Cutaneous Leishmaniasis in Tigray, Ethiopia: Clinical patterns, environmental drivers and public health implications

Cutaneous leishmaniasis (CL) is a vector-borne skin disease caused by the bite of female sandflies infected with the Leishmania parasite and is widely distributed in the highlands of Tigray, Northern Ethiopia. However, despite its widespread distribution, little is known about the actual epidemiology of the disease in Tigray and Ethiopia as a whole. Therefore, this study aimed to document the epidemiology, risk factors and public health implications of CL in Tigray, Ethiopia.

Between March and May 2022, a cross-sectional household survey was conducted in seven districts of Tigray, Northern Ethiopia, using multistage sampling technique. Participants were clinically examined for scars and/or active lesions and samples taken from active lesions were investigated for parasite amastigotes by microscopy. Data on socio-demographic characteristics and environmental determinants were documented using semi-structured questionnaires. Bivariate and multivariate logistic regressions were used to identify risk factors associated with CL infections.

A total of 3,817 individuals (48.2% males and 51.8% females) residing in 927 households were screened and included in the study. A total of 484 individuals showed clinical evidence of CL infection (13.7% of all males, 11.5% of all females). The overall prevalence was found to be 12.7% (4.5% active lesions, 8.2% scars). Active cases were predominantly localized cutaneous leishmaniasis (LCL) (85%) but a substantial number of mucocutaneous (MCL) cases (11%) and diffused (DCL) (4%) types were also identified. The highest rates of active lesions (5.2%) were found in children aged 1-14 years. Most lesions (69%) occurred on the face, and 51.4% of cases had ≥ 2 lesions. Of the study sites screened, Emba Alaje district had the highest prevalence (15.7%). Cases clustered in highland zones (70.2% at 2,300-3,200 m altitude; 93% at 2,000-3,000 m). Significant host risk factors included age, outdoor sleeping and poor housing (cracked walls). Moreover, proximity to hyraxes, bats, caves, or animal burrows were identified among the significant environmental risk factors (p < 0.05).

Cutaneous leishmaniasis is an underprioritized yet serious public health challenge in Tigray, driven by environmental and behavioral factors. Several forms of the disease (LCL, MCL and DCL) are prevalent in the region, with children and young adults being the most affected. Advocacy for regional recognition of CL, integration of CL control into existing NTD programmes is recommended. Targeted interventions for high-risk groups, enhanced surveillance and mapping, vector and reservoir control measures, community awareness and healthcare capacity and a One Health approach are highly recommended-for sustainable control of CL in Tigray, Ethiopia.