Geostatistical modelling of soil-transmitted helminth prevalence in Kenya: Informing targeted interventions to accelerate elimination efforts

Abstract

Objectives

This study estimates the prevalence of soil-transmitted helminths (STH) in Kenya, identifying high- and low-burden communities to optimize intervention strategies.

Methods

Using prevalence data from 146,668 children in 3752 schools across 207 sub-counties in Kenya, collected in 2021 and 2024, alongside environmental and socio-economic data, we modelled the prevalence of hookworm, Ascaris lumbricoides and Trichuris trichiura at a 5 × 5 km resolution. We estimated the probability of exceeding predefined prevalence thresholds (2%, 10% and 20%) and the population-weighted mean prevalence for each species.

Results

Hookworm prevalence was low (mean of 0.6%, 95% credible interval [CI] 0.1%-2.9%), with 6% of sub-counties, primarily in coastal regions, exceeding the 2% threshold. T. trichiura prevalence was higher (mean 1.4%, 95% CI 0.2%-7.3%), with elevated risk in southwestern and coastal regions. A. lumbricoides was highest (mean 2.8%, 95% CI 0.1%-11.6%), clustering in western Kenya. Across all species, the probability of exceeding the 20% prevalence threshold remained below 0.5.

Conclusion

These findings underscore persistent STH transmission in some regions, necessitating region-specific treatment approaches, including strategic decisions on drug selection, target populations and optimized treatment frequency to achieve Kenya’s STH elimination targets.