Background: The epidemiology of MRSA infection in HIV positive population is not well characterized. We sought to analyze the trend of MRSA infection in HIV positive patients in recent years, and compare their clinical characteristics with HIV negative population.
Methods: Using Nationwide Inpatient Samples (NIS, 2005-2012), we identified hospitalized HIV (+) adults (age above 18 years) and those with invasive MRSA infection by ICD-9-CM codes. The prevalence trend of MRSA infection was analyzed. Using all HIV (+) patients and randomly selected 1% of HIV (-) patients in NIS 2012, the demographics, type of infection and comorbidities in those with MRSA infection were compared between HIV (+) and HIV (-) groups. Independent risk factors for MRSA infection were evaluated by Logistic regression.
Results: 1,963,800 HIV (+) hospitalizations were identified in 2005-2012. The prevalence of MRSA infection in HIV (+) hospitalizations was 2.7% (n=52,945), which was 2.5 times higher than HIV (-) hospitalizations (1.1%). In 8 years, the prevalence of MRSA infection in HIV (+) hospitalizations increased from 2.6% in 2005 to 3.0% in 2009, then decreased to 2.4% in 2012 (Fig 1). With the data in NIS 2012, including 214,710 in HIV (+) group and 303,430 in HIV (-) group, the rates of MRSA in skin and soft-tissue infections, surgical infections, bacteremia, septic arthritis, pneumonia and urinary tract infection were found significantly higher in HIV (+) group than HIV (-) group (Fig 2). The risk factors for MRSA infection in HIV (+) hospitalizations were male patients (OR=1.2), hemodialysis (OR=1.4), diabetes with complications (OR=1.5), illicit drug use (OR=1.3) and prolonged hospital stay (OR=2.3 and 3.4 for 8-21days and >21 days, respectively). These risk factors for MRSA infection were also found in HIV (-) hospitalizations. In HIV (+) hospitalizations, those with AIDS had a 1.5 times higher risk of MRSA infection than those without AIDS.
Conclusion: The prevalence of invasive MRSA infection in hospitalized HIV positive patients decreased in recent years, but it was always higher than HIV negative population. During hospitalization, when infection is suspected in HIV positive patients but their microbiologic data are not available yet, antibiotic with MRSA coverage should be considered.