Methicillin Resistant Staphylococcus aureus Endocarditis in an Australian Tertiary Hospital: 1991-2006

Background: Methicillin resistant Staphylococcus aureus (MRSA) endocarditis is increasing in frequency and has a high mortality. This condition has not been specifically described in an Australian population previously. Aim: To describe the characteristics, management and outcomes of patients with MRSA endocarditis in an Australian hospital and identify trends in this group over 16 years. Methods: Retrospective case series of MRSA endocarditis patients between 1991 and 2006. Results: Between 1991 and 2006, 27 patients were managed for MRSA endocarditis. This group consisted of 18 males (67%). The median age was 64 years. Infection was related to a prosthetic valve or annular ring in 10 patients (37%). The most common comorbidities were diabetes mellitus 8 (30%) and malignancy 8 (30%). Nosocomial acquisition occurred in 16 (59%), non-nosocomial healthcare associated acquisition in 10 (37%) and community acquisition in 1 (4%). Management was with a single antimicrobial agent in 5 (19%) and combination antimicrobial therapy in 22 (81%). Surgery was undertaken in 16 patients (59%). The mortality was 66%. Over this time there was increased non-nosocomial acquisition and presentations to non-tertiary hospitals. There was no clear improvement in survival over the 16 years. Conclusion: In this Australian setting, MRSA endocarditis was mostly nosocomial or healthcare associated. Common characteristics were older patients with multiple co-morbidities. Despite high rates of combination antibiotic therapy and surgery, mortality was very high. There is a need for randomised comparative antibiotic studies. Crown