Pancarditis with valvulitis in endomyocardial fibrosis (=emf) and in human African trypanosomiasis (= hat). A comparative histological study of four Ugandan cases.

The study compares the histotopographical lesions of two cases of endomyocardial fibrosis with those of two hearts in sleeping sickness, all of them from Uganda. There was considerable overlapping of the fibrosed zones in endomyocardial fibrosis and the corresponding sites occupied by the chronic inflammatory process in trypanosomiasis. There was a tendency towards fibrosis in the hearts of trypanosomiasis while, in endomyocardial fibrosis, there were mild focal chronic cellular infiltrations. This overlapping and to some extent similarities would suggest that the two conditions may only differ in evolution in time and intensity and that they may be the result of the same inflammatory process. Stipulating a cardiac tropism for African trypanosomes, it is suggested that some African cases of endomyocardial fibrosis may be merely burnt-out lesions of trypanosomal pancarditis. Previous descriptions of carditis in human African and American trypanosomiasis are briefly reviewed, and the present findings are discussed in view of a possible trypanosomal aetiology in some African cardiomyopathies.