Prevalence and spatial distribution of Brucella spp. seropositive equids from the state of Mato Grosso, Brazil.

BACKGROUND

Brucellosis is a chronic infectious disease in equids, characterized by suppurative lesions in joints and bursae, with potential impacts on animal performance and public health.

OBJECTIVES

To investigate the prevalence and spatial distribution of Brucella spp. seropositive equids in the state of Mato Grosso, Brazil.

METHODS

A total of 3,858 serum samples from 3,230 horses, 602 mules, and 26 donkeys were analyzed using the Buffered Acidified Antigen Test (AAT) and Complement Fixation Test (CFT), following Brazilian Ministry of Agriculture guidelines. Samples were obtained from all municipalities and included the Amazon, Cerrado, and Pantanal biomes.

RESULTS

AAT screening identified 4.48% (173/3,858) reactive animals, of which 0.78% (30/3,858) were confirmed by CFT. The estimated prevalence was 0.82% (95% CI: 0.79-0.85%), with values of 0.91%, 0.88%, and 0.12% for the Amazon, Cerrado, and Pantanal biomes, respectively. No significant associations were found between seropositivity and age, sex, species, or management variables. Spatial analysis showed no evidence of clustering, indicating a homogeneous distribution of risk across the state. Additionally, no association was observed between equine seropositivity and bovine brucellosis foci.

CONCLUSION

Equine brucellosis showed low prevalence and a diffuse spatial pattern in Mato Grosso, supporting the role of equids as incidental hosts and reinforcing the need for continued epidemiological surveillance of interspecies transmission.