Leishmania tropica is a parasite that infects human macrophages. Sand flies of the genus Phlebotomus act as the vector in the Old World, and of the genus Lutzomyia in the New World.
1. Promastigote forms in the Phlebotomus fly
2. Fly bites a human and injects parasite into the skin
3. The parasite invades the recticuloendothelial cells
4. The amastigote reporduces asexually in the human cells and invades other lymphoid tissue (diagnostic stage)
5. When another Phlebotomus fly bites the human it ingests the amastigote parasite
6. The amastigote transforms into the promastigote and reproduces in the midgut
7. The parasite then migrates to the proboscis where it is now ready to infect another human
This parasite infects the macrophages of human cells. as the genes of the parasite take over the macrophage it transforms it into a cell that destroys and feeds on other macrophages and cells.
This self limiting disease is characterized by oriental sores and is otherwise known as cutaneous leishmania.