Echinococcosis in Humans and Animals in Algeria: A Systematic Review and Meta-analysis.

Abstract

BACKGROUND: Cystic echinococcosis (CE), caused by Echinococcus granulosus, remains an endemic yet insufficiently documented zoonotic disease in Algeria. This study provides the first nationwide systematic review and meta-analysis summarizing epidemiological data from 2003 to 2024 in humans and animals, as no relevant studies were available prior to 2003. METHODS: A systematic search of nine databases (last updated: February 2025) was conducted following PRISMA 2020 guidelines. Studies were screened and selected based on predefined eligibility criteria, resulting in 26 studies (22 animal studies and 4 human studies). Data extraction was performed independently by two reviewers using a standardized form. Pooled prevalence estimates and 95% confidence intervals (CI) were calculated using a random-effects model. Heterogeneity was assessed using Cochran's Q, τ² and I² statistics. Subgroup analyses were conducted according to host species, region, and study period. Publication bias was evaluated with funnel plots and Egger's test. Human and animal datasets were analyzed separately to ensure comparability. RESULTS: A total of 764,040 animal samples were included, yielding an overall pooled prevalence of 4.69% (35,802 positive cases). The highest pooled prevalence was observed in dogs (16.9%). Among livestock, sheep showed the highest pooled prevalence (5.92%), followed by cattle, camels, and goats. Pooled estimates also indicated infection in horses (6.03%) and wild boars (6.31%), suggesting potential sylvatic transmission. Subgroup analyses revealed significantly higher pooled prevalence in southern regions (10.51%) and a declining temporal trend, from 14.1% in 2003-2009 to 6.09% in 2020-2024. Detection rates varied according to diagnostic methods, with ELISA and post-mortem examination yielding the highest pooled prevalences. All pooled estimates showed extreme heterogeneity (Cochran's Q = 27,254.50; I² = 99.92%), which persisted after Freeman-Tukey transformation. Egger's test indicated significant funnel-plot asymmetry (p = 0.0067), suggesting potential publication bias. Human data were limited to four studies, confirming the persistence of CE mainly in northern regions, but were insufficient to conduct meta-analysis. CONCLUSION: CE remains endemic in Algeria, with pronounced spatial, temporal, and host-related variability. Dogs play a central role in transmission, while the scarcity of human data highlights critical surveillance gaps. A strengthened One Health strategy emphasizing dog deworming, improved slaughterhouse practices, and better diagnostic and reporting systems is urgently needed.