The incidence of MRSA SSTIs in HIV-infected persons has increased in the past decade in both community and hospital settings. In clinic-based studies, 3–11% of HIV-infected patients were found to develop an MRSA infection during follow-up (range 1–12 years), which was most commonly an SSTI [4, 5, 9, 20, 25, 38]. Furthermore, HIV-infected persons have a 6–18-fold higher rate of MRSA SSTIs compared with HIV-uninfected persons [4, 5]. The incidence of invasive MRSA infections (e.g.

bacteraemia) in HIV-infected persons has declined since the advent of HAART [23]. Nonetheless, HIV-infected persons still remain at an increased risk for S. aureus bacteraemia compared with the general population [53], with an estimated 16-fold increased RAD001 in vivo risk [6]. Overall, MRSA rates in HIV-infected persons may now be decreasing as a result of epidemiological trends similar to those in the PXD101 cell line general population; a recent study in the general population showed a 28% and 17% decrease in hospital-onset and healthcare-associated community-onset invasive MRSA infections, respectively [54]. Further, a study among HIV-infected patients found that the incidence of MRSA infections (primarily SSTIs) peaked in 2007 (51.0/1000) and has since declined [38]. Factors associated with MRSA infections among HIV-infected

persons are presented in Table 2 [4, 5, 10, 20, 23-25, 27, 28, 31, 32, 35, 38]. Recent studies among HIV-infected patients have shown that persons of younger age [4, Carnitine palmitoyltransferase II 38] and men (especially MSM) may be at heightened risk [25, 32, 38]. Poor immune status, as indicated by a low CD4 cell count and a high HIV RNA level, is a predictor of MRSA infections. A retrospective cohort study among HIV-infected outpatients found that a CD4 count <50 cells/μL was associated with a 2-fold increased risk for CA-MRSA infections [25]. Similarly,

a recent study reported a decreased incidence of MRSA infections as the CD4 count increased [41.7/1000 person-years (PY) for a CD4 count ≤50 cells/μL; 13.9/1000 PY for a CD4 count between 51 and 200 cells/μL; and 8.1/1000 PY for a CD4 count >200 cells/μL] [38]. A low nadir CD4 count (<200 cells/μL) has also been associated in one study with an increased risk for MRSA infection [20]. Further, a dose–response effect has been observed with increased HIV RNA level and a higher risk for infection [25]. Despite these findings, the rates of MRSA infections remain elevated even among HIV-infected patients with robust CD4 cell counts [5, 25, 38] (Table 2). Regarding HAART use, a study among 900 HIV-infected outpatients observed an 84% reduction in the odds for MRSA colonization or infection among HAART users [20].