# Spatial modeling of soil-transmitted helminthiases in Colombia under climate change scenarios

## TL;DR

This study models how climate change might increase soil-transmitted worm infections in Colombia by 2035 and shows how public health actions can reduce this risk.

## Contribution

The study introduces a spatial modeling approach to project helminthiasis prevalence under climate change and intervention scenarios in Colombia.

## Key findings

- Baseline infection rates were highest in Amazonia and the Sierra Nevada de Santa Marta.
- Projected prevalence increases under climate change were reduced by interventions like drug administration and improved sanitation.
- Temperature and humidity strongly influenced infection transmission, while altitude and forest cover had negative effects.

## Abstract

Soil-transmitted helminthiases remain a significant public health burden in Colombia, especially in rural and tropical areas. Climate change is expected to alter environmental conditions that favor the survival and transmission of Ascaris lumbricoides, Trichuris trichiura, and hookworms.

To estimate the current spatial distribution of these infections and project prevalence changes by 2035 under climate change scenarios, with and without public health interventions.

An ecological study with spatial modeling was conducted, integrating epidemiological, climatic, and biological data. Baseline prevalence data were obtained from the Encuesta Nacional de Parasitismo Intestinal (2012-2014). Climate projections from the ERA5-Land satellite product (2024-2035) were used alongside generalized additive models to estimate environmental suitability. A systematic review defined optimal temperature and humidity thresholds for the development of infective stages. Two scenarios were modeled: one without intervention and another with mass drug administration and improved sanitation.

Baseline prevalence was 11.3% for A. lumbricoides, 18.4% for T. trichiura, and 6.4% for hookworms, with highest rates in Amazonia and the Sierra Nevada de Santa Marta. In a no-intervention scenario, projected prevalences increased to 13.6, 21.2, and 8.0%, respectively. The intervention scenario reduced these to 6.8%, 12.7%, and 5.6%. Temperature and humidity were strong positive predictors (p < 0.01), while altitude and forest cover showed negative associations.

Climate change may intensify soil-transmitted helminthiases transmission in Colombia by 2035. However, sustained control strategies could significantly mitigate this impact. Spatial modeling offers a valuable tool to guide targeted interventions and inform public health planning.