Detection of Antibodies Against Leptospira interrogans Serovars Among Stabled Horses in Qazvin Province of Iran as a One-Health Concern.

Leptospirosis, a global zoonotic disease caused by pathogenic Leptospira spp., poses significant health risks to both animals and humans. This study aimed to assess the seroprevalence of antibodies against Leptospira interrogans serovars in stabled horses in Qazvin province, Northwest Iran. From January 2023 to April 2024, a total of 83 blood samples were collected from asymptomatic horses using the microscopic agglutination test (MAT). Results indicated a seroprevalence of 40.96% (95% CI: 31-52), with notable variations among regions: 38.89% (95% CI: 27-52) in Qazvin, 38.46% (95% CI: 18-64) in Alborz and 50% (95% CI: 28-72) in Takestan. The Hardjo serovar was most prevalent (21.68%, 95% CI: 14-32), followed by Icterohaemorrhagiae (13.25%, 95% CI: 7-22) and Canicola (7.22%, 95% CI: 3-15). Statistical analysis revealed significant associations between seropositivity and factors such as the presence of domestic animals and housing conditions. Notably, adult horses exhibited higher seropositivity compared to younger ones. This study highlights the potential role of horses as reservoirs for Leptospira, particularly the Hardjo serovar, suggesting a zoonotic risk to humans and underscoring the need for effective surveillance and control measures in equine populations.