In Mexico and Central America, this parasite is the primary cause of cutaneous leishmaniasis.

[1] Infected sandflies carry L. mexicana in its promastigote form, transmitting it from their salivary glands through their proboscis into the bloodstream of the host.

When macrophages phagocytize the parasite, it transitions into its amastigote form, rapidly dividing to break the host cell open and infect other mononuclear phagocytic cells.

When uninfected sandflies ingest the blood of an infected animal, they acquire L. mexicana, which returns to the promastigote form to efficiently survive in the insect's midgut.

Treatment of Leishmaniasis caused by L. mexicana consists of pentavalent antimonials as Pentostam or Glucantime injected direct into the ulcer or Intramuscular.