Nasal carriage of meticillin resistant Staphylococcus aureus: the prevalence, patients at risk and the effect of elimination on outcomes among outclinic haemodialysis patients.

ABSTRACT

OBJECTIVE: Haemodialysis (HD) patients with meticillin-resistant Staphylococcus aureus (MRSA) infections face high morbidity and mortality. Nasal carriage of Staphylococcus aureus is known to play an important role as an endogenous source for HD-access-related infections that contribute significantly to morbidity, mortality and cost of end-stage renal disease (ESRD) management. This prospective investigation in regular out-clinic haemodialysis patients was undertaken to estimate the prevalence of S.aureus nasal carriage, to define patient groups at risk and to evaluate the effect of elimination on outcomes among outclinic haemodialysis patients. METHODS: 136 HD patients without signs of overt clinical infection (48 women, 88 men, age 22-88 years) were screened at least twice for the nasal carriage for meticillin-susceptible SA (MSSA) or meticillin-resistant SA (MRSA). Nasal carriage of S. aureus was related to demographic (age, gender, duration on HD), comorbidity (diabetes, malignancy) and exposure to health care (dialysis staff, hospitalisation). Nasal carriers for MRSA received standardized mupirocin therapy and were followed up for elimination and infections for 1 year. RESULTS: The prevalence of nasal carriage for staphylococcus aureus was 53 % (41 % MSSA, 12 % MRSA). Compared with patients showing no colonization or with MSSA carriers, the 16 patients with nasal carriage for MRSA were older and more likely to have acquired the bacteria while hospitalised. Genotyping of MRSA isolates revealed different strains in patients and care-providers. Mupirocin eliminated MRSA in all patients, none of these patients experienced an infection caused by staphylococcus aureus, confirming the known value of MRSA elimination from other studies. CONCLUSIONS: Elderly patients hospitalised for surgery constitute a high risk group for nasal carriage for MRSA. Early diagnosis may help prevent clinically relevant infection. Elimination of colonization by mupirocin appears to be an attractive preventive strategy.