An ultrastructural study on the early development of Leishmania chagasi (Kinetoplastida : Trypanosomatidae) in its vector Lutzomyia longipalpis (Diptera : Psychodidae)

Development of Leishmania chagasi in the blood-meal and the midgut of its vector Lutzomyia longipalpis was studied by light and transmission electron microscopy. It was demonstrated, for the first time, that macrophages are ingested intact and remain so until, at least, 12 hours after the infective blood-meal. The amastigote and promastigote forms appearing between 12-96 hours after infection are described. The previously suggested probability of direct transformation of small unchanged amastigotes into metacyclic promastigotes (Lainson and Shaw, 1988) was not confirmed. All amastigotes disappeared from the midgut before the appearance of any metacyclic promastigote.