Seroprevalence of equine leptospirosis in Connecticut, US.
4 affiliations
- 1Department of Pathobiology and Veterinary Science, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT, U.S.
- 2United States Department of Agriculture, Infectious Bacterial Diseases Research Unit, ARS, Ames, IA, U.S.
- 3Department of Pathobiology and Veterinary Science, Connecticut Veterinary Medical Diagnostic Laboratory, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT, U.S.
- 4Department of Pathobiology and Veterinary Science, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT, U.S.. [email protected].
Abstract
Background
Leptospirosis is a geographically widespread neglected zoonotic disease caused by pathogenic spirochetes of the Leptospira genus. Horses can act as subclinical reservoir hosts, which are characterized as asymptomatic carriers that persistently excrete leptospires through their urine and transmit the disease. Horses play an important role in the lives of Connecticut (CT) residents in the form of leisure pursuits and related business activities. Nevertheless, there is a limited understanding of horse exposure to Leptospira in CT. This investigation sought to determine the prevalence of anti-Leptospira antibodies in horses in Connecticut, US. A total of 397 sera were tested by the microscopic agglutination test (MAT). The antigen panel included 40 strains representing 26 serogroups and four autochthonous isolates (not determined serogroup).Results
The overall horse seropositivity (established as a titer ≥ 1:100) was 61.5% (244/397). The most detected serogroups were Djasiman, Grippotyphosa, Australis, Pomona, Icterohaemorrhagiae, and serovar Room22 strain GWTS1. Cross reaction for more than one serogroup was found in 80/244 (32.8%). As a limitation, the MAT does not differentiate between natural exposure and vaccination. However, Leptospira bacterin for horses includes only serogroup Pomona in the U.S. Therefore, after eliminating Pomona results to reduce potential vaccination bias, the seroprevalence was 204/397 (51.4%).Conclusion
Our results showed a high seroprevalence of leptospirosis in Connecticut and strong evidence that animals were potentially exposed to serogroups/serovars not included in commercial bacterins. Further studies to attempt isolation and genotyping of the pathogen from horses are necessary to better understand the role of horses in the epidemiology of leptospirosis. This information will support diagnostic strategies, vaccine recommendations, risk assessment, and public health actions that can reduce spillover transmission and the impact of this important zoonotic disease.
Related
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- [Factors associated with seroprevalence of Toxoplasma gondii infection in pregnant women: a cross-sectional study, Piraquara, Brazil, 2024].
- Unravelling of Leptospirosis in the Humid Subtropical Climate of the Eastern Part of Northern India.
BibTeX
@article{hamond2026seroprevalence,
title = {{Seroprevalence of equine leptospirosis in Connecticut, US.}},
author = {Camila Hamond and Candace L Kangas and Vivianne W Lee and Anayah Fanfan and Jarlath E Nally and Holly McGinnis and Maureen Sims and Guillermo R Risatti and Elsio Augusto Wunder},
journal = {BMC veterinary research},
year = {2026},
month = aug,
doi = {10.1186/s12917-026-05749-5},
url = {https://europepmc.org/article/MED/42958252},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Seroprevalence of equine leptospirosis in Connecticut, US.
AU - Camila Hamond
AU - Candace L Kangas
AU - Vivianne W Lee
AU - Anayah Fanfan
AU - Jarlath E Nally
AU - Holly McGinnis
AU - Maureen Sims
AU - Guillermo R Risatti
AU - Elsio Augusto Wunder
PY - 2026
DA - 2026/08/01
JO - BMC veterinary research
DO - 10.1186/s12917-026-05749-5
UR - https://europepmc.org/article/MED/42958252
AB - Background Leptospirosis is a geographically widespread neglected zoonotic disease caused by pathogenic spirochetes of the Leptospira genus. Horses can act as subclinical reservoir hosts, which are characterized as asymptomatic carriers that persistently excrete leptospires through their urine and transmit the disease. Horses play an important role in the lives of Connecticut (CT) residents in the form of leisure pursuits and related business activities. Nevertheless, there is a limited understanding of horse exposure to Leptospira in CT. This investigation sought to determine the prevalence of anti-Leptospira antibodies in horses in Connecticut, US. A total of 397 sera were tested by the microscopic agglutination test (MAT). The antigen panel included 40 strains representing 26 serogroups and four autochthonous isolates (not determined serogroup).Results The overall horse seropositivity (established as a titer ≥ 1:100) was 61.5% (244/397). The most detected serogroups were Djasiman, Grippotyphosa, Australis, Pomona, Icterohaemorrhagiae, and serovar Room22 strain GWTS1. Cross reaction for more than one serogroup was found in 80/244 (32.8%). As a limitation, the MAT does not differentiate between natural exposure and vaccination. However, Leptospira bacterin for horses includes only serogroup Pomona in the U.S. Therefore, after eliminating Pomona results to reduce potential vaccination bias, the seroprevalence was 204/397 (51.4%).Conclusion Our results showed a high seroprevalence of leptospirosis in Connecticut and strong evidence that animals were potentially exposed to serogroups/serovars not included in commercial bacterins. Further studies to attempt isolation and genotyping of the pathogen from horses are necessary to better understand the role of horses in the epidemiology of leptospirosis. This information will support diagnostic strategies, vaccine recommendations, risk assessment, and public health actions that can reduce spillover transmission and the impact of this important zoonotic disease.
SN - 1746-6148
ER -