Geographic Distribution of Leishmania Species
Leishmania species distribution varies dramatically by geographic region, with distinct patterns in the Old World (Eastern Hemisphere) versus New World (Americas), and specific species predominating in defined endemic zones.
Old World (Eastern Hemisphere)
Mediterranean Basin & Southern Europe
- L. infantum is the predominant species throughout the Mediterranean area, causing both visceral leishmaniasis and cutaneous leishmaniasis in Central-Western Europe, including Italy 1
- L. tropica has very limited distribution, restricted to Middle East, Tunisia, and Greece, causing urban (anthroponotic) cutaneous leishmaniasis 1
- L. major is widespread throughout North Africa and Middle East, causing rural (zoonotic) cutaneous leishmaniasis 1
Middle East & Iran Region
- L. tropica and L. major are the main causative agents of anthroponotic and zoonotic cutaneous leishmaniasis respectively 2
- L. infantum and L. donovani occasionally cause cutaneous disease in addition to visceral leishmaniasis 2
- Notable expansion of L. tropica into new urban and rural foci, with documented visceralization cases 2
East Africa (Ethiopia)
- L. aethiopica is the most commonly reported cause of cutaneous leishmaniasis (93.1% of cases) 3
- L. tropica accounts for approximately 6.9% of cases 3
- L. donovani causes visceral leishmaniasis and has been identified in putative hybrids with L. aethiopica (13.4% of isolates) 3
New World (Americas)
Geographic Risk Stratification for Mucosal Leishmaniasis
Highest risk areas ("mucosal belt"): South of the Amazon basin in Bolivia, Peru, and Brazil 4
Moderate risk areas: South of Nicaragua to the Amazon basin 4
Low risk areas: New World regions north of Costa Rica 4
South America
Peru
- L. (V.) braziliensis predominates (79% of isolates), associated with cutaneous, mucosal, and mixed disease 5
- L. (V.) peruviana (10% of cases), primarily causing cutaneous lesions 5
- L. (V.) guyanensis (7% of cases), associated with cutaneous disease 5
- L. (V.) lainsoni (2% of cases), causing cutaneous lesions 5
- L. (L.) amazonensis (1.7% of cases), associated with cutaneous, mucosal, and diffuse cutaneous leishmaniasis 5
Distribution spans at least 15 different Departments, primarily in low and high jungle regions 5.
Venezuela (Central-Western)
- L. (L.) amazonensis is the dominant species (77.63% of cases), widely dispersed throughout Lara state 6
- L. (L.) infantum has emerged as an etiologic agent of cutaneous leishmaniasis (14.47% of cases) - this is unprecedented documentation for this region 6
- L. (V.) panamensis (5.26% of cases) 6
- L. (V.) braziliensis (2.63% of cases) 6
Central America & Mexico
- L. mexicana causes cutaneous leishmaniasis with spontaneous healing in 3-9 months, but rarely associated with diffuse cutaneous leishmaniasis 4
- L. (V.) panamensis present in Panama and extending into South America 4
Species-Specific Clinical Implications
High Mucosal Risk Species
L. (V.) braziliensis carries the highest risk for mucosal leishmaniasis, particularly from Costa Rica southward 4. L. (V.) guyanensis and L. (V.) panamensis also pose increased mucosal risk 4.
Healing Timeframes by Species
- L. major: 2-6 months 4
- L. mexicana: 3-9 months 4
- L. tropica, L. (V.) braziliensis, L. (V.) panamensis: 6-15 months 4
Diffuse Cutaneous Leishmaniasis Species
Critical Clinical Pitfalls
Species identification is essential for risk stratification. When the specific species is unknown, use geographic acquisition as a proxy: infections acquired from Costa Rica southward should be treated as high mucosal risk, even if lesions appear benign or are healing 4. Civil conflict, population displacement, and climate change are actively reshaping Leishmania distribution patterns, particularly in Syria, Iraq, and Turkey 2.