Abstract
Background
Cutaneous leishmaniasis (CL) in Ethiopia has typically been linked to high-altitude regions but has recently emerged at an unusually low altitude of 500 meters in the Somali Region, raising public health concerns. Cutaneous leishmaniasis has not been previously identified in the region. There is a conflict in the starting area and only militias have been infected with very serious lesions.
Methodology/Principal findings
Routine clinical and socio-demographic information was extracted from the patient chart using a case report form. Additionally, clinical and laboratory data were obtained from 30 patients suspected for CL. Skin scraping and fine needle aspirates were collected from the raised edges, nodular and centre of the lesions followed by DNA extraction using the DNeasy Blood and Tissue kit. There were a total of 1050 CL patients recruited, all of them were male militia members, immunologically naïve and displaced into a conflict area with a likely sylvatic transmission cycle. We identified Leishmania tropica as the causative species, challenging the previous assumption that L. aethiopica was the primary agent of CL in Ethiopia. Notably, over 77% of patients had more than 10 lesions, a presentation atypical for L. tropica elsewhere. Phlebotomus orientalis and P. sergenti, vectors for visceral leishmaniasis and CL in North Africa respectively, were found in the outbreak area.
Conclusions/Significance
Further research is needed to explore the eco-epidemiology of the outbreak and patient’s treatment responses. Insights will help develop management strategies to control this newly emerging form of CL, prevent its spread to other regions and hybridization with Leishmania strains causing VL endemic in the area.
Author summary
Cutaneous leishmaniasis (CL) is a significant public health problem in Ethiopia and is spread by female sandflies. The causative agent is Leishmania aethiopica, and the reservoir hosts are rock and tree hyraxes. After being bitten by a sand fly, distinct skin lesions typically develop within 6 weeks of infection. The ulcers can persist for varying durations and heal slowly and causing ugly scarring. This disease is mainly found in the highland areas of the country. However, there have been recent changes in the transmission patterns of CL in Ethiopia, with the disease now being identified in lowland areas and involving different hosts and vectors. In recent reports, there have been findings of hybrid parasites resulting from L. donovani/L. aethiopica and L. donovani/L. tropica species. Additionally, cases of CL caused by L. donovani have been documented. A high number of cases, predominantly among male militia members, were reported following the recent outbreak of CL in the Somali region of Ethiopia. Our study has identified the infecting Leishmania species as L. tropica, causing atypical skin lesions. This study sheds light on the emergence of L. tropica as a new Leishmania species, responsible for causing skin lesions in the lowlands of Ethiopia.
Cutaneous leishmaniasis (CL) in Ethiopia has typically been linked to high-altitude regions but has recently emerged at an unusually low altitude of 500 meters in the Somali Region, raising public health concerns. Cutaneous leishmaniasis has not been previously identified in the region. There is a conflict in the starting area and only militias have been infected with very serious lesions.
Methodology/Principal findings
Routine clinical and socio-demographic information was extracted from the patient chart using a case report form. Additionally, clinical and laboratory data were obtained from 30 patients suspected for CL. Skin scraping and fine needle aspirates were collected from the raised edges, nodular and centre of the lesions followed by DNA extraction using the DNeasy Blood and Tissue kit. There were a total of 1050 CL patients recruited, all of them were male militia members, immunologically naïve and displaced into a conflict area with a likely sylvatic transmission cycle. We identified Leishmania tropica as the causative species, challenging the previous assumption that L. aethiopica was the primary agent of CL in Ethiopia. Notably, over 77% of patients had more than 10 lesions, a presentation atypical for L. tropica elsewhere. Phlebotomus orientalis and P. sergenti, vectors for visceral leishmaniasis and CL in North Africa respectively, were found in the outbreak area.
Conclusions/Significance
Further research is needed to explore the eco-epidemiology of the outbreak and patient’s treatment responses. Insights will help develop management strategies to control this newly emerging form of CL, prevent its spread to other regions and hybridization with Leishmania strains causing VL endemic in the area.
Author summary
Cutaneous leishmaniasis (CL) is a significant public health problem in Ethiopia and is spread by female sandflies. The causative agent is Leishmania aethiopica, and the reservoir hosts are rock and tree hyraxes. After being bitten by a sand fly, distinct skin lesions typically develop within 6 weeks of infection. The ulcers can persist for varying durations and heal slowly and causing ugly scarring. This disease is mainly found in the highland areas of the country. However, there have been recent changes in the transmission patterns of CL in Ethiopia, with the disease now being identified in lowland areas and involving different hosts and vectors. In recent reports, there have been findings of hybrid parasites resulting from L. donovani/L. aethiopica and L. donovani/L. tropica species. Additionally, cases of CL caused by L. donovani have been documented. A high number of cases, predominantly among male militia members, were reported following the recent outbreak of CL in the Somali region of Ethiopia. Our study has identified the infecting Leishmania species as L. tropica, causing atypical skin lesions. This study sheds light on the emergence of L. tropica as a new Leishmania species, responsible for causing skin lesions in the lowlands of Ethiopia.
| Original language | English |
|---|---|
| Article number | e0013246 |
| Journal | PLoS Neglected Tropical Diseases |
| Volume | 19 |
| Issue number | 7 |
| Number of pages | 15 |
| ISSN | 1935-2727 |
| DOIs | |
| Publication status | Published - Jul-2025 |