In developed countries, the incidence of endocarditis ranges from 2.6 to 7.0 cases per 100,000 population per year. Predisposing conditions include congenital heart disease, illicit IV drug use, degenerative valve disease, intracardiac devices, and health care-associated infections. The incidence of endocarditis is increased among the elderly and among pts with prosthetic heart valves. The risk of endocarditis is greatest during the first 6 months after valve replacement.