# Geospatial mapping and risk factor analysis of Leptospira interrogans serovar Canicola Portland Vere in backyard cattle in Chiapas, Mexico

## TL;DR

This study maps and analyzes the risk factors for Leptospira infection in backyard cattle in Mexico, identifying key factors like breed, water sources, and dog presence.

## Contribution

The study integrates serological surveillance, spatial mapping, and statistical modeling to identify epidemiological hotspots for Leptospira interrogans in backyard cattle systems.

## Key findings

- The overall seroprevalence of Leptospira was 27.72%, with the Portland Vere serovar being predominant.
- Cintalapa had the highest seroprevalence (61.75%), and risk factors included artificial insemination and specific cattle breeds.
- The presence of dogs was significantly associated with Portland Vere seropositivity.

## Abstract

Leptospirosis is a globally neglected zoonosis caused by pathogenic spirochetes of the genus Leptospira. It affects a wide range of animals and poses serious public and veterinary health risks. Backyard cattle systems, common across Latin America, are particularly vulnerable due to poor biosecurity and close animal–human–wildlife interfaces. This study assessed the seroprevalence, spatial distribution, and risk factors associated with Leptospira infection in backyard cattle herds of central Chiapas, Mexico.

A cross-sectional study was conducted from January to September 2022 across five municipalities. A total of 590 serum samples were collected and analyzed using the microscopic agglutination test with six serovars. The geographical coordinates of production units (PUs) were recorded using a Global Positioning System (GPS), and spatial analysis was conducted with ArcGIS 10.5. Risk factor associations were evaluated through Chi-square tests and multivariate logistic regression using RStudio and Statistical Package for the Social Sciences software.

The overall seroprevalence of Leptospira was 27.72% (95% confidence interval [CI]: 23.97%–31.75%), with the Portland Vere serovar being predominant (22.89%). Cintalapa exhibited the highest municipal seroprevalence (61.75%; odds ratio [OR] = 6.2). Logistic regression identified significant risk factors for seropositivity, including artificial insemination (OR = 2.43), use of Jagüey reservoirs (OR = 0.47), and cattle aged 3 years (OR = 0.54) or 8 years (OR = 1.98). The American Swiss × Holstein crossbreed was significantly associated with increased seroprevalence (OR = 3.15). The presence of dogs within PUs was significantly associated with Portland Vere seropositivity (OR = 3.82), highlighting a possible role in disease transmission.

This study highlights a high burden of Leptospira interrogans serovar Canicola Portland Vere in backyard cattle of central Chiapas. Key risk factors include specific breeding methods, water sources, age, and breed. The integration of serological surveillance, spatial mapping, and statistical modeling proved effective in identifying epidemiological hotspots and informing future One Health-based prevention strategies. The findings emphasize the need for enhanced disease surveillance, targeted control programs, and public health interventions tailored to small-scale cattle systems in tropical regions.