SYNOPSIS Haemophilus aphrophilus was isolated from the blood of a 31-year-old man with subacute bacterial endocarditis. Subsequently the patient died with acute tubular necrosis of the kidney, probably secondary to cardiac failure. The characteristics of the species are described and pathogenicity to mice is reported for the first time.Amongst the many infections caused by species of haemophilus, only rarely has endocarditis been reported. The incidence of Haemophilus in subacute bacterial endocarditis lies between 0 5 and 1 % (Keith and Lyon, 1963), and the species most often involved are H. influenzae and H. parainfluenzae. Endocarditis due to a third species, H. aphrophilus, was first described in London (Khairat, 1940), and recently interest in this organism has been shown in America although fewer than 30 cases of H. aphrophilus endocarditis have been reported. Since the original account, before the advent of antibiotics, no infection due to H. aphrophilus had been reported in Britain until microorganisms resembling this species were described in reports (Speller, Prout, and Saunders, 1968;Vickerstaff, Pease, and Rogers, 1968) which suggested the possibility that the presence of such organisms may remain undetected unless appropriate methods are used. Therefore we considered it of value to describe the features of H. aphrophilus isolated from a recent fatal case of endocarditis.
CASE REPORTA 31-year-old man was admitted to hospital with a history of haematuria for two weeks and ankle swelling for two months. One year previously he had experienced a bout of fever, rigors, and flitting joint pains, and was thought to have had rheumatic fever, after which he had continued to feel unwell. On admission to hospital he had gross congestive cardiac failure, with haematuria and a petechial rash on the hands, torso, and legs. The teeth were carious and the gums septic. The haemoglobin was 4-4/100 ml and the white cell count 16,000/cmm with 91% neutrophils. The blood urea level was 52 mg/100 ml.A diagnosis of subacute bacterial endocarditis with mitral incompetence was made, and two blood cultures were taken. Both yielded Haemophilus aphrophilus. Treatment was begun with ampicillin together with
