MRSA carriage

Mulqueen et al¹ describe the prevalence of MRSA carriage among GPs in the West of Ireland and note accurately the lack of data available on prevalence rates of MRSA in the community. Having made the same observation, I conducted a study within a general practice community in rural northwest Ireland last year. All consecutive attendees at the surgery over a 2-week period in December 2006 were invited to participate until a sample of 114 was obtained. Data on previously identified risk factors for MRSA carriage, such as recent hospital admission, antibiotic use in the last 3–6 months,² and having a chronic disease,^2–4 was collected on participants and a single nasal swab was taken from the anterior nares. Only one case of MRSA carriage was identified giving a point prevalence of 0.9% (95% CI = 0.25% to 5.57%). That subject had none of the categorised risk factors. We did not test the GPs serving this area, but the setting of our study is very similar to your published study in which the nasal carriage rate among GPs was 7%.¹ In the literature there were three similar population studies to be found from the UK — all of which report a comparable prevalence figure. (0.8–1.5%)^3,5,6 If these two Irish studies tell us anything it is that we are more likely to convey MRSA to our patients than the other way around, whether this is from our high rate of carriage or our high rate of prescribing, we would do well to be constantly aware of our primary ethical principle and first do no harm.