Comparison of subsequent infection in methicillin-resistant Staphylococcus aureus nasal carriers between ST72 community-genotype and hospital genotypes: a retrospective cohort study

Abstract

Abstract Background Carriage of methicillin-resistant Staphylococcus aureus (MRSA) is an important risk factor of subsequent infection. The purpose of our study was to compare the rates of subsequent infection among newly-admitted patients carrying MRSA between community-genotype and hospital-genotypes Methods In this retrospective cohort study, we compared the rates of subsequent MRSA infection, time to subsequent infection and mortality in the following 6 months between the community-genotype ST72 MRSA cohort and the hospital-genotypes ST5 / ST239 MRSA cohort. Results We identified 198 patients carrying ST72 and 156 patients carrying ST5 or ST239. There was no difference in the rates of subsequent infection between ST72 cohort and ST5 / ST239 cohort (13.1% vs. 12.8%; P = 0.931). The median time to development of subsequent infection was not significantly different (27 days vs. 88 days; P = 0.0877). The Kaplan-Meier method showed no difference in the cumulative rate of being free of subsequent infection between the cohorts (P = 0.9209). Overall mortality rates at 6 months did not differ (1.5% vs. 1.9%; P = 1.000) Conclusions We found no evidence that rates of subsequent MRSA infection were different between newly-admitted patients carrying community-genotype ST72 MRSA and those whom carrying hospital-genotypes ST5 or ST239 MRSA.

Keywords

• Genotype
• Kaplan-meier estimate
• Methicillin-resistant Staphylococcus aureus
• Cohort study
• Carrier state