Water and sanitation access shapes cholera burden in low- and middle-income countries

The United Nations Sustainable Development Goals (UN SDG) include targets for safe drinking water, sanitation, and hygiene (WASH), which are critical in preventing cholera, a persistent health threat in low- and middle-income countries (LMICs). We aimed to assess the attributable burden of WASH on cholera under the UN SDG framework to inform global control efforts. We extracted cholera-related information along with socioeconomic, geographical, and climate data across 89 LMICs from 2000 to 2017. Genome data from Enterobase and World Health Organization (WHO) weekly reports, were utilized to identify cholera occurrence. A modified Poisson generalized additive mixed model (GAMM) was employed to investigate the impact of WASH access on cholera, and the attributable burden and prevention fraction were further estimated. Statistically significant protective effects against cholera were observed for improved WASH facilities (e.g., piped water: prevalence ratio, PR=0.88, 95% CI: 0.85-0.91), while harmful effects were noted for unimproved facilities (e.g., open defecation: PR=1.09, 95% CI: 1.06-1.12). Regional disparities in WASH access further contributed to unequal cholera burden. In Sub-Saharan Africa, 25.77% of cholera occurrences were attributed to the high proportion of unimproved drinking water, much higher than 9.09% in Northern Africa and Western Asia. Achieving universal access to improved sanitation could reduce cholera risk by 32.98% in Sub-Saharan Africa, compared to 7.47% in Central and Southern Asia. Our findings highlight the need for maintaining and increasing access to safe WASH in cholera-affected countries, and offer comprehensive information for implementing targeted, local-level control approaches to end cholera globally. • Proportions of piped water and sewer/septic sanitation negatively relate to cholera. • Proportions of surface water and open defecation positively correlate with cholera. • Regional disparities in WASH access contributed to inequalities in cholera burden. • Achieving 100% access to safe WASH in UN SDG targets would reduce cholera risk.