Evidence Hub

Development, field-testing and optimization of tools to quantify soil-transmitted helminths in fecal sludge from school pit latrines in Ethiopia

Tiruneh A, Mekonnen Z, Roose S, Ayana M, Vande Velde F, Mrimi EC, Gilleard JS, Templeton MR et al.

PLoS neglected tropical diseases, 2026

52 participants

Abstract

Background: Surveys to monitor large-scale deworming programs against soil-transmitted helminthiases (STH) involve collection and examination of stool samples from schoolchildren. These surveys are resource demanding and interrupt school activities. A potentially cost-saving alternative that does not involve children is to process fecal sludge samples from school pit latrines. As a first step towards a proof-of-principle of latrine-based monitoring of STH programs, we optimized tools to collect fecal sludge and to quantify STH eggs in the samples.

Methods: First, we developed and field-tested three locally made fecal sludge sampling prototypes. Second, we developed a modified egg counting method and conducted spiking experiments to explore its analytical performance. Third, we estimated the variation in egg counts in fecal sludge samples that were collected from six primary schools in Ethiopia at different pit latrine depths used by boys and girls and that were repeatedly examined. Finally, field data was used to inform an egg count simulation model to quantify the variation in egg counts and to determine the sampling and analysis strategies that resulted in surveys as precise as stool-based surveys.

Results: The modified fecal sludge sampling prototypes were generally successful, except for a few pit latrines with dried/solid fecal sludge and insufficient sludge volume. The egg counting method had moderately high analytical sensitivity that varied across the consistency of…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free