Risk factors for colonization or infection due to methicillin-resistant Staphylococcus aureus in HIV-positive patients: a retrospective case-control study.

Objective: To determine the risk factors for colonization or infection with methicillin-resistant Staphylococcus aureus in human immunodeficiency virus (HIV)-infected patients.

Design: Retrospective matched-pair case-control study.

Setting: Continuity clinic and inpatient HIV service of a university medical center.

Population: Patients with HIV infection from the general population of eastern and coastal Texas and from the Texas Department of Criminal Justice.

Data Collection: Patient charts and the AIDS Care and Clinical Research Program Database were reviewed for the following: age, race, number of admissions, total hospital days, presence of a central venous catheter, serum albumin, total white blood cell count and absolute neutrophil count, invasive or surgical procedures, any cultures positive for S. aureus, and a history of opportunistic illnesses, diabetes, or dermatologic diagnoses. Data also were collected on the administration of antibiotics, antiretroviral therapy, steroids, cancer chemotherapy, and subcutaneous medications.

Results: In the univariate analysis, the presence of a central venous catheter, an underlying dermatologic disease, lower serum albumin, prior steroid therapy, and prior antibiotic therapy, particularly antistaphylococcal therapy or multiple courses of antibiotics, were associated with increased risk for colonization or infection with methicillin-resistant S. aureus. Multivariate analysis yielded a model that included presence of a central venous catheter, underlying dermatologic disease, broad-spectrum antibiotic exposure, and number of hospital days as independent risk factors for colonization or infection with methicillin-resistant S. aureus.

Conclusions: In our HIV-infected patient population, prior hospitalization, exposure to broad-spectrum antibiotics, presence of a central venous catheter, and dermatologic disease were risk factors for acquisition of methicillin-resistant S. aureus.