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Hemoflagellates

Trypanosoma brucei gambiense

Distribution

It is endemic in scattered foci in West and Central Africa. The principal vectors are
Glossina palpalis and Glossina tachynoides (riverine tsetse flies).

Habitat

Trypanosomes live in human and other vertebrate hosts. From the blood, they invade
regional lymph nodes and finally CNS.

Morphology

1. In vertebrate host
Trypomastigote form, which is highly pleomorphic (long slender form, stumpy
short broad form and an intermediate form), is about 15–40 μm long and 1.5–3.5 μm
broad (Fig. 5.1). In fresh blood films, trypomastigotes are extracellular, colourless,
spindle shaped bodies moving rapidly and spinning around the red cells.
2. In vector (tsetse fly)
Occurs in 2 forms:
(a) Epimastigotes
(b) Metacyclic trypomastigotes

Life Cycle (Fig. 5.2)

Trypanosoma brucei gambiense completes its life cycle in 2 hosts. Vertebrate hosts
are humans. Game and other domestic animals can also be infected. (1) Tsetse fly (the

© Springer International Publishing AG 2017 25
R. Mahmud et al., Medical Parasitology,
https://doi.org/10.1007/978-3-319-68795-7_5