Trypanosoma (schizotrypanum in British Honduras)

ABSTRACT

Previously, the various trypanosome infections detected in the blood of wild-caught mammals and triatomid bugs collected in British Honduras could be referred to as Trypanosoma cruzi-like, because neither pseudocysts nor Leishman Donovan bodies were found in the organs of the infected animals. since June 1966, three strains of trypanosome have been isolated from wild-caught Triatoma dimidiata. All strains were pathogenic to white rats and mice, killing them in 21-25 days after inoculation. In all animals infected with any of these three strains of parasites, pseudocysts and leishmanoid forms were found in heart muscle and in one white rat tissue stages of T.cruzi were found in a smear of the diaphragm. All three strains have been transmitted to clean triatomine bugs, and the infections have been transmitted from the bugs to further clean laboratory animals. A trypanosome can be classified as trypanosoma (Schizotrypanum) cruzi if it fulfills four conditions (a) the trypanosome is morphologically and biometrically identical with T.cruzi; (b) the parasites are pathogenic to healthy laboratory-bred animals; (c) pseudocysts and Leishman Donovan bodies can be detected in the tissues of the infected animals; (d) the parasites are transmissible, either by blood inoculation or through clean triatomine bugs, to healthy animals. The strains of trypanosome isolated in 1966 all fulfill these conditions and it is quite clear that strains of T.cruzi which are highly virulent to experimental animals, exist in British Honduras. It is possible that there is little man-vector contact in the country, and that human T.cruzi infections are purely accidental. Alternatively, the strains of parasite, propagated among while mammalian hosts, may not be very pathogenic to man, thus accounting for the relative absence of patients with acute symptoms of Chagas' disease (AU)