The epidemiological profile of infective endocarditis (IE) has changed dramatically over the last few years.¹ Once a disease affecting young adults with previously well-identified valve disease—mostly rheumatic disease—IE is now affecting older patients, a significant proportion of whom has no previously known valve disease and develop IE as the result of healthcare associated procedures.²

A CHANGING EPIDEMIOLOGY

Until the end of the 1970s, rheumatic valvulopathies and congenital cyanotic cardiopathies were the two most frequent predisposing factors for IE. Then, a few years after the effective eradication of rheumatic fever, post-rheumatic valvulopathies gradually disappeared. However, other predisposing factors emerged, such as intravenous drug use, valve prostheses, degenerative valve sclerosis, and invasive procedures at risk for bacteraemia, which resulted in nosocomial and health care-associated endocarditis.³ These changes had at least two consequences: (1) the absence of a reduction in the incidence of IE; and (2) major changes in the microbiological profile of IE. In a meta-analysis of 26 articles published between 1993 and 2003, including a total of 3784 episodes of IE, Moreillon and Que showed that oral streptococci (also known as viridans streptococci) are now only second to staphylococci as the leading cause of IE.¹ As a result, it is now critical to regard the epidemiology of IE as a set of various clinical situations sometimes differing greatly from one another. Thus, at least five categories of IE have been identified: native valve endocarditis; prosthetic valve endocarditis; endocarditis in intravenous drug users (IVDUs); nosocomial endocarditis; and healthcare-related endocarditis resulting from invasive procedures such as endovascular investigations, haemodialysis, and implanted endovascular or intracardiac devices. Significant geographical variations have also been shown, with the highest increases in the rate of staphylococcal endocarditis being reported in the United States.⁴ In a prospective study of 1779 cases of IE collected in 16 countries, …