Prevalence of Leishmania infection in refugee camps: A serological and molecular study in Gambella and Benishangul-Gumuz, Ethiopia

Background

Leishmaniasis, transmitted by sandflies, causes a severe health threat in East African refugee camps. High mobility, poor conditions and limited healthcare access heighten the risk of visceral leishmaniasis (VL) among refugees. Though, data on infection prevalence is remains limited. This study aims to determine the prevalence of Leishmania infection in refugee camps in Benishangul Gumuz and Gambella regions to improve VL detection and guide effective control strategies in humanitarian settings.

Methods

A cross-sectional study was conducted from May to August 2023 in four refugee camps to determine Leishmania infection using DAT and rtPCR on blood samples. Sociodemographic and clinical data were collected using structured questionnaires. Ethical approval was granted, and informed consent was obtained. Data were analyzed using SPSS v23, with associations assessed using logistic regression and Chi-square tests at a 0.05 significance level. Continuous variables summarized by median and interquartile range (IQR).

Results

The study included 1,223 participants (440 from Tsore camp and 220 from Sherkole in Benishangul Gumuz Region; 288 from Kule camp and 275 from Terkidi in Gambella Region), most of whom were from South Sudan (66.7%) and the majority were females (56.5%). 17.8% of the participants reported fever, with no spleen or liver enlargement and 0.2% lymph node swelling. Real-time PCR positivity was significantly higher in Tsore (14.6%, χ² = 21.4, p < 0.001), no significant difference in DAT positivity was observed across refugee camps (χ² = 6.6, p = 0.084). Leishmania DAT positivity rates were 6.0%, 4.6% and 4.7% in those with fever, chills and headache, respectively. Leishmania kDNA based rtPCR positivity rate were 11.7%, 8.8%, 7.3% and 6.2% in those with fever, chills, headache and weakness, respectively. Participants from Benishangul Gumuz region [AOR: 3.67 (95%CI: 1.57-8.59); p = 0.003]; South Sudanese [AOR: 2.87 (95%CI: 1.26-6.50); p = 0.012 and those with fever [AOR: 2.08 (95%CI: 1.01-4.28); p = 0.047] had a higher odds of DAT positivity. On the other hand, lower rtPCR positivity rates were seen in the Sherkole refugee camp compared to Tsore camps in Benishangul Gumuz region [AOR: 0.19 (95%CI: 0.08-0.45); p < 0.0001].

Conclusion

Leishmania infection was prevalent in refugee camps in Gambella and Benishangul Gumuz regions. Asymptomatic cases and low parasite loads were common, highlighting the need for active case detection, intervention including treatment and vector control to manage VL transmission effectively.

Author summary

Leishmaniasis poses a significant health threat in East African refugee camps, particularly among populations with high mobility, poor living conditions, and limited healthcare access. This cross-sectional study, conducted from May to August 2023, aimed to assess the prevalence of Leishmania infection in four refugee camps in the Benishangul Gumuz and Gambella regions. Using direct agglutination tests (DAT) and RT-PCR on blood samples from 1,223 participants, the study revealed a Leishmania infection prevalence of 4.0% by DAT and 10.3% by RT-PCR. Notably, RT-PCR positivity was significantly higher in Tsore camp (14.6%) compared to Sherkole camp (3.2%), where residents were 81% less likely to be tested positive. Fever, chills, and headache were common symptoms reported by the participants in varying proportions. Sociodemographic factors, such as being from the Benishangul Gumuz region or South Sudan, increased the odds of DAT positivity. These findings underscore the need for active case detection, intervention including treatment tailored interventions, including active case detection and vector control to manage visceral leishmaniasis (VL) in these vulnerable populations effectively.