Diagram showing the sand fly and human stages of leishmaniasis. Credit: NIAID.
1) Sand fly injects promastigotes into the skin during a blood meal. *infective stage
2) Promastigotes are phagocytized by neutrophils that are rapidly recruited to the bite site.
3) Infected neutrophils release the parasites which are then consumed by macrophages.
4) Promastigotes transform into amastigotes inside macrophages. *diagnostic stage
5) Amastigotes multiply in cells (including macrophages) of various tissues. *diagnostic stage
Sand Fly Stages
6) Sand fly ingests infected macrophages when it takes a blood meal.
7) Ingestion of parasitized cell.
8) Amastigotes transform into promastigotes in midgut.
9) Promastigotes divide and migrate to the anterior midgut and foregut.
10) Sand fly injects promastigotes into the skin during a blood meal. *infective stage
Last Updated September 25, 2008