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A random effect meta-analysis was performed to estimate the worldwide pooled bovine viral diarrhoea virus (BVDV) prevalences of persistently infected (PI), viraemic (VI) and antibody-positive (AB) animals and herds. The meta-analysis covered 325 studies in 73 countries that determined the presence or absence of BVDV infections in cattle from 1961 to 2016. In total, 6.5 million animals and 310,548 herds were tested for BVDV infections in the global cattle population. The worldwide pooled PI prevalences at animal level ranged from low (≤0.8% Europe, North America, Australia), medium (>0.8% to 1.6% East Asia) to high (>1.6% West Asia). The PI and AB prevalences in Europe decreased over time, while BVDV prevalence increased in North America. The highest mean pooled PI prevalences at animal level were identified in countries that had failed to implement any BVDV control and/or eradication programmes (including vaccination). Our analysis emphasizes the need for more standardised epidemiological studies to support decision-makers implementing animal health policies for non-globally-regulated animal diseases.

Bovine viral diarrhoea virus (BVDV) is an important infectious agent of cattle worldwide that affects herd productivity and reproduction. In this systematic review of the impact of BVDV, studies were analysed with a particular focus on the monetary implications and types of direct losses, the initial infection status of herds, production systems, time periods of assessment, calculation level, study types and whether or not country-specific assessments were published. A linear mixed model was applied to analyse factors that influence the level of monetary direct losses due to BVDV infection. The 44 studies included in this review covered 15 countries and assessed direct monetary losses due to BVDV incurred over the past 30 years. Direct losses between and within countries were largely heterogeneous with respect to the monetary level and types of direct losses, ranging from 0.50 to 687.80 US dollars (USD) per animal. Average direct losses per naïve dairy cow were USD24.85 higher than per beef cow. Country-specific assessments of direct losses due to BVDV were provided in 38/44 (86.4%) studies. Mortality, morbidity, premature culling, stillbirths, abortion, reinfection, country and study type had a significant influence on the monetary level of direct losses (r = 0.69). Countries recording direct losses were more likely to carry out voluntary or compulsory control and eradication programmes (odds ratio = 10.2; 95% confidence interval 1.7-81.9; P = 0.004).

Infection with bovine viral diarrhea virus (BVDV) results in major economic losses either directly through decreased productive performance in cattle herds or indirectly, such as through expenses for control programs. The aim of this systematic review was to review financial and/or economic assessment studies of prevention and/or mitigation activities of BVDV at national, regional and farm level worldwide. Once all predefined criteria had been met, 35 articles were included for this systematic review. Studies were analyzed with particular focus on the type of financially and/or economically-assessed prevention and/or mitigation activities. Due to the wide range of possible prevention and/or mitigation activities, these activities were grouped into five categories: i) control and/or eradication programs, ii) monitoring or surveillance, iii) prevention, iv) vaccination and v) individual culling, control and testing strategies. Additionally, the studies were analyzed according to economically-related variables such as efficiency, costs or benefits of prevention and/or mitigation activities, the applied financial and/or economic and statistical methods, the payers of prevention and/or mitigation activities, the assessed production systems, and the countries for which such evaluations are available. Financial and/or economic assessments performed in Europe were dominated by those from the United Kingdom, which assessed mostly vaccination strategies, and Norway which primarily carried out assessments in the area of control and eradication programs; whereas among non-European countries the United States carried out the majority of financial and/or economic assessments in the area of individual culling, control and testing. More than half of all studies provided an efficiency calculation of prevention and/or mitigation activities and demonstrated whether the inherent costs of implemented activities were or were not justified. The dairy sector was three times more likely to be assessed by the countries than beef production systems. In addition, the dairy sector was approximately eight times more likely to be assessed economically with respect to prevention and/or mitigation activities than calf and youngstock production systems. Furthermore, the private sector was identified as the primary payer of prevention and/or mitigation activities. This systematic review demonstrated a lack of studies relating to efficiency calculations, in particular at national and regional level, and the specific production systems. Thus, we confirmed the need for more well-designed studies in animal health economics in order to demonstrate that the implementation and inherent costs of BVDV prevention and/or mitigation activities are justified.

A project to establish an Austria-wide health-monitoring system for cattle was launched in 2006. Veterinary diagnostic data subject to documentation by law [Law on the Control of Veterinary Medicinal Products (Tierarzneimittelkontrollgesetz)] are standardized, validated, and recorded in a central database. This Austria-wide project is a collaboration among agricultural and veterinary organizations as well as universities, and is also supported by the Austrian government. In addition to providing information for herd management and preventive measures, further objectives of the project include estimating breeding values for health traits and monitoring the overall health status of Austria's cattle. To ensure a high level of participation from farmers and veterinarians, data security issues are extremely important. Valid data are the prerequisite for the efficient use of health records. The challenge hereby is to distinguish between farms with low frequencies of diseases and incomplete documentation and recording. Measures were undertaken to establish a routine monitoring system for direct health traits. A routine genetic evaluation for direct health traits as part of the joint breeding value estimation program between Germany and Austria was introduced for Fleckvieh in December 2010, based on diagnostic data from 5,428 farms with 147,764 Fleckvieh cows. In 2010 to 2011, the reporting of direct health traits as a compulsory part of performance recording and the breeding program was introduced as well. The overall challenge is the availability of sufficient valid direct health data for reliable breeding values. Practical experience gained in Austria in setting up a health registration system, focusing mainly on the availability of direct health data for breeding purposes with its successes and difficulties, is described.