Haemophilus parainfluenza--an uncommon cause of septicemia and endocarditis

6 cases of endocarditis and 1 of septicemia caused by Haemophilus parainfluenzae have been observed in our hospital from 1970 to 1977, as against no case from 1957 to 1969. The mean age of the patients was 46 years. The clinical picture did not differ from that seen in cases of septicemia and endocarditis from other cases. In 4 cases no underlying heart disease was known. In 2 of them, endocarditis developed in the mitral and in 1 in the aortic valve. Of 3 patients with preexisting heart disease, 2 had involvement of the aortic valve and 1 of the mitral valve. Six patients were cured, 2 or possible 3 by treatment with ampicillin, 2 with cephalothin, and 1 with co-trimoxazole. In 2 patients intractable heart failure necessitated the insertion of prosthetic valves, and 1 patient died. Thus, cases of septicemia and endocarditis due to H. parainfluenzae have been observed only in recent years and they appear to be serious infections.