Leishmania spp. cause a spectrum of disease including visceral, cutaneous, and mucocutaneous forms. What is the vector?

• A. Visceral, cutaneous, mucocutaneous; sandfly
• B. Mosquito; malaria-like symptoms
• C. Visceral leishmaniasis only; sandfly
• D. Cutaneous leishmaniasis; tsetse fly

Answer: (A)

Leishmania infections are transmitted by female phlebotomine sandflies. The disease can present as visceral, cutaneous, or mucocutaneous forms depending on the Leishmania species, but the common vector across these forms is the sandfly. In humans, the parasite lives inside macrophages as amastigotes; in the sandfly, it develops into promastigotes in the midgut and is transmitted to the human host during a subsequent bite. Mosquitoes transmit malaria and other diseases, while tsetse flies transmit African sleeping sickness, so neither is the vector for Leishmania.