بررسي شيوع كلونيزاسيون استافيلوكوك اورئوس مقاوم به متي سيلين اكتسابي از جامعه CA-MRSA و عوامل همراه آن در بيماران مراجعه كننده به اورژانس بيمارستان لقمام حكيم

prevalance and risk assessment of ca-mrsa nasal colonization in patients of loghman hospital Tehran. iran

Background:Community-associated methicillin-resistant staphylococc us aureus (CA-MRSA) is a serious pathogen and its nasal carriage is a risk factor for subsequent infection s. This study aimed to determin e the prevalence of and risk factors for CA-MRSA coloni zation at the time of hospital admission in our community. Methods: During 2007, patients admitted to the emergency department of Loghman Hakeem hospital were intervi ewed and anterior nares cultures were obtained within 24 hours of admission. A cross-sectional study and antibiotic susceptibility tests (E-Test) were performed. A positive culture of MRSA with in 24 hour s of admission was considered as CA-MR SA. Chi-square test was performed to assess associations between culture results and the studied risk factors, using SPSS version 15. Findings: 56 (14%) and II (2.7%) of 400 patients had a nare culture positive for staphylococcus aureus and MRSA, respectively. HIV infection (P = .00 I ), nursing home residence (P = .033) and nasal anatomic abnormalities (p= .033) had significant association with CA-MRSA cultures. However, in logistic regression , no statistically significant association was found . 45% of MRSA cultures showed induced resistance to clindamycin on D-test. On tigacylin e E-test, based on a 1211g/ml cutoff for susceptibility, 6 (54 .5%) showed resistance . Conclusion: Our study showed CA-MRSA prevalence to be 2.7% and did not demonstrate any association between recent hospitalization , antibiotic use and IV drug abuse with CA-MRSA carriage status unlike other studies . This may have been a result of CA-MRSA low prevalen ce and a small sample size. We recommend a study with a larger sample size for appropriate evaluation of risk factors.