Existing and newly emerging human cutaneous Leishmania isolates in Ethiopia: a systematic review

Background: Cutaneous leishmaniasis (CL) is a significant public health issue, caused by various Leishmania species. In Ethiopia, L. aethiopica is typically recognized as the primary causative agent of CL. However, emerging Leishmania species from regions with limited foci indicate the possibility of additional isolates. Identification of Leishmania species causing CL is essential for understanding epidemiology, predicting outcomes, and managing the disease effectively. Thus, this review intends to identify and map the distribution of existing and newly emerging CL-causing agents in Ethiopia.

Methods: A comprehensive search of electronic databases was conducted to identify relevant studies. The search included electronic databases such as PubMed, Science Direct, Cochrane Library, Hinari-Reserch4Life, Google Scholar, and other search sources for English articles published between 2000 and 2024. The quality of the included studies was assessed using the JBI quality appraisal tool. This study adhered to the PRISMA guidelines. Data were extracted using a Microsoft Excel 2010 and data obtained were then reported using tables and figures. The evidence was summarized using a narrative synthesis.

Results: Out of the studies reviewed, seven met the inclusion criteria, with the majority being cross-sectional studies. Our findings confirm L. aethiopica as the primary cause of CL in Ethiopia, accounting for 97.2% of cases, in line with its established prevalence across nearly all endemic regions of the country. A key finding was the identification of L. donovani as a newly recognized cause of CL, confirmed through ITS-1 HRM PCR and HSP70 amplicon sequencing, accounting for 2.8% of cases in the reviewed studies, particularly in the northern endemic foci. The reviewed studies mainly used the ITS-1 region as the primary molecular marker for identifying Leishmania species associated with CL, while the HSP70 marker was also employed to ensure more accurate species identification.

Conclusion: Given that L. aethiopica is the main species associated with CL in Ethiopia. A noteworthy finding is the identification of L. donovani as a newly isolated causative agent of CL in the country. These findings are essential for directing public health campaigns and supporting scientists in developing better CL diagnosis and treatment alternatives in Ethiopia.