Current understandings on the immunology of leishmaniasis and recent developments in prevention and treatment

Leishmaniasis is a major tropical disease with a wide clinical spectrum of cutaneous, mucocutaneous and visceral involvement. Presentation is often varied and diagnosis can be challenging. The outcome of infection is determined by the parasite species and the host’s immunological response. The CD4+ T helper cell is critical with animal models demonstrating that cure is associated with strong IFN-γ, interleukin (IL)-2 and IL-12 responses in the absence of classical Th2 cytokines or IL-10. Prevention has focussed on vector control, control of animal reservoirs and efforts to develop a protective vaccine. Treatment options historically have relied on antimonials though agents with better tolerability and efficacy have been developed including amphotericin and the oral agent miltefosine. Drug resistance, human immunodeficiency virus and changes in vector epidemiology threaten recent advances. Renewed impetus led by the WHO is required to co-ordinate future international effort to develop new drugs and ultimately a vaccine.