Seroprevalence of equine leptospirosis in Poland (2019–2023)

Abstract

AbstractBackground: Leptospirosis in horses is associated with various clinical signs, potentiallyleading to fatal outcomes. Additionally, the disease may pose a zoonotic risk toindividuals involved in handling infected animals. Implementing a serological monitoringprogramme in the equine population is one of the key tools used to reduce therisk of transmission of Leptospira infections to humans.Objectives: To provide new insights into the seroprevalence of leptospirosis indomestic horses in Poland.Study Design: Serological monitoring program.Methods: Data were collected from serological surveys of horse serum samplesacross 14 of the 16 provinces between 2019 and 2023. A total of 4474 horse serumsamples were tested using the microscopic agglutination test (MAT), with 8 Leptospiraserovars from 7 European serogroups. Statistical analyses and data visualisation wereperformed using Python-based libraries. Prevalence was calculated as absolute andrelative percentages. Pairwise prevalence comparisons employed chi-squared testswith adjustments for multiple comparisons. Bayesian posterior probabilities wereestimated to evaluate prevalence differences between groups.Results: The 5-year study showed a relatively high exposure (25.1%) of horses toLeptospira antigens in Poland. Dominant Leptospira serogroups were: Sejroe (39.2%),Pomona (14.6%), Bratislava (11.2%), and Grippotyphosa (10.1%). Pomorskie recordedthe highest percentage of positive samples (29.2%). Conversely, Lubuskie exhibitedthe lowest prevalence at 16.2%.Main Limitations: Details on the uses of horses were not available.Conclusions: This analysis provides valuable data on the circulation of Leptospira serogroupsacross different regions over time. The high seroprevalence of Leptospira inthe Polish horse population underscores the necessity of ongoing monitoring, whichwill aid in the protection of individual horses, herds, and humans from potentialinfections.