Prevalence and risk assessment of CA-MRSA nasal colonization in patients of loghman hospital Tehran, Iran

ABSTRACT

Community-associated methicillin-resistant staphylococcus aureus [CA-MRSA] is a serious pathogen and its nasal carriage is a risk factor for subsequent infections. This study aimed to determine the prevalence of and risk factors for CA-MRSA colonization at the time of hospital admission in our community. During 2007, patients admitted to the emergency department of Loghman Hakeem hospital were interviewed 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 within 24 hours of admission was considered as CA-MRSA. Chi-square test was performed to assess associations between culture results and the studied risk factors, using SPSS version 15. 56 [14%] and 11 [2.7%] of 400 patients had a nare culture positive for staphylococcus aureus and MRSA, respectively. HIV infection [P = .001], 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 tigacyline E-test, based on a 12|microgram/ml cutoff for susceptibility, 6 [54.5%] showed resistance. 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 prevalence and a small sample size. We recommend a study with a larger sample size for appropriate evaluation of risk factors