Evaluating the effectiveness & costs of strategies post-eradication to monitor for freedom from BVDV infection in Ireland

ContextIn Ireland, a national Bovine Viral Diarrhoea (BVD) eradication programme has been effective in reducing national prevalence and has recently been approved by the European Commission. In anticipation of achieving freedom, there is an ongoing discussion regarding appropriate strategies post-eradication to monitor for continued freedom from Bovine Viral Diarrhoea Virus (BVDV) infection of the national cattle sector.ObjectiveThe objective of this study is to evaluate the trade-off between the performance of different testing protocols and their associated costs in monitoring BVDV post-eradication in the national cattle sector. By assessing various testing strategies, including bulk tank milk (BTM) testing, first lactation check tests (FLCT), abattoir tests, and youngstock check test (YSCT), the aim is to provide informed input for implementing a long-term sustainable monitoring strategy.MethodsIn this study, we apply alternative testing protocols to a modelled cattle population in County Kerry, a region with a bovine population considered to be representative of the entire Irish population. The analysis incorporates combinations of Bulk Tank Milk (BTM) testing First Lactation Check tests (FLCT), abattoir tests, and Young Stock Check Testing (YSCT). The YSCT, which focuses on high-risk herds by collecting blood samples from young, homebred animals between nine and 18 months of age, was a key component of the analysis.Results and conclusionsAll tested protocols are capable of timely detection of a BVDV outbreak, with detection times of less than one year. Our results highlight the impact of reducing herd coverage by YSCT on post-eradication surveillance for BVDV freedom. By evaluating the trade-off between increased costs and shortened time to detection, this study provides valuable insights for selecting an appropriate monitoring policy in post-eradication programmes.SignificanceThe findings of this study offer guidance on balancing costs and detection e