Open Access Research

Prevalence of and risk factors for MRSA colonization in HIV-positive outpatients in Singapore

Win M Kyaw1*, Linda K Lee1, Wong C Siong2, Angela Chow L Ping1,2,3, Brenda Ang4 and Yee S Leo4,5

Author Affiliations

1 Department of Clinical Epidemiology, Communicable Disease Centre, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore

2 Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore

3 Department of Epidemiology, School of Public Health, University of California Los Angeles, Los Angeles, USA

4 Department of Infectious Diseases, Communicable Disease Centre, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore

5 Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore

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AIDS Research and Therapy 2012, 9:33 doi:10.1186/1742-6405-9-33

Published: 6 November 2012

Abstract

Background

Whilst there have been studies on the risks and outcomes of MRSA colonization and infections in HIV-positive patients, local data is limited on the risk factors for MRSA colonization among these patients. We undertook this study in a tertiary HIV care centre to document the risk factors for colonization and to determine the prevalence of MRSA colonization among HIV-positive outpatients in Singapore.

Methods

This was a cross-sectional study in which factors associated with MRSA positivity among patients with HIV infection were evaluated. A set of standardized questionnaire and data collection forms were available to interview all recruited patients. Following the interview, trained nurses collected swabs from the anterior nares/axilla/groin (NAG), throat and peri-anal regions. Information on demographics, clinical history, laboratory results and hospitalization history were retrieved from medical records.

Results

MRSA was detected in swab cultures from at least 1 site in 15 patients (5.1%). Inclusion of throat and/or peri-anal swabs increased the sensitivity of NAG screening by 20%. Predictors for MRSA colonization among HIV-positive patients were age, history of pneumonia, lymphoma, presence of a percutaneous device within the past 12 months, history of household members hospitalized more than two times within the past 12 months, and a most recent CD4 count less than 200.

Conclusions

This study highlights that a proportion of MRSA carriers would have been undetected without multiple-site screening cultures. This study could shed insight into identifying patients at risk of MRSA colonization upon hospital visit and this may suggest that a risk factor-based approach for MRSA surveillance focusing on high risk populations could be considered.

Keywords:
Methicillin-resistant Staphylococcus auerus; HIV; Risk factors; Colonization