Trypanosoma (Megatrypanum) incertumfromPipistrellus pipistrellus: development and transmission by cimicid bugs

Abstract

SUMMARYTrypanosoma (Megatrypanum) incertumPittaluga 1905 was found in 33 out of 206Pipistrellus pipistrelluscaught at various sites in Britain. The trypanosome is described from blood smears. Development took place in laboratory-rearedCimex pipistrelliandCimex lectularius. Epimastigote forms initially multiplied rapidly in the ventriculus and midgut ofCimex. Metacyclic trypanosomes were found in the rectum of both species ofCimexafter 8 days when bugs were maintained at 20 °C and as early as 3 days at 30 °C. Electron microscopy of infected bugs revealed that there was no attachment to epithelial cells of the ventriculus or midgut, but within the rectum epimastigotes were attached by their flagella to the cuticle of the rectum by hemidesmosomes. Transmission was achieved by feeding experimentally infected bugs to bats kept in the laboratory. These bats were negative as judged by xenodiagnosis using laboratory-rearedCimex. Bats which had been caught in the wild demonstrated low-grade or sub-patent parasitaemias (positive in xenodiagnosis) for up to 400 days after the day of capture. Despite an extensive search of impression smears of tissues immediately after trypanosomes first appeared in the blood of experimentally infected bats no multiplicative stages were found.