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

Abstract

<p>Abstract</p> <p>Background</p> <p>Outbreak reports suggest that community-acquired methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) infections can be life-threatening. We conducted a population based cohort study to assess the magnitude of mortality associated with MRSA infections diagnosed in the community.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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).</p> <p>Conclusion</p> <p>MRSA infections diagnosed in the community are associated with significant mortality in the year after diagnosis.</p