Community-acquired methicillin-resistant Staphylococcus aureus: prevalence and risk factors.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to most antibiotics and is an important pathogen of nosocomial infections. Colonization with MRSA is no longer limited to hospitalized patients or persons with predisposing risk factors and at present there are several strains of community-acquired MRSA (CA-MRSA). Objectives: The aim of this study was to determine the prevalence of community-acquired methicillin-resistant Staphylococcus aureus and also the colonization-associated risk factors. Method: This cross-sectional study was conducted through random sampling of 1083 patients admitted to Qazvin hospitals from 2004 to 2006. Nasal swabs were obtained at admission and cultured on mannitol salt agar. Oxacillin-screening plate was used to demonstrate methicillinresistance strains of SA (according to NCCLS guidelines). Demographic and specific information were collected by questionnaire. Data were analyzed by Chi square test. Results: The participants’ age group ranged between 2 to 94 years (mean 42.24) among those, 468 (43.2%) were males and 615 (56.8%) females with 613 (56.6%) living in urban areas. Of 1083 individuals, 56 (5.2%) were SA carrier, 51 (4.7%) colonized with MSSA and 5(0.5%) with MRSA strains. Several factors such as occupation, family size, previous hospitalization, history of antibiotic therapy within the previous 2 months, and also the presence of chronic diseases were assessed, however, no significant relationship with MRSA colonization was found (p> 0.05). Conclusion: This study confirmed the presence of CA-MRSA in Qazvin. There was no significant relationship between the prevalence of CA-MRSA strains and the risk factors.