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.

Keywords: Endocarditis, Bacterial, Staphylococcus aureus, Methicillin resistance, Cross-infection, Australia