Letters to the Editor
To the Editors:
Within the last decade, there has been an increased incidence in methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTI) within the HIV-infected population.1 Research has identified low CD4 counts, intravenous drug use, male-to-male sexual contact, syphilis, end-stage renal disease, and recent beta-lactam antibiotic use as risk factors for MRSA SSTI in this population.1–4 Not surprisingly, recurrence of infection is high (27%) at 6-month follow-up.5 Therefore, treatment of these patients can be complicated. Skin and soft tissue infections in the general population often improve with incision and drainage alone, but patients with advanced immunosuppression and high rates of recurrence often require antibiotic therapy.6
Selection of empiric antibiotic therapy can be complicated in this population who frequently are exposed to trimethoprim-sulfamethoxazole for pneumocystis prophylaxis and doxycycline for treatment of chlamydia. To help determine which antibiotic should be the preferred empiric agent in MRSA SSTI, we reviewed all cases of SSTI with MRSA results by culture report in our Los Angeles–based clinics from 2005 to 2010. We studied the resistance patterns of all culture-proven MRSA SSTI from 2005–2010 (group 1) and then compared our data with the antibiogram of MRSA SSTI culture data collected in 2003–2004 (group 2) to ascertain if there has been a significant shift in the resistance pattern in the last 5 years.
During 2005–2010 (group 1), we identified 152 patients (12 females) who had culture-proven MRSA SSTI. Within group 1, TMP/SMX resistance was 5%, clindamycin resistance was 35%, tetracycline resistance was 13%, and rifampin resistance was <1%. Data from 2003 to 2004 demonstrate culture-proven MRSA SSTI in 64 patients (2 females). In this group, TMP/SMX resistance was 1.5%, clindamycin resistance was 17%, tetracycline resistance was 37.5%, and rifampin resistance was 0% (Fig. 1).
During the 5-year period, our data suggest an increase of MRSA resistance to TMP/SMX, clindamycin, and rifampin. Interestingly, we did note a decrease in tetracycline resistance. Resistance rates to TMP/SMX have increased, however, it remains lower than other agents, rendering it the preferred empiric antibiotic for MRSA SSTI in HIV-infected patients currently.
1. Mathews WC, Caperna JC, Barber RE, et al.. Incidence of and risk factors for clinically significant methicillin-resistant Staphylococcus aureus
infection in a cohort of HIV-infected adults. J Acquir Immune Defic Syndr. 2005;40:155–160.
2. Crum-Cianflone NF, Burgi AA, Hale BR. Increasing rates of community-acquired methicillin-resistant Staphylococcus aureus
infections among HIV-infected persons. Int J STD AIDS. 2007;18:521–526.
3. Burkey MD, Wilson LE, Moore RD, et al.. The incidence of and risk factors for MRSA bacteraemia in an HIV-infected cohort in the HAART era. HIV Med. 2008;9:858–862.
4. Lee NE, Taylor MM, Bancroft E, et al.. Risk factors for community-associated methicillin-resistant Staphylococcus aureus skin infections among HIV-positive men who have sex with men. Clin Infect Dis. 2005;40:1529–1534.
5. Skiest D, Brown K, Hester J, et al.. Community-onset methicillin-resistant Staphylococcus aureus
in an urban HIV clinic. HIV Med. 2006;7:361–368.
6. Krucke GW, Grimes DE, Grimes RM, et al.. Antibiotic resistance in Staphylococcus aureus
-containing cutaneous abscesses of patients with HIV. Am J Emerg Med. 2009;27:344–347.