Longitudinal monitoring of cattle infected by bluetongue virus serotype 3 on a commercial Holstein dairy farm in the Netherlands

Abstract Since September 2023, bluetongue virus serotype 3 has been circulating in the Netherlands. Cattle can exhibit a range of clinical signs from sub‐clinical to severe, but they are also known to play an important role as a virus reservoir in bluetongue epidemics. We closely monitored an outbreak on a commercial dairy herd by daily clinical inspection, sensor data and longitudinal biweekly real‐time PCR testing. PCR testing was performed on 18 cattle from the start of the bluetongue virus serotype 3 outbreak until two consecutive blood samples tested negative, 24–28 weeks after the start of the monitoring. In conclusion, this case study has shown that sensor data can contribute to detecting bluetongue virus serotype 3‐infected cattle. Furthermore, it appeared that the majority of cattle remained positive by real‐time PCR for approximately 6 months from the start of the infection.