Endocarditis with Negative Blood Cultures

Abstract

The blood culture is the single most important laboratory test in the diagnosis of infective endocarditis. Bacteria are discharged from endocardial vegetations and cleared from the blood at a relatively constant rate,¹ which explains the continuous bacteremia and the high percentages of positive blood cultures reported in the literature. A study at New York Hospital—Cornell Medical Center reviewed 206 cases of culture-proved infective endocarditis that occurred from 1944 through 1960.² The authors demonstrated that in the absence of antimicrobial therapy during the two weeks before hospitalization, 95 percent of 789 blood cultures were positive for the causative microorganism. The first . . .