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A Corrigendum onControl and Eradication Programs for Six Cattle Diseases in the Netherlands by Santman-Berends, I. M. G. A., Mars, M. H., Weber, M. F., van Duijn, L., Waldeck, H. W. F., Biesheuvel, M. M., van den Brink, K. M. J. A., Dijkstra, T., Hodnik, J. J., Strain, S. A. J., de Roo, A., Veldhuis, A. M. B., and van Schaik, G. (2021). Front. Vet. Sci. 8:670419. doi: 10.3389/fvets.2021.670419

Within the European Union, infectious cattle diseases are categorized in the Animal Health Law. No strict EU regulations exist for control, evidence of disease freedom, and surveillance of diseases listed other than categories A and B. Consequently, EU member states follow their own varying strategies for disease control. The aim of this study was to provide an overview of the control and eradication programs (CPs) for non-EU regulated cattle diseases in the Netherlands between 2009 and 2019 and to highlight characteristics specific to the Dutch situation. In the Netherlands, CPs are in place for six endemic cattle diseases: bovine viral diarrhea, infectious bovine rhinotracheitis, salmonellosis, paratuberculosis, leptospirosis, and neosporosis. These CPs have been tailored to the specific situation in the Netherlands: a country with a high cattle density, a high rate of animal movements, a strong dependence on export of dairy products, and a high-quality data-infrastructure. The latter specifically applies to the dairy sector, which is the leading cattle sector in the Netherlands. When a herd enters a CP, generally the within-herd prevalence of infection is estimated in an initial assessment. The outcome creates awareness of the infection status of a herd and also provides an indication of the costs and time to achieve the preferred herd status. Subsequently, the herd enrolls in the control phase of the CP to, if present, eliminate the infection from a herd and a surveillance phase to substantiate the free or low prevalence status over time. The high-quality data infrastructure that results in complete and centrally registered census data on cattle movements provides the opportunity to design CPs while minimizing administrative efforts for the farmer. In the CPs, mostly routinely collected samples are used for surveillance. Where possible, requests for proof of the herd status are sent automatically. Automated detection of risk factors for introduction of new animals originating from a herd without the preferred herd status i.e., free or unsuspected, is in place using centrally registered data. The presented overview may inspire countries that want to develop cost-effective CPs for endemic diseases that are not (yet) regulated at EU level.

In the Netherlands, the feasibility of a national control program for infectious bovine rhinotracheitis (IBR) is discussed. The aim of this program would be to achieve freedom from BoHV1 circulation (the causal agent of IBR), in the Dutch cattle population. When IBR would be eradicated, maintaining the free status is essential and insight in the probability of introduction of IBR through cattle imports is crucial. Values for input parameters such as the number of imports per country of origin, herd level prevalence and probability that a random imported animal per age category was either acutely or latently infected with IBR were quantified. A stochastic simulation model was built to predict the basic risk and the efficacy of four risk mitigating scenarios were evaluated. These scenarios involved testing prior to import, import restrictions and vaccination. The model output predicted that IBR infected animals are imported regularly. In an IBR free situation, 571 (5th and 95th percentile: 431-781) cattle herds will be newly infected. Latent infections account for most newly infected herds (77%). When the virus in the imported latently infected animal does not reactivate, subsequent impact of such infections remains limited. The model predicted that most of the herds infected by introduction of acutely infected animals would be veal herds. The scenario in which imports were only allowed from status 9 or 10 countries combined with testing cattle that originated from status 9 countries was most effective in reduction of the import risk to 70 herds per year. The scenario in which vaccination of calves was combined with testing of older cattle was estimated to reduce the number of newly infected herds to 82 per year. The stakeholders classified the latter scenario as most realistic because this scenario was deemed both feasible and rather effective. This study did not evaluate the impact of introduction of IBR in the cattle population, which might differ depending on the type of infection (acute vs. latent) and the herd type in which the virus is introduced. Moreover, when making the final decision about the optimal intervention, the economic perspective should also be taken into account. This study predicted that introduction of IBR will remain a risk for the Dutch cattle population after virus circulation is eliminated from the Netherlands. The import risk is reduced most in scenarios in which testing and vaccination are combined.