Actinobacillus Actinomycetemcomitans Endocarditis

IN 1912, Kilinger first describedActinobacillus actinomycetemcomitansas a bacterial organism occurring in close association with active cases of actinomycosis. Thjøtta and Sydves in 1951 reported the first case of human infection in which this organism was the sole infecting agent.¹King and Tatum have reported cultural and serological studies onA actinomycetemcomitansidentified from blood cultures in 27 instances, but the sources of infection were not described.²A review of the literature has failed to reveal a case ofA actinomycetemcomitansendocarditis. It is our purpose to present such a case with bacteriologic and pathologic material and to reemphasize the similarity of this organism toHemophilus aphrophilus. Report of Case A 57-year-old Negro (0-14521) was admitted to the Ann Arbor Veterans Administration Hospital on June 11, 1964. Four months earlier he had begun experiencing fatigue, weakness, fever, and nocturnal diaphoresis. Hospitalization elsewhere revealed a hemoglobin level of