| Abstract: | Twenty-five cases of Haemophilus parainfluenzae endocarditis have been reported in the past 10 years, providing a better current perspective of this disease. We have recently diagnosed and treated two patients with H. parainfluenzae endocarditis, and both underwent surgical intervention for complications of their disease. H. parainfluenzae and the other Haemophilus species causing endocarditis often present with a subacute course, often escape early cultural detection and mimic fungal endocarditis in the propensity for large vessel embolization. Multiple emboli and occlusion of major arterial vessels are especially notable features of H. parainfluenzae endocarditis and have occurred in approximately 30 per cent of the cases reported in the past 10 years. In contradistinction to other types of bacterial endocarditis, the most common cause of death in this series has been neurologic complications following embolization.Development of large vegetations appears to be common and may be an intrinsic property of the Haemophilus species, but it is likely that it also reflects the duration of the disease. Delay in recovery of the organism from blood cultures is characteristic of H. parainfluenzae endocarditis and may be due to the strict requirement for V factor exhibited by some strains. Echocardiography has proved useful in suggesting the diagnosis of endocarditis when blood cultures are negative.Optimal antibiotic therapy of H. parainfluenzae endocarditis has not been determined, but the reported clinical experience suggests that combination therapy with ampicillin and an aminoglycoside is the current treatment of choice. Failure to eradicate the organism after a prolonged trial of appropriate antibiotic therapy is not unusual. Indications for surgery in H. parainfluenzae endocarditis may have to be amended to include potential embolization, especially if large vegetations are demonstrated on echocardiography. |
