# Spatial analysis of human Coxiella burnetii infection and populations of goat and cattle in Korea, 2015-2024

## TL;DR

This study explores the spatial relationship between human Q fever cases and goat populations in Korea from 2015 to 2024, finding a strong correlation.

## Contribution

The study provides new evidence of a growing spatial correlation between goat populations and Q fever outbreaks in Korea.

## Key findings

- Human Q fever incidence showed significant positive spatial associations with goat populations in 2016 and 2021.
- The odds ratio of Q fever hotspots linked to goat populations increased over time.
- No significant association was found between Q fever and cattle populations.

## Abstract

Q fever is a bacterial zoonosis that occurs worldwide. Although several studies have reported associations between goat populations and human Q fever outbreaks in Korea, spatial correlation analyses remain limited. Therefore, this study examined the geographic correlation between human Q fever outbreaks and the distributions of goats and cattle in Korea.

This study covered a 10-year period (2015-2024), using each of the 250 districts in Korea as the unit of analysis. Data were divided into 2 time periods: 2015-2019 and 2020-2024. Hotspots for the standardized incidence ratio (SIR) were identified using Getis-Ord Gi*. Spatial correlations between SIR and goat and cattle populations were evaluated using a multivariable spatial error model, and the associations between hotspot variables and livestock abundance were assessed using a multivariable Leroux conditional autoregressive model.

SIRs for human Q fever showed significant positive spatial associations with goat populations in 2016 (coefficient=46.52, p<0.01) and 2021 (coefficient=70.97, p<0.01). The associations between goat populations (2016 and 2021) and hotspot classifications were consistent across both periods, with the odds ratio increasing from 1.87 (95% credible interval [CrI], 1.23 to 2.85) in 2015-2019 to 2.33 (95% CrI, 1.55 to 3.64) in 2020-2024. No significant associations were observed between human Q fever and cattle populations.

Goat populations are becoming more strongly spatially correlated with human Q fever incidence. These findings underscore the need for enhanced preventive management of goat farms to mitigate future outbreaks.