Bovine neosporosis in Rio Grande do Sul, Brazil: Elevated antibody detection rate in comparison to previous decades

Abstract

Roman I.J., Rosa G., Rodrigues F.S., Cargnelutti J.F., Sangioni L.A. & Vogel F.S.F. 2024. Bovine neosporosis in Rio Grande do Sul, Brazil: Elevated antibody detection rate in comparison to previous decades. Pesquisa Veterinária Brasileira 44:e07476, 2024. Graduate Program in Veterinary Medicine, Laboratório de Doenças Infecciosas e Parasitárias, Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil. E-mail: fernanda.vogel@ufsm.br This study aimed to determine the frequency of anti-Neospora caninum antibody detection in three samples and sampling methods: A prevalence study, routine diagnostic laboratory samples, and fetal bovine serum samples. These samples were collected from cattle in Rio Grande do Sul (RS), southern Brazil, and analyzed using the indirect immunofluorescence reaction technique. For each sampling method, a historical study was used as a reference for comparison. In the prevalence study, 1,248 serum samples were collected from 2020 to 2022. The prevalence of N. caninum in the RS state was 22.8% (285/1248). This figure was statistically different compared to previous studies conducted in 2002, which reported a prevalence of 11.2% (p<0.001). In the routine diagnostic samples, an average rate of 29.95% (985/3289) of anti-N. caninum antibodies were detected. This rate was statistically higher than that of a previous study conducted in 2003, which reported a rate of 20% (p=0.01). Similar data were found in the fetal bovine serum samples, which showed an increase compared to previous studies conducted in 2010 that reported a rate of 15% (p=0.003). The increase in the detection rate of N. caninum antibodies underscores the need for measures to control and prevent bovine neosporosis.