Mortality after infection with methicillin-resistant Staphylococcus aureus (MRSA) diagnosed in the community

We used the United Kingdom's General Practice Research Database (GPRD) to form a cohort of all patients with MRSA diagnosed in the community from 2001 through 2004 and up to ten patients without an MRSA diagnosis. The latter were frequency-matched with the MRSA patients on age, GPRD practice and diagnosis date. All patients were older than 18 years, had no hospitalization in the 2 years prior to cohort entry and medical history information of at least 2 years prior to cohort entry. The cohort was followed up for 1 year and all deaths and hospitalizations were identified. Hazard ratios of all-cause mortality were estimated using the Cox proportional hazards model adjusted for patient characteristics.The cohort included 1439 patients diagnosed with MRSA and 14,090 patients with no MRSA diagnosis. Mean age at cohort entry was 70 years in both groups, while co-morbid conditions were more prevalent in the patients with MRSA. Within 1 year, 21.8% of MRSA patients died as compared with 5.0% of non-MRSA patients. The risk of death was increased in patients diagnosed with MRSA in the community (adjusted hazard ratio 4.1; 95% confidence interval: 3.5–4.7).MRSA infections diagnosed in the community are associated with significant mortality in the year after diagnosis.Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly implicated in potentially lethal hospital-acquired infections [1,2]. Some of the MRSA strains that are found in patients in the community have been acquired during hospitalization or a visit to a hospital. However, MRSA strains likely originating outside of hospitals and different from those found in hospitals have been identified [3-5]. People who are infected by MRSA in the community have different risk factors than those infected in hospitals [1,2], particularly as common risk factors in hospitals may be rare or absent in the community.While hospital-acquired MRSA infections can be fatal [1,2], cases of severe and life-threatening MRSA infection