Risk factors associated with the occurrence of antibodies against bluetongue virus in sheep in the state of Paraná, Brazil

Abstract

Bluetongue is an arbovirus that affects different animal species, being most relevant in sheep because of the possible disease severity. This study aimed to evaluate the occurrence of antibodies against bluetongue virus (BTV) in sheep in the central-western region of Paraná, Brazil, and the risk factors for infection in the species. This is the first study to determine these factors in the southern region of Brazil. A serological survey using agar gel immunodiffusion was positive in 28.1% (108/350) of the animals tested, and 91.66% (11/12) of the farms analyzed had at least one seropositive animal. Furthermore, contact between sheep and cattle was determined as the main risk factor for BTV infection in sheep, followed by flooding, a history of abortion, and contact with rivers and riparian forests. In conclusion, the occurrence of anti-BTV antibodies in flocks in Paraná was moderate however, the virus is still circulating in these animals, so greater epidemiological surveillance and implementation of programs to control the disease are necessary.