In order to avoid biased estimation of the sensitivity and specificity, the results were reported under two scenarios. sensitivity of three different assays used in SBV antibody detection using control sheep samples of determined status. After obtaining the results from the control samples, we assessed the potential of the assays to detect previously infected animals in field situations. The samples were investigated using IDEXX Schmallenberg computer virus Antibody Test Kit, ID Screen Schmallenberg computer virus Competition Multi-species ELISA and Serum Neutralisation Test (SNT). Analysis of control samples revealed that SNT was the most suitable test, which was therefore used to calculate concordance and test overall performance for the two other ELISA assessments. To evaluate whether different assay performances had an impact under field conditions, sheep samples from two different contexts were tested: the emergence of AZ5104 SBV in Ireland and the re-emergence of SBV in Belgium. Comparing the results obtained from different assays to the non-reference standard assay SNT, we showed considerable differences in estimates of their sensitivity to detect SBV antibodies and to measure seroprevalence of the sheep flocks. Finally, a calculation of the number of randomly selected animals that needs to be screened from a finite flock, showed that SNT and ID.Vet are the most suitable to detect an introduction of the disease in low seroprevalence situations. The IDEXX ELISA test was only able to detect SBV antibodies in a higher seroprevalence context, which is not optimal for monitoring freedom of disease and surveillance studies. Introduction Schmallenberg computer virus (SBV) was first recognized in Germany in November 2011 [1]. It affects domestic and wild ruminants, in which it can cause abortions, stillbirths, or severe congenital malformations depending on the stage of embryological development of the offspring [2]. The AZ5104 ability of the computer virus to cross the placental barrier, and the effect around the adult animals and export restrictions, led to significant economic losses in European ruminant livestock from November 2011 to spring 2013 [3, 4, 5]. Flying insects of the spp. have been identified as vectors that play a key role in the spread of SBV [6, 7]. Since its discovery, evidence of SBV contamination in livestock has been found Rabbit Polyclonal to SNX3 throughout Europe. A number of studies in 2016 showed a reoccurrence of SBV infections around the continent, leading to the conclusion that this computer virus became endemic. The computer virus arrived in Ireland in 2012, where the first case of SBV was diagnosed in October 2012 [8] and its effects were very obvious in the southeast of Ireland [9]. In the 2013 lambing season in the East Wicklow area, reported losses AZ5104 were significant (up to 10% of affected lambs) and the typical deformed foetuses were observed, as well as some abortions. SBV spread rapidly across Europe, and Belgium has been identified as one of the first and most affected countries [10]. After initial SBV emergence in April 2011, massive distributing of viral contamination occurred. The last case of SBV contamination in Belgium was confirmed by PCR on an aborted foetus in March 2013 [11, 12]. Three years after the last reported outbreak of SBV, in April 2016, an abortion occurred in a two-year-old cow that previously had not been vaccinated, showing a new re-emergence of the computer virus in AZ5104 Belgium [13]. Correctly detecting emerging and re-emerging diseases such as SBV requires a reliable test that produces stable and consistent results. Therefore, the objectives of this study were to measure and compare the diagnostic overall performance including specificity and sensitivity of three assessments used in SBV antibody detection. In order to do so, sheep reference samples of known status were submitted to three assays: IDEXX Schmallenberg computer virus Antibody Test Kit (IDEXX), ID Screen Schmallenberg computer virus Competition Multi-species ELISA (ID.Vet) and Serum Neutralisation Test (SNT). In addition, diagnostic performance steps, including Youdens index (J) and Cohens kappa () were calculated based on reference samples. After obtaining results from the control sheep samples two questions were raised. How would these assays perform in the field conditions? Moreover, are there apparent differences in their ability to detect.