934. Incidence of Skin and Soft-tissue Infection in People Living With HIV in a Large Urban Public Health Care System in Houston, Texas, 2009–2014

Abstract

BackgroundSkin and soft-tissue infections (SSTIs) disproportionately impact patients with HIV. Recent declines have been noted in the incidence of SSTIs in the non-HIV population. We set out to study the epidemiology and microbiology of SSTIs in a population of 8,597 patients followed for HIV primary care in a large urban county system from January 1, 2009 to December 31, 2014.MethodsSSTIs were identified from the electronic medical record (EMR) by the use of ICD-9 billing codes. Charts were reviewed to confirm the diagnosis of acute SSTI and abstract culture and susceptibility data. We calculated yearly SSTI incidence using Poisson regression with clustering by patient.Results2202 SSTIs were identified. Of 503 (22.8%) cultured SSTIs, 332 (66.0%) included S. aureus as a pathogen, of which 287/332 (86.4%) featured S. aureus as the sole pathogen. Of S. aureus isolates with susceptibilities, 231/331 (69.8%) were methicillin-resistant, and the proportion did not vary by year (P = NS).The observed incidence of SSTI was 78.0 per 1,000 person-years (95% CI 72.9–83.4) and declined from 96.0 infections per 1,000 person-years in 2009 to 56.5 infections per 1,000 person years in 2014 (P < 0.001). Other significant predictors of SSTI incidence in both univariate as well as multivariate analysis included CD4 count, viral load, and being a Spanish-speaking Hispanic.ConclusionAlthough SSTI rates in a large urban HIV-infected outpatient cohort declined approximately 40% between 2009 and 2014, SSTIs remain a significant problem.Figure 1.SSTI incidence per 1000 person-years, 2009–2014Table 1:Univariate and Multivariate Poisson Regression ResultsFactorUnivariate IRR (95% CI)Multivariate IRR (95% CI)Male gender1.06 (0.92–1.22)–MSM1.09 (0.95–1.25)–Race/ethnicityWhite/Asian/otherRefRefNon-Hispanic African-American0.92 (0.76–1.11)0.86 (0.71–1.04)English-speaking Hispanic0.88 (0.69–1.12)0.88 (0.69–1.12)Spanish-speaking Hispanic0.46¥ (0.36–0.60)0.48¥ (0.37–0.62)CD4 count (cells/µL)100+RefRef50–1001.56* (1.19–2.04)1.23 (0.93–1.62)<502.28¥ (1.80–2.90)1.49* (1.16–1.92)Viral load (copies/mL)<1,000RefRef1,000+2.17¥ (1.91–2.46)1.90¥ (1.66–2.19)Year2009RefRef20100.89 (0.75–1.06)0.92 (0.78–1.10)20110.90 (0.75–1.07)0.96 (0.80–1.15)20120.91 (0.76–1.09)0.99 (0.83–1.19)20130.71¥ (0.58–0.85)0.77* (0.64–0.93)20140.59¥ (0.49–0.71)0.65¥ (0.54–0.79)*P < 0.01. ¥ P < 0.001.Disclosures C. Arias, Merck & Co., Inc.: Grant Investigator, Research support. MeMed: Grant Investigator, Research support. Allergan: Grant Investigator, Research support