**23. Epidemiology**

In 1978, MacMillan et al. (MacMillan et al., 1978) studied 60 patients with SPE over a 5-year period and reported that most of SPE cases occurred in drug users. Intravenous drug abuse (IVDA-78%) and tricuspid endocarditis were identified as the embolic source in 53% of these IVDA cases (fig 2b) (MacMillan et al., 1978). However, the epidemiology and outcome of patients with SPE have changed over the past 30 years with the increased use of long term indwelling catheters and devices (pacemakers, prosthetic vascular devices) and also increase in the number of immune-compromised patients. The predominant cause of SPE in the current era is infections related to intravascular devices/catheters or soft-tissue infections. Its incidence is declining among IVDA presumably due to greater needle hygiene (Fig 2a) (Cook et al., 2005)**.** Intravascular devices are a common cause of local site infection and cause up to 50% of the nosocomial bacteremias. Central venous catheters account for 80-90% of these infections.

In a large series of postmortem examinations in Japan, a total of 11,367 PE cases were identified from 396,982 postmortem examinations. In this study, the incidence of septic PE was found to be 2.2% (Sakuma et al., 2007).
