START Research Assistant presents findings at the International Convening on Diarrheal Diseases Surveillance

In February 2026, START research assistant (RA) Sofia Donovan was invited to present the preliminary findings of a systematic review on diarrhea-attributable mortality in children under 5 years old in Low- and Middle-Income Countries (LMICs) at the International Convening on Diarrheal Diseases Surveillance (ICDDS) in Goa, India. The ICDDS is a global gathering to discuss scalable diagnostic solutions, optimal control strategies, and sustainable surveillance networks. With current and future changes to the global health financing landscape, there is an increasing need for disease surveillance to be led and financed by countries. Diarrhea surveillance is important because it provides critical evidence needed to prevent deaths; develop, design, and target interventions; mobilize resources; and strengthen health systems, particularly for young children and vulnerable populations. This convening brought together leading researchers and surveillance practitioners to chart a path forward towards sustainable diarrhea surveillance.

There has been tremendous progress over the last 25 years in reducing diarrheal deaths thanks to factors including improved access to oral rotavirus vaccines and oral/intravenous rehydration therapy. Nevertheless, diarrhea deaths remain an important cause of mortality in LMICs. There are open questions about the relative importance, geographical/age distribution, and temporal trends of diarrheal deaths. In October 2025, the START Center was tasked by the Enterics, Diagnostics, Genomics & Epidemiology (EDGE) team at the Gates Foundation to synthesize published evidence and compare evidence sources to describe the proportion of under 5 mortality in LMICs attributed to diarrhea, and time trends for diarrheal deaths in under 5 children living in LMICs. The core aim of this work is to identify and interrogate differences between evidence sources to ensure decisions and resources being allocated reflect a comprehensive empirical understanding of diarrhea’s contribution to under 5 mortality. Sofia, START RA and project manager for this engagement, presented the preliminary project findings, impressions of the data, and gaps and challenges the team has encountered so far. Preliminary findings are broadly consistent with existing estimates, despite differing methodologies and data sources. Sofia called out that age group definition substantially influencing reported proportions, with proportions being markedly higher when neonates are excluded. Sofia also shared that methodological decisions (inclusion criteria, age structure and attribution methods) can meaningfully influence proportions and shape estimates.

The START team’s complete review will clarify how published study-level estimates of proportionate diarrhea-attributable under 5 mortality compare across settings and align with existing global estimates.