Nasal MRSA Carriage Predicts Worse Outcomes in Hemodialysis Patients

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Even without clinical signs of infection, hemodialysis patients who are methicillin-resistant Staphylococcus aureus (MRSA) carriers are at increased risk of death, reports a study in BMC Nephrology.

The prospective cohort study included 289 hemodialysis outpatients at an urban dialysis unit. All underwent nasal swabs for MRSA culture at admission to the unit, after transfer from another unit, or on readmission after a hospital stay. Patients found to be nasal MRSA carriers were kept in a separate ward and treated with nasal muciprocin; appropriate treatments for extranasal (throat and skin) MRSA colonization were used as well. Clinical characteristics and outcomes were compared for MRSA carriers versus noncarriers.

Nasal MRSA carriage was identified in 11.7 percent of patients. About one-third of nasal MRSA carriers also had extranasal colonization. Patients with a history of cancer and those with increased comorbidity were more likely to be nasal MRSA carriers. Traditional MRSA risk factors were not significant, nor were markers of inflammation or malnutrition.

During follow-up, death occurred in 55.9 percent of patients whose test results for MRSA were positive versus 37.4 percent of MRSA-negative patients. The mortality difference was significant on Kaplan-Meier analysis. Muciprocin treatment eradicated nasal MRSA colonization in 73.5 percent of patients. For patients in whom eradication therapy was unsuccessful, all-cause mortality exceeded 85 percent.

Nasal MRSA carriage is a known risk factor for bacteremia and death in various patient groups. There is ongoing controversy regarding its clinical impact on patients receiving long-term hemodialysis.

About one of eight hemodialysis patients may be nasal MRSA carriers, the new study suggests. These patients are at increased risk of death during follow-up, especially if muciprocin is not effective in eradicating MRSA. The authors call for further study of nasal MRSA colonization as an independent outcome predictor in hemodialysis patients [Schmid H, et al. Persistent nasal methicillin-resistant staphylococcus aureus carriage in hemodialysis outpatients: a predictor of worse outcome. BMC Nephrol 2013; 14:93].