Methicillin-resistant Staphylococcus aureus in cystic fibrosis: how should it be managed?

Methicillin-resistant Staphylococcus aureus (MRSA) remains prevalent in people with cystic fibrosis (CF). As chronic infection is often associated with worse pulmonary outcomes, the organism is concerning to CF providers and patients. This review describes current epidemiology, our understanding of risk factors for MRSA infection, and relevant aspects of treatment with review of new and ongoing trials.

Prevalence ranges from a low of 3 to 4% in some European countries to a high of approximately 26% in the United States. Risk factors for chronic MRSA infection include patient-specific factors such as genotype, pancreatic insufficiency, diabetes and antibiotic use; however, warmer climate also contributes to increased MRSA rates in CF and non-CF. In addition to retrospective reviews, a few clinical trials are being conducted or have been performed showing the successful short-term eradication of incident MRSA. Chronic MRSA remains challenging to eradicate and antibiotics should be dosed to adjust for CF-specific pharmacokinetics.

As chronic MRSA will remain a long-term challenge to treat, ongoing effort should focus on the prevention of transmission with a need to better understand patient's environmental and modifiable risk factors. Early treatment appears successful; however, protocols to achieve long-term clearance are lacking.