Prevalence and risk factors for bluetongue in the State of São Paulo, Brazil

• DOI: 10.1002/vms3.113
• Publication Date: 2018-07-02T11:52:08Z
• Authors: Thaís G. da Silva; Michele S. Lima; Massimo Spedicato; Irene Carmine; Liana Teodori; Alessandra Leone; Maira S. N. Martins; Fernando G. Buchala; Klaus S. Hellwig; Adriana H. de Cam...; Eliana De Stefano; Giovanni Savini; Edviges M. Pituco
• Keywords: 2. Zero hunger; seroprevalence; Veterinary medicine; Cattle Diseases; Original Articles; 04 agricultural and veterinary sciences; Serogroup; Bluetongue; 3. Good health; 0403 veterinary science; Cross-Sectional Studies; Logistic Models; Risk Factors; SF600-1100; Prevalence; Animals; Cattle; Animal Husbandry; Bluetongue virus; Brazil

AbstractBluetongue (BT), caused byBluetongue virus(BTV), is a disease that affects ruminants such as cattle, sheep, goats and deer. BTV is transmitted by female midges of the genusCulicoides. In Brazil, information on the prevalence of BTV in cattle is limited, so the objective of this work was to identify BTV serotypes in cattle. The State of São Paulo was divided into seven cattle‐producing regions, and in each of them, 300 cattle farms were randomly selected. One animal from each farm (out of a total of 1,598 farms) was selected and its sera tested by virus neutralization technique against BTV serotypes (1–24 and 26) for determining antibody titre. Moreover, for each sampled farm, an epidemiological questionnaire was submitted to verify the type of cattle production and the zootechnical and sanitary practices carried out, which could be associated with a higher risk of BTV infection. In this study, antibodies (percentage, [95% confidence interval]) were identified against 11 serotypes: BTV‐1 (22.15%, [15.72–27.92]), BTV‐2 (31.03%, [26.65–37.98]), BTV‐3 (18.96%, [12.42–24.90]), BTV‐4 (24.90% [19.41–29.12]), BTV‐9 (6.82%, [1.45–11.72]), BTV‐12 (7.50%, [2.82–12.51]), BTV‐17 (23.90%, [17.35–29.35]), BTV‐19 (10.20%, [4.62–5.56]), BTV‐21 (30.66%, [25.00–36.00]), BTV‐22 (12.14%, [5.91–18.55]), BTV‐26 (57.00%, [51.41–63.59]). In this study, for the first time in Brazil serological evidence of the presence of serotypes BTV‐2, BTV‐9, BTV‐21 and BTV‐26 is reported. The variable ‘new cattle entering herd’ was considered a risk factor for the occurrence of infection (OR = 2.183, 95% CI = 1.6–2.9).