Prevalence and intensity of Schistosoma mansoni infection, and contributing factors in Alamata district of Tigray Region, Northern Ethiopia

Abstract

Background: Intestinal schistosomiasis caused by Schistosoma mansoni continues to be a significant public health problem in Ethiopia. This study investigated the prevalence and intensity of S.mansoni infection, and contributing factors in Alamata district of Tigray Region, Northern Ethiopia.

Methods: A community-based cross-sectional study was conducted and 1762 participants were enrolled from five clusters in Alamata district. A questionnaire was used to collect socio-demographic data and risk factors. Stool samples were examined using Kato-katz technique to determine the prevalence and intensity of infection. The data were analyzed using SPSS version 25. Median, inter quartile range (IQR), mean, frequency, and percentage were used to descriptively summarize data. The Wilcoxon Mann-Whitney and Kruskal-Wallis tests were used to compare the differences in mean rank of egg load between different groups. Bivariate and multivariable logistic regression models were used to investigate the association between the odds of being infected with S.mansoni and the different socio-demographic and other factors. The strength of these associations was reported using odds ratio with corresponding 95% confidence intervals, and a P-value below 5% was used to report statistical significance.

Results: Out of 1762 residents included in the study 941 (53.4%) were females. The age varied from 5-80 years, with a median age of 25 years (IQR = 27), the overall prevalence of S.mansoni was 21.5% with males accounting for 26% (204/821) of the infections. The proportion of infection was higher among the age groups of 15-19 and 20-29 years at 32.7% and 33.1%, respectively. The mean egg count among the infected study participants was 146.82 eggs per gram of feces (epg) ± (243.17 SD). Factors significantly associated with increased odds of infection were living in Waja cluster (AOR:8.9; 95% CI, 3.5-23.2; P< 0.001); being in the age groups 10-14 (AOR:6.0, 95% CI: 3.1-11.7, P<0.001), 15-19 (AOR:5.8, 95% CI:2.8-12.2, P<0.001), and 20-29 (AOR:3.5, 95% CI:1.8-6.8; P<0.001) years; having direct contact with water while crossing river (AOR: 2.4, 95% CI: 1.5-3.8, P<0.001); and swimming (AOR: 1.4, 95% CI: 1.01-2.0, P = 0.035).

Conclusion: The study indicates a notable S.mansoni burden in the area, driven by various risk factors. To effectively address this, enhancing diagnostics, implementing targeted mass drug administration, and conducting comprehensive health education campaigns on disease transmission routes are imperative.

Fig 1. Map of Alamata district (Map was created using ArcGIS Pro 3; shapefile source is Diva-GIS, available at https://diva-gis.org/).

Fig 2. Schematic presentation of the sampling procedure (Created using BioRender).

Fig 3. Distribution of S.mansoni by cluster.