• Recognizing the burden

    There are 3 main forms of leishmaniases:

    – visceral, also known as kala-azar (which is the most serious form of the disease),

    - cutaneous (the most common),

    - and mucocutaneous.

  • Estimating the impact

    Cutaneous leishmaniasis (CL) is the most common form of leishmaniasis and causes skin lesions, mainly ulcers, on exposed parts of the body, leaving life-long scars and serious disability or stigma. About 95% of CL cases occur in the Americas, the Mediterranean basin, the Middle East and Central Asia. In 2020 over 85% of new CL cases occurred in 10 countries: Afghanistan, Algeria, Brazil, Colombia, Iraq, Libya, Pakistan, Peru, the Syrian Arab Republic and Tunisia. It is estimated that between 600 000 to 1 million new cases occur worldwide annually.

    (The Lancet. 10 March 2022. doi: 10.1016/S0140-6736(21)02796-3.)

  • Prevention and control

    Early diagnosis and effective prompt treatment reduces the prevalence of the disease and prevents disabilities and death. It helps to reduce transmission and to monitor the spread and burden of disease.

    In visceral leishmaniasis, diagnosis is made by combining clinical signs with parasitological, or serological tests (such as rapid diagnostic tests). In cutaneous and mucocutaneous leishmaniasis rapide diagnostic tests are available and clinical manifestation with parasitological tests confirms the diagnosis.

    (WHO, 2022)

  • Global burden of cutaneous leishmaniasis: a cross-sectional analysis from the Global Burden of Disease Study 2013

    In 201, Andean Latin America, North Africa and Middle East, western sub-Saharan Africa, and south Asia had the highest DALYs from cutaneous leishmaniasis. Among males, Palestine had the highest incidence rates (616·2 cases per 100 000 people) followed by Afghanistan (566·4), Syria (357·1), and Nicaragua (354·8). Among females, Afghanistan had the highest incidence rates (623·9) followed by Syria (406·3), Palestine (222·1), and Nicaragua (180·8). Similar proportions of males and females had cutaneous leishmaniasis in most countries with a high incidence.

    (Karimkhani, Chante et al.The Lancet Infectious Diseases, Volume 16, Issue 5, 584 - 591)

  • Global leishmaniasis surveillance: 2021

    In 2021, 221 953 new CL cases (221 614 autochthonous and 339 imported) and 11 743 new VL cases (11 689 autochthonous and 54 imported) were reported to WHO (Table 1). The results are calculated for new autochthonous cases, excluding those that were imported and relapse cases. Eastern Mediterranean Region and Algeria constitute an eco-epidemiological “hotspot”,
    as together they reported 82% (181 971) of all new CL cases. Nine countries (Afghanistan, Algeria, Brazil, Colombia, Islamic Republic of Iran, Iraq, Pakistan, Peru and the Syrian Arab Republic) each reported >5000 CL cases, for a total of 195 283, representing >85% of cases globally.

    WHO 2021. WER No. 45, 2022, 97, 575–590

  • Target Product Profile for a point-of-care diagnostic test for dermal leishmaniases

    A rapid, simple test to be used in the point-of-care diagnosis of the different forms of CL, including localized CL (LCL), mucocutaneous leishmaniasis (MCL), diffuse cutaneous leishmaniasis (DCL), and cutaneous leishmaniasis recidivans (CLR). Also applicable to PKDL. To be applied ideally in decentralized health care facilities with no laboratory infrastructure.

    Read more.

FAQs

What is leishmaniasis?

Leishmaniasis is caused by a protozoa parasite from over 20 Leishmania species. Over 90 sandfly species are known to transmit Leishmania parasites.

What are the different types of leishmaniasis?

There are 3 main forms of the disease:

Visceral leishmaniasis (VL), also known as kala-azar is fatal if left untreated in over 95% of cases. It is characterized by irregular bouts of fever, weight loss, enlargement of the spleen and liver, and anaemia. Most cases occur in Brazil, East Africa and in India. An estimated 50 000 to 90 000 new cases of VL occur worldwide annually, with only between 25 to 45% reported to WHO. It remains one of the top parasitic diseases with outbreak and mortality potential. In 2020, more than 90% of new cases reported to WHO occurred in 10 countries: Brazil, China, Ethiopia, Eritrea, India, Kenya, Somalia, South Sudan, Sudan and Yemen. 

Cutaneous leishmaniasis (CL) is the most common form of leishmaniasis and causes skin lesions, mainly ulcers, on exposed parts of the body, leaving life-long scars and serious disability or stigma. About 95% of CL cases occur in the Americas, the Mediterranean basin, the Middle East and Central Asia. In 2020 over 85% of new CL cases occurred in 10 countries: Afghanistan, Algeria, Brazil, Colombia, Iraq, Libya, Pakistan, Peru, the Syrian Arab Republic and Tunisia. It is estimated that between 600 000 to 1 million new cases occur worldwide annually.

Mucocutaneous leishmaniasis leads to partial or total destruction of mucous membranes of the nose, mouth and throat. Over 90% of mucocutaneous leishmaniasis cases occur in Bolivia (the Plurinational State of), Brazil, Ethiopia and Peru.

What are the risk factors for leishmaniasis?

Poverty increases the risk for leishmaniasis. Poor housing and domestic sanitary conditions (such as a lack of waste management or open sewerage) may increase sandfly breeding and resting sites, as well as their access to humans. Sandflies are attracted to crowded housing as these provide a good source of blood-meals. Human behaviour, such as sleeping outside or on the ground, may increase risk.

Malnutrition: Diets lacking protein-energy, iron, vitamin A and zinc increase the risk that an infection will progress to a full-blown disease.

Population mobility: Epidemics of both cutaneous and visceral leishmaniasis are often associated with migration and the movement of non-immune people into areas with existing transmission cycles. Occupational exposure as well as widespread deforestation remain important factors.

Environmental changes: The incidence of leishmaniasis can be affected by changes in urbanization, and the human incursion into forested areas.

Climate change: Leishmaniasis is climate-sensitive as it affects the epidemiology in several ways: changes in temperature, rainfall and humidity can have strong effects on vectors and reservoir hosts by altering their distribution and influencing their survival and population sizes;small fluctuations in temperature can have a profound effect on the developmental cycle of Leishmania promastigotes in sandflies, allowing transmission of the parasite in areas not previously endemic for the disease;drought, famine and flood can lead to massive displacement and migration of people to areas with transmission of Leishmania, and poor nutrition could compromise their immunity.

How is leishmaniasis diagnosed?

In visceral leishmaniasis, diagnosis is made by combining clinical signs with parasitological, or serological tests (such as rapid diagnostic tests). In cutaneous and mucocutaneous leishmaniasis serological tests have some value and clinical manifestation with parasitological tests confirms the diagnosis.

Disclaimer: The Learn Resources section is a compilation of information on a given topic that is drawn from credible sources; however, this does not claim to be an exhaustive document on the subject. It is not intended to be prescriptive, nor does it represent the opinion of FIND or its partners.