Effects of a Water, Sanitation, and Hygiene Program on Diarrhea, Cholera, and Child Growth in the Democratic Republic of the Congo: A Cluster-Randomized Controlled Trial of the Preventative Intervention for Cholera for 7 Days (PICHA7 WASHmobile) Mobile Health Program

Background We assessed whether the Preventative Intervention for Cholera for 7 Days (PICHA7) WASHmobile program reduced diarrhea and cholera serological responses and improved child growth in the Democratic Republic of the Congo (DRC). Methods The PICHA7 WASHmobile cluster-randomized controlled trial enrolled diarrhea patient households in urban Bukavu, DRC. Households were randomized into 2 arms: single in-person visit for the DRC government's diarrhea patient standard message on oral rehydration solution use and a basic water, sanitation, and hygiene (WASH) message (standard arm); or this standard message and the PICHA7 program with weekly voice and text mobile health (mHealth) messages and quarterly in-person visits (PICHA7 arm). The primary outcome was diarrhea in the past 2 weeks assessed monthly for 12 months. Secondary outcomes were healthcare facility visits for diarrhea, Vibrio cholerae serological response, stunting, underweight, wasting, and diarrhea with rice water stool over 12 months. A Vibrio cholerae serological response was defined by a rise in serum V. cholerae O1 O-specific polysaccharide (OSP) immunoglobulin A (IgA) or immunoglobulin G (IgG) from baseline to the 1-month follow-up. Generalized estimating equations were used for regression models to account for clustering at the individual and household level. Results Between December 2021 and December 2022, 2334 participants were randomly allocated to 2 arms: 1138 standard arm and 1196 PICHA7 arm. Diarrhea prevalence during the 12-month surveillance period was significantly lower among PICHA7 arm participants compared to standard arm participants (prevalence ratio, 0.39 [95% confidence interval {CI}:. 32-.48]). PICHA7 arm participants had lower odds of visiting a healthcare facility for diarrhea during the 12-month surveillance period (OR: 0.44 [95% CI:. 25-.77]) and lower odds of diarrhea with rice water stool (OR: 0.48 [95% CI:. 27-.86]). Significantly lower V. cholerae IgA serological responses were observed in the PICHA7 arm compared to the standard arm, defined by a change in serum IgA to V. cholerae O1 OSP from baseline to the 1-month follow-up (coefficient of between-arm difference from baseline to 1 month: -0.85 [95% CI: -1.60 to -.09]). PICHA7 arm children aged <5 years were significantly less likely to be stunted (52% vs 63% standard arm) (OR: 0.65 [95% CI:. 43-.99]) at the 12-month follow-up. All WASH components had high adherence. Conclusions The PICHA7 WASHmobile program, which combines mHealth with quarterly in-person visits, lowered healthcare facility visits for diarrhea, cholera serological responses, and stunting in the DRC. Clinical Trials Registration NCT05166850.