Introducing the Stool Stomper: A Device Designed to Enable Accelerated and Standardized Stool Sample Preparation Using the Kato–Katz Technique

Abstract

Soil-transmitted helminths (STHs) are parasitic worms that impact over 1.5 billion people globally. The Kato–Katz technique analyzes stool samples for STHs, allowing for individual diagnoses of STH infection and the estimation of community-level prevalence. One challenge that arises with the procedure is that lab technicians often struggle to prepare microscope slides of sufficient quality for analysis after one attempt. As a result, Kato–Katz procedures are repeated, wasting time and resources. To aid technicians during in-field slide preparation, we created the Stool Stomper. The Stool Stomper is a user-friendly, handheld mechanical device that applies constant, uniform pressure to stool samples to ensure standardized sample preparation onto microscope slides to improve egg counts. The Stool Stomper was assessed using artificial eggs during in-country testing in a lab setting in Dodoma, Tanzania, by lab technicians with various experience levels, from beginner to advanced. Compared to the traditional method, we found that the Stool Stomper reduced slide preparation time, reduced artificial egg counting time, and standardized artificial egg counts with more consistent and accurate readings. The current pilot study highlights the potential for future development and integration of the Stool Stomper device into the Kato–Katz technique to improve community-based STH treatment.