Exploring the burden of cholera in the WHO African region: patterns and trends from 2000 to 2023 cholera outbreak data

Abstract

Introduction: Cholera outbreaks remain persistent in the WHO African region, with an increased trend in recent years. This study analyses actual drivers of cholera including correlations with water, sanitation, and hygiene (WASH) indicators, and climate change trends.

Methods: This was a cross-sectional descriptive and analytic study. Cholera data from 2000 to 2023 and data relating to cholera drivers were compiled and analysed through multi-level exploratory analysis. We cross-referenced several WASH indicators, and generated a similarity matrix to categorise countries or subnational units into groups using principal component analysis and K-means clustering. We integrated cholera outbreak data with WASH indicators and created a matrix of indicators relevant for analysing cholera burden. We conducted summary statistics, temporal visualisations, Geographic Information System (GIS) mapping, trend analysis and statistical tests for correlations to derive patterns and trends from the data, derive similarities and develop projections.

Results: A total of 2 727 172 cases and 63 182 deaths were reported from 44 countries, representing 94% of the 47 countries in the region, from 2000 to 2023. The case fatality ratio of 2.3% is suggestive of issues in case management. A total of 684 outbreaks were reported, with the highest burdens in Nigeria and the Democratic Republic of the Congo. Median detection time to outbreak was 2 days, while median time for outbreak control was 92 days. Cholera incidence seemed higher in the period 2014 to 2023 than in the period before 2014. The study results confirmed correlations between WASH indicators and cholera outbreaks. Risks factors include drinking surface water, lacking soap and/or water, and open defaecation. Over 29% and 58.8% of the population lack access to basic water and basic sanitation, respectively.

Conclusion: Insufficient access to WASH services remains the main predisposing factor for cholera in the WHO African region. Political leaders should invest more in access to WASH, strengthen multisectoral collaboration, and improve availability of needed tools to increase the likelihood of meeting cholera elimination goals by 2030.

Keywords: Cholera; Control strategies; Epidemiology; Global Health; Public Health.

Figure 1. Trends of cholera outbreaks from 2001 to 2023, with number of cholera outbreaks and number of affected countries. CFR, case fatality rate

Figure 2. Total case rate and death rate.

Figure 3. Map of cholera outbreaks, cumulative cases, deaths, and CFR (2000–2023). CFR, case fatality rate.

Figure 4. Pattern of cholera disease burden using cumulative IDSR data of suspected cholera cases from 2019 to 2023. IDSR, integrated disease surveillance and response; non-AFRO MS,Non Member States of the WHO African Region.

Figure 5. Water, sanitation and hygiene coverage in the WHO AFRO region and sub region, 2015–2022.

Figure 6. Clustering of countries based on water, sanitation, and hygiene indicators.

Figure 7. Water sanitation and hygiene profile for the different clusters.

Figure 8. Water sanitation and hygiene profile for the different clusters. IDSR, integrated disease surveillance and response.