Journal Article

Resurgence of malaria in the Amhara Region, Ethiopia (2014–2024): trends, spatial expansion, and control challenges

Yenesew, Muluken Azage, Gelaye, Kassahun Alemu, Muchie, Kindie Fentahun, Engedaw, Hailemariam Awoke, Nigussie, Teshager Zerihun, Asemahagn, Mulusew Andualem, Lake, Mastewal Worku

2025

Overview

Background Despite substantial control gains over the past 2 decades, malaria remains a major public health threat in Ethiopia. The Amhara Region has recently experienced a significant resurgence, threatening to reverse previous progress. However, comprehensive analyses of this resurgence integrating long-term trends, parasite species dynamics, and spatiotemporal patterns are limited. Therefore, this study examines trends, spatial expansion, and control challenges associated with malaria resurgence in the Amhara Region. Methods A retrospective analysis of 11 years (January 2014–December 2024) of weekly malaria surveillance data from 166 districts in the Amhara Region, Ethiopia. Joinpoint regression was employed to detect significant temporal trend changes. A resurgence threshold was defined a priori as a ≥ 20% increase in cases compared to the 3-year average baseline for the same period (Sep–Dec 2021–2023), based on an expert consensus survey. Auto-regressive integrated moving average modelling was used to characterize and forecast the test positivity rate (TPR). The Getis-Ord Gi* statistic was used to identify spatial clustering and detect transmission hotspots. Results During the study period, 7,710,733 malaria cases and 162 deaths were reported. Adults (≥ 15 years) contributed 62% of cases. A single trend inflection point occurred in late 2018, marking a shift from a significant decline (Annual Percent Change [APC]: −13.2%) to a sharp resurgence (APC: + 12.6%, 2018–2024). The Annual Parasite Incidence (API) rose from 10.9 (95% CI 10.8–11.0) per 1000 in 2018 to 74.8 (95% CI 74.72–74.93) per 1000 in 2024. Plasmodium vivax became increasingly prominent, with its contribution to the total case burden rising from 25 to 43% (χ 2  = 190,789.55, p < 0.001). Its incidence surged 11-fold between 2018 and 2024 (from 2.7 to 32.4 per 1000). TPR increased from 10% (2018) to > 50% during peak months by 2024. In 2024, a resurgence occurred in 83% of districts; hotspots expanded into urban centres and previously low-transmission highland areas. Conclusion The Amhara Region is experiencing a malaria resurgence characterized by intensified transmission, geographic expansion into urban and highland areas, and a significant shift toward Plasmodium vivax dominance. These findings exemplify an \"elimination-resurgence paradox,\" where prior success increases vulnerability to threats such as invasive vectors, conflict, and climate shifts.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adolescent / Adult / Biodiversity hot spots / Biomedical and Life Sciences / Biomedicine / Blood parasites / Child / Child, Preschool / Disease hot spots / Disease transmission / Elimination of infectious diseases of poverty as a key contribution to achieving the SDGs / Emerging communicable diseases / Entomology / Epidemiological transition / Ethiopia / Ethiopia - epidemiology / Female / Health risks / Hot spots / Human diseases / Humans / Incidence / Infant / Infectious Diseases / Insecticides / Malaria / Malaria - epidemiology / Malaria - prevention & control / Malaria resurgence / Malaria, Falciparum - epidemiology / Malaria, Falciparum - prevention & control / Malaria, Vivax - epidemiology / Malaria, Vivax - parasitology / Malaria, Vivax - prevention & control / Male / Microbiology / Microscopy / Middle Aged / Parasites / Parasitology / Plasmodium vivax / Plasmodium vivax - physiology / Public Health / Retrospective Studies / Risk factors / Spatial epidemiology / Spatio-Temporal Analysis / Statistics / Surveillance / Transmission hotspots / Trends / Tropical Medicine / Vector-borne diseases / Vectors / Young Adult