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.