Glanders and brucellosis in equids from the Amazon region, Brazil.

This research article investigates the occurrence of glanders and brucellosis, two zoonotic diseases, in horses and mules on Marajó Island in Brazil. The findings of this study show a substantial presence of both diseases, marking the first reported instances in this region.

Research Objectives and Methodology

• The primary objective of this study was to investigate the occurrence of glanders and brucellosis in horses (Marajoara and Puruca breeds) and mules on a property in Soure, Marajó Island. The study was motivated by a significant reduction in the numbers of these animals, amidst concerns of precarious veterinary care, mysterious morbidity and mortality causes, and uncontrolled interbreeding with other horse breeds.
• The researchers collected serum samples from 388 animals, including 357 horses and 31 mules. These animals were kept in an extensive breeding system, which also bred buffaloes, goats, and sheep, allowing interactions among the species.
• The collected sera were then tested for glanders using an indirect ELISA (ELISAi), and the results were confirmed by immunoblotting. Meanwhile, a Rose Bengal test (RBT) was used to diagnose brucellosis, with confirmation through the Serum Agglutination test (SAT) and 2-mercaptoethanol test.

Findings and Implications

• The testing revealed that 9 out of 388 animals (2.31%) were positive for glanders in the ELISAi test. The test’s results were confirmed by immunoblotting in eight cases, leading to an overall seropositivity rate of 2.06% in the herd for this disease.
• In terms of brucellosis, serum samples from 26 out of 388 (6.7%) horses turned out reactive in the RBT. Of these, 18 had a titer of at least 50 and 8 had a titer of at least 100 in the SAT. This indicated an overall occurrence of brucellosis in the herd.
• This study was the first to report cases of glanders and equine brucellosis in Soure on Marajó Island and is crucial in monitoring these diseases. These diseases carry significant zootechnical and economic impacts on livestock and pose a considerable zoonotic risk to humans.
• The number of animals sampled in this study, coupled with their housing methods, is representative of the total equid population of the island. Combined with earlier studies on buffaloes, the findings indicate the endemic presence of these diseases on Marajo Island.