquired methicillin-resistant Staphylococcus aureus skin and soft tissue infections improved clinical outcomes, according to the results of a small study.
“We recommend treating people with skin and soft tissue infections with Bactrim and Keflex or clindamycin in addition to early incision and drainage,” Dr. Erin A. Chuck said in an interview during a poster session at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
She and her colleagues at Alameda County Medical Center in Oakland, Calif., reviewed the charts of 50 consecutive patients treated in the ED for laboratory-confirmed community-acquired methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections and were sent home the same day between April 2005 and January 2006. They categorized treatment as either conforming to or not conforming to the algorithm, which classified infections as follows:
▸ Type 1: Uncomplicated cellulitis or impetigo. The recommended treatment was cephalexin (Keflex) plus trimethoprim-sulfamethoxazole (TMP/SMX).
▸ Type 2: Uncomplicated abscesses. The recommended treatment was surgery, but if antibiotics were used the researchers recommended doxycycline or TMP/SMX alone.
▸ Type 3: Complicated abscesses, such as those with surrounding cellulitis, infections in immunocompromised hosts, or infected wounds. The recommended treatment was to consider surgery, to administer oral Keflex plus TMP/SMX or clindamycin alone, or to administer intravenous clindamycin plus vancomycin or Zosyn (piperacillin sodium and tazobactam sodium) plus vancomycin.
Of the 50 patients, 37 had abscesses that were drained at the first visit, said Dr. Chuck, who conducted the study during her residency at the medical center.
Of the 29 patients treated according to the algorithm, only 1 (3%) was considered a clinical failure, vs. 13 (62%) who were not treated according to the algorithm.
Of the 36 patients treated with antibiotics that were active in vitro against their MRSA isolate, 4 (11%) were considered clinical failures. Of the 9 patients treated with antibiotics that were inactive against their cultured MRSA, 7 (78%) were considered clinical failures. No patient treated according to the algorithm was subsequently hospitalized, vs. two not treated according to the algorithm, she said at the meeting, sponsored by the American Society for Microbiology. Dr. Chuck is now a hospitalist at John Muir Hospital in Walnut Creek, Calif.