Chloroquine-resistant Plasmodium vivax malaria in Ethiopia: A systematic review and meta-analysis

Plasmodium vivax accounts for about 40% of malaria cases in Ethiopia, where chloroquine remains the first-line treatment. However, the emergence of chloroquine resistance threatens the effectiveness of treatment. This systematic review synthesizes current evidence on chloroquine-resistant Plasmodium vivax in Ethiopia. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42024564745) and conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Comprehensive searches were performed in PubMed, Medline, EMBASE, Google Scholar, Web of Science, ScienceDirect, and African Journals Online. Data were extracted using Microsoft Excel and analyzed with STATA version 11. Random-effects models were used to estimate pooled prevalence with 95% confidence intervals. Heterogeneity was assessed using the I-squared statistic, and publication bias was evaluated using Egger's test and a funnel plot. Thirteen studies with 2,190 participants reported a pooled prevalence of chloroquine-resistant Plasmodium vivax of 7.32% (95% CI: 2.55-12.08; I² = 95.1%, p < 0.001). Resistance prevalence was higher in studies using both microscopy and PCR 7.32% (95% CI: 2.55-12.08), during the 2003-2009 study period 10.70% (95% CI: -1.24-22.65), and in the Oromia region 9.58% (95% CI: -0.41-19.58), while a 42-day follow-up reported a pooled prevalence of 17.91% (95% CI: -9.34-45.15). Chloroquine-resistant Plasmodium vivax is present in Ethiopia, with an overall prevalence of about 7%. Although resistance remains moderate, it is clinically significant and underscores the importance of ongoing surveillance, regular treatment monitoring, and consideration of alternative therapeutic approaches.