Endocarditis epidemiology and demographics

Incidence
The incidence of infective endocarditis is approximately 2-4 cases per 100,000 persons per year worldwide. This rate has not changed in the past 5-6 decades.

Age
Infective endocarditis may occur in a person of any age. The frequency is increasing in elderly individuals, with 25-50% of cases occurring in those older than 60 years of age.

Gender
Infective endocarditis is 3 times more common in males than in females.

Risk Factors for Endocarditis
Adults and children with underlying cardiac conditions placing them at highest risk for adverse outcomes of infective endocarditis (IE) including those with:
 * Prosthetic cardiac valve or prosthetic cardiac valve repair
 * Previous infective endocarditis
 * Congenital heart disease (CHD) associated with
 * Unrepaired cyanotic CHD, including palliative shunts and conduits
 * Completely repaired congenital heart defect with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure
 * Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization)
 * Cardiac transplantation patients who develop cardiac valvulopathy

What is the incidence among patients who do not use illicit drugs and have a fever in the emergency room?
There is less than a 5% chance of occult endocarditis. Mellors in 1987 found no cases of endocarditis nor of staphylococcal bacteremia among 135 febrile patients in the emergency room. The upper confidence interval for an incidence of 0% among 135 patients is 5%, statistically there is up to a 5% chance of endocarditis among these patients. In contrast, Leibovici found that among 113 non-selected adults admitted to the hospital because of fever there were two cases (1.8% with 95%CI: 0% to 7%) of endocarditis.

What is the incidence among patients who do use illicit drugs and have a fever in the emergency room?
There is about a 10% to 15% prevalence of endocarditis. This estimate is not substantially changed by whether the doctor believes the patient has a trivial explanation for their fever. Weisse found that 13% of 121 patients had endocarditis. Marantz also found a prevalence of endocarditis of 13% among such patients in the emergency room with fever. Samet found a 6% incidence among 283 such patients, but after excluding patients with initially apparent major illness to explain the fever (including 11 cases of manifest endocarditis), there was a 7% prevalence of endocarditis.

What is the incidence among patients with staphylococcal bacteremia (SAB)
One study found a 29% prevalence of endocarditis in community-acquired SAB versus 5% in nosocomial SAB. However, only 2% of strains were resistant to methicillin and so these numbers may be low in areas of higher resistance.