Leishmaniasis is caused by which of the following?

Leishmaniasis is caused by parasites of the genus Leishmania, which are transmitted to humans through the bite of infected sandflies. Sandflies are small, blood-feeding insects that thrive in warm and humid environments, often found in tropical and subtropical regions. The bites from these sandflies facilitate the transmission of the parasites, leading to leishmaniasis, which can manifest in various clinical forms, ranging from cutaneous to visceral leishmaniasis.

Understanding the role of the sandfly in the life cycle of Leishmania is crucial for recognizing the transmission dynamics and epidemiology of leishmaniasis. The prevention of leishmaniasis often focuses on controlling sandfly populations and protecting individuals from bites, highlighting the importance of this vector in the disease's spread. Other options such as ticks, mosquitoes, or fleas are not involved in the transmission of leishmaniasis, making the association with sandflies specifically relevant to the disease.