An RCT of mupirocin versus medical grade honey to eradicate nasal MRSA. Research methodology and interim findings.

Background: In the European Union (EU), up to 70% of invasive S. aureus infections are methicillin resistant Staphylococcus aureus (MRSA) and in Ireland this is 21.5% (2014). Eradicating MRSA from the nose is important in... [ view full abstract ]

Background: In the European Union (EU), up to 70% of invasive S. aureus infections are methicillin resistant Staphylococcus aureus (MRSA) and in Ireland this is 21.5% (2014). Eradicating MRSA from the nose is important in preventing MRSA infection and current strategies rely heavily on mupirocin for nasal decolonisation. However, increasing mupirocin resistance restricts the use of this agent and topically applied medical grade honey (MGH) may be a potential alternative.
Aims: To compare through a randomised control trial (RCT), mupirocin and MGH to eradicate nasal MRSA. To determine and evaluate mupirocin susceptibility of MRSA isolates from individual patients at specific time periods.
Methods: A single-blind, single centre RCT is being conducted. The Phoenix® system was used for the initial identification of MRSA isolates followed by a gradient MIC E-test (Biomerieux®) for testing mupirocin susceptibility. Sample size calculation indicated that 188 pts in two equal groups would be required for a power of 80% with a significance level of 0.05. Consenting newly identified MRSA positive patients with nasal colonisation are being recruited.
Results: Over 50 patients have been enrolled so far, of which 19 are included in this interim review (9 mupirocin, 10 MGH). Six patients (67%) were successfully decolonised using mupirocin. Of the three patients with persistent MRSA, one isolate had high level mupirocin resistance. Four of ten patients (40%) were successfully decolonised using MGH; mupirocin susceptibilities were unchanged in the six isolates in those persistently colonised with MRSA. No serious adverse events occurred.
Conclusion: Interim analysis indicates successful nasal decolonisation may be possible with MGH. MRSA colonising strains do not vary over time.