Geospatial analysis and prevalence estimation of household drinking water treatment in sub-Saharan African countries: insights from recent demographic and health surveys

In sub-Saharan countries, where a large number of populations depend on unsafe water, household water treatment is the recommended means to improve and maintain the safety and quality of water. Boiling, adding bleach, filtration, solar disinfection, straining through cloth, and settling are among well-known treatment methods. However, the practice in the region is very low. The current study is intended to assess the spatial analysis and scope estimation of households’ water treatment methods in sub-Saharan African countries. The Demographic and Health Survey (DHS) data were collected from 2012 to 2024 in 34 sub-Saharan countries, encompassing 500,845 households and 20,492 clusters. Global spatial autocorrelation was performed to analyze whether the pattern of household water treatment is clustered, dispersed, or random across the study areas. Once a positive global autocorrelation was confirmed, a local spatial autocorrelation analysis (Getis-Ord Gi* statistics) was employed to detect local clusters. ArcGIS version 10.7 was used to map the clusters, and Kulldorff SaTScan version 10.0.2 software, using the Bernoulli model, was used for spatial scan statistical tests. The geo-statistical ordinary Kriging spatial interpolation technique was used to predict unsampled areas based on sampled clusters. The overall prevalence of household water treatment across sub-Saharan Africa between 2012 and 2024 was 20% (95% CI: 19.7%–20.0%). Reported treatment methods included boiling (9.04%), bleaching (6.98%), filtration (0.90%), solar disinfection (0.07%), straining through cloth (2.54%), settling (1.59%), and other methods (0.62%). Regarding treatment adequacy, 16.98% of households used adequate methods, 4.75% used inadequate methods, and 0.99% used both. Spatial analysis showed clear clustering of household water treatment practices, with hotspots identified in Madagascar, Uganda, Rwanda, Kenya, Tanzania, Burundi, Malawi, Zambia, Burkina Faso, Mali, Liberia, and Sierra Leone. SaTScan cluster analysis identified 78 significant windows across the region. The low prevalence of household water treatment across sub-Saharan Africa underscores a substantial barrier to achieving Sustainable Development Goal 6.1. To address this, efforts should focus on improving access to affordable and context-appropriate household water treatment technologies, implementing community-level health education and behavior change programs to promote correct water treatment practices, and targeting hotspot regions identified in the spatial analysis with coordinated interventions from governments, NGOs, and partners. These strategies are essential to reduce waterborne diseases and accelerate progress toward universal access to safe drinking water.