Methicillin-resistant Staphylococcus aureus nasal carriage among patients receiving hemodialysis: comparison between a local hospital and a medical center in Taiwan

Background: Staphylococcus aureus, particularly methicillin resistant (MRSA), is a common pathogen among patients receiving hemodialysis. To understand MRSA carriage rate among these patients in different hospital levels, we conducted this study. Materials and Methods: From January 2011 to June 2011, two nasal samplings with a 3-month interval were obtained from 161 patients (totally 265 samplings, both surveys for 104 patients) who undergoing hemodialysis in a medical center, and 135 patients (totally 264 samplings, both surveys for 129 patients) in a local hospital in Taiwan and sent for the detection of MRSA. Once MRSA carriage was identified, decolonization procedures were administered. All 161 patients in the medical center were observed if MRSA infections occurred during the study period. Results: In the first sampling, the nasal MRSA colonization rate was 2.3% for the local hospital and 5.2% for the medical center. In the second sampling, the colonization rate was 4.4% and 3.4%, respectively. No significant difference was found between both hospitals, as well as both batches in term of nasal MRSA carriage rate. No significant associated risk factor for MRSA carriage was identified, either. 16 (80%) of the 20 MRSA isolates carried either type IV or VT staphylococcal chromosome cassette (SCCmec) and 14 isolates were local community strains, belonging to sequencing type 59 linage. One colonized patient failed decolonization after the first sampling but was successfully decolonized after second sampling; others were successfully decolonized. Within the 6-month study period, two patients (1.24%) in the medical center, one with MRSA colonization (9.1%), developed MRSA infection. Conclusion: A substantial proportion of patients receiving hemodialysis in Taiwan had MRSA colonization, mostly community strains, but no additional risk factors for MRSA acquisition was identified. The carriage rate was no significant difference between those in the medical center and local hospital.