Methicillin-resistant Staphylococcus aureus carriage in hospitalized chronic hemodialysis patients and its predisposing factors

There has been a paucity of literature on methicillin-resistant Staphylococcus aureus (MRSA) colonization in chronic hemodialysis patients who required admission. The purpose of this study is to determine the MRSA carriage rate in hospitalized chronic hemodialysis patients, to identify the risk factors, and assess the consequences of MRSA colonization. This was a retrospective study of hospitalized chronic hemodialysis patients at Khoo Teck Puat Hospital from July 1, 2010 to June 30, 2011. MRSA screening was done on the day of admission using culture method with MRSA select (Bio-Rad)(TM). The patients were divided into two groups: MRSA carriers and noncarriers. Demographic data, medical, and laboratory information was obtained via electronic medical record system. Outcome measures were infection rates during current hospitalization episode, frequency of hospitalization, and cumulative hospitalization days per year. Prevalence rate of MRSA colonization in hospitalized chronic hemodialysis patients was 15.1%, compared to all admitted patients (5.8%). Diabetes mellitus, Malay ethnicity, shorter hemodialysis duration and use of tunneled hemodialysis catheters were associated with MRSA colonization (P < 0.05). Relative risk of infection during the episode of admission among MRSA carriers was 3.2-fold compared to noncarriers. MRSA colonization rates tend to be higher in patients on hemodialysis for less than 3 years and it correlates with longer hospitalization after adjustment for other variables (P < 0.05). Patients on chronic hemodialysis requiring admission have higher rates of MRSA colonization. The risk factors of MRSA carriers and the correlation of MRSA rates to longer hospitalization suggest its nosocomial origin in this group of patients.