**2. Epidemiology of CNE**

The epidemiology of infective endocarditis, and hence CNE, has changed over the last five decades [5, 10]. Patients are generally older and male, with greater numbers of hospital associated cases, and with indwelling devices such as catheters, pacemakers and prosthetic valves. Accordingly the numbers of cases of infective endocarditis with *Staphylococcus aureus*, coagulase-negative *Staphylococci* and *Enterococci* have increased. With the advent of novel diagnostic methods (PCR-based testing), the prevalence of CNE may have decreased to 14.2% [5] in the last decade, but other reviews indicate otherwise [10]. Specific aspects of the patient's medical history may provide "epidemiological clues" (Table 6 in Ref. [1]) to the microbiological cause. Military personnel have some higher risk of CNE due to *C. burnetti* for example [11].
