Influence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage on MRSA bloodstream infections among patients on chronic hemodialysis

Background

Methicillin-resistance Staphylococcus aureus (MRSA) nasal carriage plays a key role in the pathogenesis of MRSA infections in hemodialysis patients. Our study was designed to evaluate the prevalence of MRSA nasal carriage in patients on chronic hemodialysis and its influence on development of MRSA bloodstream infections.

Methodology

Ours is a 12-month prospective observational study. A total of 50 patients who are on chronic maintenance hemodialysis were enrolled in this study. Prevalence of MRSA nasal carriage was studied using nasal swabs collected from the anterior nares. Swabs were inoculated on to Mannitol Salt Agar and HiCrom agar. Bactec blood culture was used to detect MRSA bloodstream infections.

Results

Staphylococcus aureus (S. aureus) nasal carrier state was detected 62% of patients. 83.87% of these S. aureus nasal carriers were found to be having MRSA. The incidence of MRSA bloodstream infections was 1.54 episode per 100 patient-months. MRSA bloodstream infection rates were significantly higher among MRSA nasal carriers as compared to non-MRSA carriers (p < 0.001). Low hemoglobin levels were significantly more among MRSA positive nasal carriers as compared to non-MRSA nasal carriers.

Conclusion

This study reveals that MRSA nasal carriage is more prevalent among hemodialysis patients and it is an independent risk factor for the development of MRSA bloodstream infections. Early prevention and treatment of MRSA nasal carriage in hemodialysis patients may prevent MRSA bloodstream infections in hemodialysis patients.