Risks for methicillin-resistant Staphylococcus aureus colonization or infection among patients with HIV infection

Area of Science:

• Infectious Diseases
• HIV/AIDS Research
• Microbiology

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses varying risks to individuals with HIV infection.
• The specific epidemiology of USA-300 community-acquired MRSA (CA-MRSA) in this population remains incompletely understood.

Purpose of the Study:

• To identify risk factors for MRSA colonization or infection in HIV-infected outpatients.
• To characterize the prevalence and risk factors for USA-300 CA-MRSA strains in this cohort.

Main Methods:

• Retrospective review of 900 HIV-infected outpatients from 2002-2007.
• Multivariate logistic regression (MLR) to determine MRSA risk factors.
• Pulsed-field gel electrophoresis (PFGE) for USA-300 strain identification.

Main Results:

• 8% (72/900) of HIV patients had MRSA colonization or infection.
• Past antibiotic exposure (OR 3.4) and nadir CD4 count <200 cells/µL (OR 2.5) were significant MRSA risks.
• Antiretroviral therapy (ART) use within the past year decreased MRSA risk (OR 0.16).
• 89% of identified strains were USA-300.
• Skin or soft tissue infection (SSTI) predicted USA-300 infection (OR 5.9).

Conclusions:

• Low CD4 count nadir (<200 cells/µL) and prior antibiotic exposure are key risks for MRSA in HIV patients.
• SSTI was the primary predictor for USA-300 infection, limiting broader predictive capabilities.
• ART use within the preceding year demonstrated a protective effect against MRSA colonization and infection.