Situation and trends
The leishmaniases are a group of diseases caused by the protozoa parasite Leishmania. Over 20 Leishmania species known to be infective to humans are transmitted by the bite of infected female phlebotomine sandflies. There are three main types of leishmaniasis: i) visceral, often known as kala-azar and the most serious form of the disease (VL); ii) cutaneous, the most common (CL); and iii) mucocutaneous.
The disease mainly affects poor people in Africa, Asia and Latin America, and is associated with malnutrition, population displacement, poor housing, weak immune system and lack of resources. Out of 200 countries and territories reporting to WHO, 97 countries and territories are endemic for leishmaniasis in 2018. This includes 68 countries that are endemic for both VL and CL, 8 countries that are endemic for VL only and 21 countries that are endemic for CL only.
Since 2013, the WHO Global Leishmaniasis programme has been reporting separately the number of new autochthonous cases, to monitor the trends in incidence, and the number of imported cases.
As of December 2019, 52 VL-endemic countries (68%) and 59 CL-endemic countries (66%) reported data to the WHO Global Leishmaniasis programme for 2018. Over 90% of global VL cases were reported from seven countries: Brazil, Ethiopia, India, Kenya, Somalia, South Sudan and Sudan. In 2018, 11 countries reported more than 5000 CL cases: Afghanistan, Algeria, Bolivia, Brazil, Colombia, the Islamic Republic of Iran, Iraq, Pakistan, Peru, the Syrian Arab Republic and Tunisia, which together account for 88% of global reported CL incidence. In 2018, there were 1039 imported cases of cutaneous leishmaniasis reported globally (with no data available from Turkey, which reported alone 1089 imported CL cases in 2016). Comparatively, the number of imported cases of visceral leishmaniasis was lower, with a total of 140 imported cases reported globally in 2018. Uganda reported approximately 50% of these cases.
As of December 2019, 50 VL-endemic countries (66%) and 52 CL-endemic countries (60%) have reported 2017 data to the WHO Global Leishmaniasis programme.