Table 3. Factors associated with MRSA clinical infection among 600 HIV-infected adults, Atlanta, Georgia, USA, 2007–2009*.
| Factor | With MRSA clinical infection, n = 25 | Without MRSA clinical infection, n = 575 | Relative risk (95% CI)† | Adjusted relative risk (95% CI) |
|---|---|---|---|---|
| Median age, y (IQR) | 50 (45–58) | 52 (45–60) | p = 0.48 | |
| Sex | ||||
| M | 25 (4) | 565 (96) | 1.0 | |
| F | 0 | 10 (100) | NC | |
| Race/ethnicity | ||||
| Non-Hispanic Black | 22 (5) | 419 (95) | 1.0 | |
| Non-Hispanic White | 3 (2) | 147 (98) | 2.5 (0.8–8.2) | |
| Hispanic, other, or not specified | 0 | 9 (100) | NC | |
| HIV transmission risk | ||||
| MSM | 14 (4) | 301 (96) | 1.0 | |
| IDU | 3 (4) | 67 (96) | 1.0 (0.3–3.3) | |
| MSM and IDU | 0 | 19 (100) | NC† | |
| High-risk heterosexual contact‡ | 1 (3) | 34 (97) | 0.7 (0.1–4.7) | |
| No risk factor specified or other§ | 7 (4) | 154 (96) | 1.0 (0.4–2.5) | |
| CD4 cell count, median cells/μL (IQR) | 340 (85–482) | 419 (253–582) | p = 0.05 | |
| CD4 cell count, cells/μL (%) | ||||
| >500 | 5 (2) | 213 (98) | 1.0 | |
| 201–500 | 12 (4) | 257 (96) | 1.9 (0.7–5.4) | |
| ≤200 | 8 (7) | 105 (93) | 3.1 (1.0–9.2) | |
| HIV viral load, copies/mL (%) | ||||
| ≥400 | 14 (7) | 188 (93) | 1.0 | |
| <400 | 10 (3) | 374 (97) | 0.4 (0.2–0.9) | |
| MRSA baseline colonization | ||||
| Not MRSA colonized | 13 (2) | 508 (98) | 1.0 | 1.0 |
| MRSA colonized in groin | 12 (24) | 37 (76) | 9.8 (4.7–20.3) | 4.8 (2.1–10.8) |
| MRSA colonized in nares only | 0 | 30 (100) | NC | NC |
| Medical history | ||||
| Abscess | 11 (9) | 117 (91) | 2.9 (1.3–7.0) | |
| Cellulitis | 4 (10) | 36 (90) | 2.9 (0.9–8.8) | |
| MRSA clinical infection | 11 (14) | 70 (86) | 5.0 (2.4–10.7) | 3.1 (1.4–7.3) |
| MSSA clinical infection | 2 (4) | 48 (96) | 1.0 (0.2–3.9) | |
| Hospitalization in past 12 mo | 5 (6) | 79 (94) | 1.5 (0.6–4.0) | |
| Diabetes | 4 (6) | 67 (12) | 1.4 (0.5–4.0) | |
| Renal insufficiency | 5 (10) | 47 (90) | 2.6 (1.0–6.7) | 2.9 (0.9–9.3) |
| Syphilis | 10 (8) | 109 (92) | 2.7 (1.2–5.8) | |
| Current medications | ||||
| Antiretroviral therapy | 16 (3) | 458 (97) | 0.5 (0.2–1.0) | |
| Prescribed PCP§ prophylaxis | 4 (4) | 109 (96) | 0.8 (0.3–2.4) | |
| Prescribed TMP/SMX as PCP prophylaxis | 2 (3) | 78 (97) | 0.6 (0.1–2.4) | |
| Antibiotic use in past 1 y | ||||
| Any with anti–S. aureus activity¶ | 11 (4) | 260 (96) | 1.0 (0.4–2.1) | |
| Any fluoroquinolone | 3 (4) | 77 (96) | 0.9 (0.3–2.9) | |
| TMP/SMX, not as PCP prophylaxis | 7 (8) | 78 (92) | 2.4 (1.0–5.5) | |
