Methicillin-resistant Staphylococcus aureus: prevalence of and risk factors associated with colonization of patients on admission to the Teaching hospital, Karapitiya

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) causes a substantial burden of community-acquired and nosocomial infection. Prior colonization with MRSA is a recognized risk factor for MRSA infection. The study aimed to assess the prevalence of and risk factors for MRSA colonization at admission to surgical, medical and orthopaedic wards of Teaching Hospital, Karapitiya, Sri Lanka. From September 2016 to March 2017, consecutive patients admitted to orthopaedic wards and every fifth patient admitted to medical and general surgical wards were enrolled. A nasal swab was collected from the anterior nares within 24 hours of admission and tested using standard microbiologic procedures. Clinical and demographic data were collected. A total of 502 patients were enrolled, including 152 medical, 201 general surgical, and 149 orthopaedic patients. The median age was 45 years (range 3- 85 years) and 58% of patients were male. At admission, 31 (6.2%) were colonized with MRSA. Colonization prevalence was higher in orthopaedic (18, 12.1%) compared to medical (6, 4.0%) and general surgical (7, 3.5%) patients, p=0.002. Patients colonized with MRSA on admission were more likely to be children <18 years (29% vs 8.7%, p=0.0003) and male (80.6% vs 56.5%, p=0.008). Hospitalization, history of surgery, antibiotic intake, and healthcare-related employment within the previous six months were not associated with MRSA colonization on admission. Use of public swimming pools, history of incarceration, and use of illicit drugs were significantly associated with MRSA colonization. MRSA colonization was highest among orthopaedic patients. Improved infection control efforts and targeted decolonization may help decrease MRSA colonization.