Leishmaniasis.

Leishmaniasis remains an important neglected tropical infection that affects children more than adults. Geographical variation exists in the distribution of the various Leishmania species. Although the majority of the disease burden is found in poor countries, leishmaniasis is also endemic in several countries within Southern Europe. Transmission is mediated by the sandfly and may follow an anthroponotic or zoonotic cycle that also varies by region. The expression of leishmaniasis depends on a complex interaction between the type of infecting species and the host immune response. Infection may be asymptomatic or may manifest as cutaneous disease that is pleiomorphic in presentation, muco-cutaneous disease or the visceral form that may be lethal if untreated. Molecular techniques aid diagnosis especially in cases where amastigotes are not visualised. The efficacy of treatment varies with the type of infecting species and resistance patterns. Preventive measures aimed at avoiding sandfly bites are effective in reducing acquisition of leishmaniasis and should be promoted for travellers visiting endemic regions. The persistent lack of a vaccine against human leishmaniasis is a result of the poor investment in this neglected parasitosis.