Quantitative synthesis and spatial epidemiology of animal cystic echinococcosis in Algeria (2003-2024)

Cystic echinococcosis (CE), caused by Echinococcus granulosus sensus lalo (E. granulosus s.l.), remains a major zoonotic and economic concern in Algeria. This systematic review and meta-analysis aimed to estimate the national prevalence of CE in domestic animals, identify spatial patterns, and evaluate factors contributing to epidemiological variability. Literature searches were performed across nine international and regional databases, and eligible studies published between 2003 and 2024 were screened following PRISMA guidelines. A total of 22 studies were included, yielding 68 independent prevalence estimates from 20 Algerian regions. Study quality was assessed using the Joanna Briggs Institute (JBI) checklist, and statistical analyses including random-effects models, meta-regression, and spatial autocorrelation were conducted in R. Among definitive hosts (dogs), the pooled prevalence was 15.24 % (95 % CI: 4.52-40.61 %; k = 4), with substantial heterogeneity (I² = 94.7 %). For intermediate hosts, analysis of 763,662 animals revealed an overall pooled prevalence of 4.16 % (95 % CI: 2.59-6.63 %), with marked inter-species variability: cattle (12.44 %), camels (7.81 %), sheep (6.31 %), goats (5.21 %), and wild boars (6.32 %). After applying the trim-and-fill method to account for potential missing studies, the adjusted pooled prevalence was 6.42 %. Significant regional disparities were identified, with hyperendemic clusters in Tébessa, M'Sila, and Setif, contrasted with low-risk zones such as Tindouf and Batna. Spatial analysis detected significant positive autocorrelation (Global Moran's I = 0.273; p = 0.033), indicating geographical clustering. Meta-regression revealed sample size and geographic location as key moderators of heterogeneity. This study provides the most comprehensive synthesis of CE prevalence in Algerian livestock to date, highlighting persistent endemicity and spatial hotspots. Findings emphasize the need for strengthened One-Health surveillance, targeted control strategies, and standardized diagnostic protocols to reduce transmission risk and associated economic losses.