Leishmaniasis is a vector-borne disease with a variety of parasite species, reservoirs, and vectors involved in the route of transmission.
Leishmaniasis is caused by the protozoa Leishmania, which are spread by a variety of sand fly species. There are three different clinical manifestations of Leishmaniasis: cutaneous (skin), mucosal (mucus-membrane) and visceral (the most severe form, which affects internal organs). The presence of Leishmaniasis is directly linked to poverty, but social, environmental and climatologic factors directly influence the disease’s epidemiology. Leishmaniasis is classified as a Neglected Tropical Disease (NTD) and endemic in 98 countries and territories, with more than 350 million people at risk.
Leishmaniasis is caused by protozoan parasites belonging to the genus Leishmania. The parasites are transmitted by the bite of a tiny – only 2 to 3 mm long – insect vector called the phlebotomine sandfly. There are some 500 known phlebotomine species, but only about 30 have been found to transmit leishmaniasis. Only the female sandfly transmits the parasites.
Leishmaniasis threatens about 350 million men, women and children in 88 countries around the world. As many as 12 million people are believed to be currently infected, with about 1 to 2 million estimated new cases occurring every year.
The disease can have a wide range of clinical symptoms, which may be cutaneous, mucocutaneous or visceral. Cutaneous leishmaniasis is the most common form. Visceral leishmaniasis is the most severe form, in which vital organs of the body are affected.
The burden of the disease in Africa is still under assessment. Affected countries in Africa are mainly Ethiopia and neighbouring countries in East Africa (Kenya, South Sudan, Uganda) which are affected by the two forms of the disease. Central Africa countries also have all of the forms with predominance of the cutaneous form while in West African countries only the cutaneous form of the disease is found mainly in the Sahel strip countries (Burkina Faso, Mali, Niger and Senegal).