THE IMPACT OF THE GILGEL GIBE III HYDROELECTRIC POWER DAM ON MALARIA TRANSMISSION IN THE LOMA BOSSA DISTRICT, SOUTHWEST ETHIOPIA

Abstract

Malaria is a vector-borne protozoan disease caused by species in the genus Plasmodium. Its vector requires water bodies as the breading habitat. Ethiopia has hydroelectric power Dams, including the Gilgel Gibe-III, which may facilitate malaria transmission. However, no malaria research has been conducted in the stated dam area. Therefore, this study assessed the malaria transmission pattern in nearby areas of the Gibe-III hydroelectric power Dam in Loma Bossa District, Southwest Ethiopia. A community-based crosssectional study was conducted from January to March and June to August 2023. The study sites were clustered within 3 kilometers, 3-5 kilometers, and 5-6 kilometers from the Gibe-III hydroelectric power Dam. Blood samples were collected from 317 individuals in 68 households. Both thick and thin blood smears were prepared and examined under microscopy. Risk factors and socio-demographic characteristics were collected using questioner. Additionally, health facility based retrospective data was gathered from log books at Addis Boderi Health Center from September 2013 to August 2015 before Dam construction and September 2015 to August 2023 during and after Dam construction. The overall malaria prevalence is this study area was 10.1% (32/317) (95% CI: 7.0-14.0). The prevalence of malaria in <3km, 3-5km, and 5-6km was 18.6%, (8/43), 10.9% (20/185), and 4.4% (4/89), respectively. Overall Plasmodium falciparum rate was 7.5% (24/317) followed by Plasmodium vivax 2.5% (8/317). Under 5 years old children (22.7%; 5/22) were at higher risk for malaria (AOR: 6.4, 95% CI: 1.8-22.7, P=0.004) than others. Residents at a distance of <3km from the Dam were more infected than 5-6km (AOR: 6.3, 95% CI: 1.6-23.7, P=0.007). In the retrospective data analysis, the trends of malaria transmission was higher at <3km (50.8%; 1341/2642), compared with distances of 3-5km (29.5%; 2155/7317) and 5-6km (11.9%;457/3828) like that of cross-sectional study. The residents at a nearby distance from the power Dam were at increased risk of malaria. Therefore, special attention during malaria control programs should be given for those who reside near dams and children less tha five years old