‘Feral’ and ‘wild’-type methicillin-resistant Staphylococcus aureus in the United Kingdom
MILLER R., WALKER AS., KNOX K., WYLLIE D., PAUL J., HAWORTH E., MANT D., PETO T., CROOK DW.
<jats:title>SUMMARY</jats:title><jats:p>Circulation of methicillin-resistant <jats:italic>Staphylococcus aureus</jats:italic> (MRSA) outside hospitals could alter the impact of hospital-based control strategies. We investigated two groups of cases (each matched to controls with MRSA): 61 ‘community cases’ not in acute hospital in the year before MRSA isolation; and 21 cases with ciprofloxacin-sensitive (CipS) MRSA. Multi-locus sequence typing, <jats:italic>spa-</jats:italic>typing and Panton–Valentine leukocidin gene testing were performed and demographics obtained. Additional questionnaires were completed by community case GPs. Community cases comprised 6% of Oxfordshire MRSA. Three community cases had received no regular healthcare or antibiotics: one was infected with CipS. Ninety-one percent of community cases had healthcare-associated sequence type (ST)22/36; CipS MRSA cases had heterogeneous STs but many had recent healthcare exposure. A substantial minority of UK MRSA transmission may occur outside hospitals. Hospital strains are becoming ‘feral’ or persisting in long-term carriers in the community with regular healthcare contacts; those with recent healthcare exposure may nevertheless acquire non-hospital epidemic MRSA strains in the community.</jats:p>