The modern epidemiology of infective endocarditis

The contemporary picture of infective endocarditis (IE) commonly affects elderly patients with extensive health care contact, often involving prosthetic valves, cardiac devices and is caused by Staphylococci, in particular, Staphylococcus aureus predominates. Health care association (HCA) now accounts for about half of all cases of IE; in particular those caused by S. aureus, coagulase negative Staphylococci and involving prosthetic valves and cardiac devices. Predisposing factors include intravascular devices, hemo-dialysis and the timing of procedures such as implantation of cardiac devices. There is now significant evidence that a high proportion of patients with Staphylococcus aureus bacteremia (SAB) in fact have IE and that this can only reliably be detected by performing transoesophageal echocardiography (TOE). Health care associated infection (HCA) is increasingly recognised and may be potentially preventable through meticulous attention to asepsis, intravascular catheter device care and in selected populations, with topical skin asepsis or antibiotic prophylaxis. This requires further prospective controlled studies. Cardiac devices are increasingly implanted worldwide and carry an early infection risk related to the implantation procedure, but also longer term through inter-current blood stream infections. The potential for prevention by antibiotic and other modifiable risk factors requires further study. Increasingly other organisms such as Enterococci and Candida species fungal infections are being reported. Novel anti-fungal agents such as Caspofungin and the other echinocandins have improved the outcome for patients with fungal IE who are deemed unsuitable for surgical intervention, however larger trials are needed. Despite increased age and co-morbidities surgical treatment such as valve replacement and cardiac device removal is performed successfully and increasingly in over half of all cases of IE. Parenteral antibiotic therapy is increasingly being delivered safely at home (HITH) in stable and carefully selected patients. A detailed economic evaluation of home care would be of further value. Over the last 12 years the research that I and my collaborators have led has significantly contributed to the medical literature demonstrating significant changes in the epidemiology of IE in the early 21st century. We have identified key patient risk factors in the health care setting which will better enable clinicians worldwide to better manage and prevent IE. There needs to be closer attention to aseptic technique, intravascular device care and early removal. We have emphasised the increasing role of novel antimicrobials to optimise treatment in drug resistant infections and finally the importance of early definitive surgery and device removal in complex cases.