Leishmania parasites are the causative agents of diseases ranging from self-healing cutaneous lesions known as Oriental Sore to the lethal visceral leishmaniasis known as Kala-Azar. According to WHO figures, more than 12 million humans are currently infected, with 2 million new infections per year. Leishmaniasis exists in 88 countries on four continents and is a major, compounding complication in HIV infections.
The parasites are unicellular microorganisms that are transmitted to mammals, including humans, by blood-feeding sandflies. They infect and destroy the macrophages of the mammalian immune systems, thereby causing varying forms of immune pathologies.