Infectivity of Trypanosoma rhodesiense to Tsetse Flies fed through Animal Membranes

Abstract

THE trypanosomes belonging to the Trypanosoma brucei group (agents of sleeping sickness and nagana) exist in the blood of the host in three main morphological forms—long thin, intermediate and short stumpy. When these are taken up by the tsetse fly they undergo developmental changes, namely trypanosome, crithridial and metacyclic forms, the last being infective to the vertebrate host. There is controversy about which forms are infective to the fly, the long thin, the short stumpy or both.