Identification of persistent clusters and temporal trends of glanders in horses throughout Brazil.

Abstract

Glanders, caused by Burkholderia mallei, is a zoonotic disease with profound socioeconomic and public health implications, affecting equines and humans. This study investigated glanders cases in Brazil from 2006 to 2023 to identify persistent clusters and analyze temporal trends, providing a foundation for the formulation of effective control policies. Official data were obtained from the National Animal Health Information System (SIZ) and Brazilian Institute of Geography and Statistics (IBGE), encompassing case notifications and equine population statistics by state and year. The incidence risk (IR) was calculated, and prospective spatiotemporal analyses were performed using the discrete Poisson model in SatScan software. Temporal trends were assessed through segmented regression in Joinpoint software. A total of 2,654 glanders cases were reported, with the Northeast region accounting for 52.19% of cases and Pernambuco presenting the highest IR (342.58/100,000). Primary clusters were detected in the Northeast (RR = 5.16), while secondary clusters were identified in the North, South, Central-West, and Southeast regions, with the most notable cluster in Amazonas (RR = 60.32). Temporal trend analysis revealed overall stability in Brazil but demonstrated increasing trends in the North, South, and Central-West regions. These results underscore the critical need for integrated epidemiological surveillance, stricter health regulations, and improved control of equine movement, particularly in regions at higher risk. Strengthening early diagnostic capabilities and implementing targeted educational initiatives are essential to curbing the spread of B. mallei and mitigating the socioeconomic and public health impacts of glanders in Brazil.