| Azithromycin | 5 (5) | 88 (95) | 1.3 (0.5–3.5) | |
| Vancomycin or linezolid | 3 (14) | 19 (86) | 3.6 (1.2–11.1) | |
| Resided in past 12 mo | ||||
| Prison or jail | 5 (12) | 37 (88) | 3.3 (1.3–8.4) | 2.5 (0.97–6.7) |
| Homeless shelter | 2 (5) | 42 (95) | 1.1 (0.3–4.5) | |
| Sexual behavior in past 12 mo | ||||
| Sexually active | 16 (4) | 368 (96) | 1.0 (0.4–2.2) | |
| Sex with male same-sex partner | 11 (4) | 234 (96) | 1.1 (0.5–2.4) | |
| Sex with ≥2 male same-sex partners | 7 (5) | 130 (95) | 1.3 (0.5–3.0) | |
| Condom usage in past 12 mo | ||||
| Not sexually active | 9 (4) | 200 (96) | 1.0 | |
| Frequent or sometimes | 14 (4) | 318 (96) | 1.0 (0.4–2.2) | |
| Rare or never | 2 (3) | 57 (97) | 1.3 (0.3–5.7) | |
| Hygienic factors in past 12 mo | ||||
| Have skin contact with abscess | 10 (7) | 124 (93) | 2.3 (1.1–5.0) | |
| Get bug bites | 10 (4) | 229 (96) | 1.0 (0.5–2.2) | |
| Bite fingernails | 5 (4) | 134 (96) | 0.8 (0.3–2.2) | |
| Pick nose | 14 (6) | 240 (94) | 1.7 (0.8–3.8) | |
| Pick skin | 7 (5) | 123 (95) | 1.4 (0.6–3.3) | |
| Use public hot tub or sauna | 5 (7) | 67 (93) | 1.8 (0.7–4.7) | |
| Shave face | 20 (4) | 424 (96) | 1.4 (0.5–3.7) | |
| Shave head | 12 (8) | 141 (92) | 2.7 (1.3–6.4) | 2.1 (0.9–4.7) |
| Shave chest | 5 (10) | 46 (90) | 2.7 (1.1–6.9) | |
| Shave groin, genital, or buttock area | 10 (9) | 104 (91) | 2.8 (1.3–6.2) | 2.1 (0.9–6.7) |
| Drug use in past 12 mo | ||||
| Methamphetamine | 0 | 20 (100) | NC | |
| Cocaine or crack | 3 (3) | 89 (97) | 0.8 (0.2–2.5) | |
| Poppers or nitrites | 3 (5) | 53 (95) | 1.3 (0.4–4.3) | |
| Injected or skin-popped any drug | 0 | 13 (100) | NC |
*Values are no. (%) unless otherwise indicated. Boldface indicates significant results. MRSA, methicillin-resistant Staphylococcus aureus; IQR, interquartile range; NC, not calculated because there were insufficient events to calculate the relative risk; MSM, men who have sex with men; IDU, injection drug use; MSSA, methicillin-susceptible S. aureus; PCP, Pneumocystis pneumonia; TMP/SMX, trimethoprim/sulfamethoxazole. †p values are Wilcoxon rank-sum test results. ‡Sexual contact with a person known to be HIV-infected or at high risk for HIV infection (e.g., history of IDU or MSM). §Risk not specified or unknown (n = 152); other (n = 9) indicates transfusion (n = 4) or health care worker occupational exposure (n = 5). ¶Antibiotics with anti-staphylococcal activity used were fluoroquinolones, TMP/SMX, azithromycin, clarithromycin, mupirocin, cephalexin, vancomycin, linezolid, and ampicillin-clavulanate.