Gertraud Schüpbach-Regula

Expert Opinion on the Perceived Effectiveness and Importance of On-Farm Biosecurity Measures for Cattle and Swine Farms in Switzerland.

Biosecurity is crucial for safeguarding livestock from infectious diseases. Despite the plethora of biosecurity recommendations, published scientific evidence on the effectiveness of individual biosecurity measures is limited. The objective of this study was to assess the perception of Swiss experts about the effectiveness and importance of individual on-farm biosecurity measures for cattle and swine farms (31 and 30 measures, respectively). Using a modified Delphi method, 16 Swiss livestock disease specialists (8 for each species) were interviewed. The experts were asked to rank biosecurity measures that were written on cards, by allocating a score from 0 (lowest) to 5 (highest). Experts ranked biosecurity measures based on their importance related to Swiss legislation, feasibility, as well as the effort required for implementation and the benefit of each biosecurity measure. The experts also ranked biosecurity measures based on their effectiveness in preventing an infectious agent from entering and spreading on a farm, solely based on transmission characteristics of specific pathogens. The pathogens considered by cattle experts were those causing Bluetongue (BT), Bovine Viral Diarrhea (BVD), Foot and Mouth Disease (FMD) and Infectious Bovine Rhinotracheitis (IBR). Swine experts expressed their opinion on the pathogens causing African Swine Fever (ASF), Enzootic Pneumonia (EP), Porcine Reproductive and Respiratory Syndrome (PRRS), as well as FMD. For cattle farms, biosecurity measures that improve disease awareness of farmers were ranked as both most important and most effective. For swine farms, the most important and effective measures identified were those related to animal movements. Among all single measures evaluated, education of farmers was perceived by the experts to be the most important and effective for protecting both Swiss cattle and swine farms from disease. The findings of this study provide an important basis for recommendation to farmers and policy makers.

Coxiella burnetii Infections in Small Ruminants and Humans in Switzerland

&NA; The recent Q fever epidemic in the Netherlands raised concerns about the potential risk of outbreaks in other European countries. In Switzerland, the prevalence of Q fever in animals and humans has not been studied in recent years. In this study, we describe the current situation with respect to Coxiella (C.) burnetii infections in small ruminants and humans in Switzerland, as a basis for future epidemiological investigations and public health risk assessments. Specific objectives of this cross‐sectional study were to (i) estimate the seroprevalence of C. burnetii in sheep and goats, (ii) quantify the amount of bacteria shed during abortion and (iii) analyse temporal trends in human C. burnetii infections. The seroprevalence of C. burnetii in small ruminants was determined by commercial ELISA from a representative sample of 100 sheep flocks and 72 goat herds. Herd‐level seroprevalence was 5.0% (95% CI: 1.6–11.3) for sheep and 11.1% (95% CI: 4.9–20.7) for goats. Animal‐level seroprevalence was 1.8% (95% CI: 0.8–3.4) for sheep and 3.4% (95% CI: 1.7–6) for goats. The quantification of C. burnetii in 97 ovine and caprine abortion samples by real‐time PCR indicated shedding of >104 bacteria/g in 13.4% of all samples tested. To our knowledge, this is the first study reporting C. burnetii quantities in a large number of small ruminant abortion samples. Annual human Q fever serology data were provided by five major Swiss laboratories. Overall, seroprevalence in humans ranged between 1.7% and 3.5% from 2007 to 2011, and no temporal trends were observed. Interestingly, the two laboratories with significantly higher seroprevalences are located in the regions with the largest goat populations as well as, for one laboratory, with the highest livestock density in Switzerland. However, a direct link between animal and human infection data could not be established in this study.

A case-control study to estimate the effects of acute clinical infection with the Schmallenberg virus on milk yield, fertility and veterinary costs in Swiss dairy herds.

Schmallenberg virus (SBV) was first detected in Switzerland in July 2012 and many Swiss dairy farmers reported acute clinical signs in dairy cattle during the spread of the virus until December 2012. The objectives of the present study were to investigate the effects of an acute infection with SBV on milk yield, fertility and veterinary costs in dairy farms with clinical signs of SBV infection (case farms), and to compare those farms to a matched control group of dairy farms in which cattle did not show clinical signs of SBV infection. Herd size was significantly (p<0.001) larger in case farms (33 cows, n=77) than in control farms (25 cows, n=84). Within case herds, 14.8% (median) of the cows showed acute clinical signs. Managers from case farms indicated to have observed a higher abortion rate during the year with SBV (6.5%) than in the previous year (3.7%). Analysis of fertility parameters based on veterinary bills and data from the breeding associations showed no significant differences between case and control farms. The general veterinary costs per cow from July to December 2012 were significantly higher (p=0.02) in case (CHF 19.80; EUR 16.50) than in control farms (CHF 15.90; EUR 13.25). No differences in milk yield were found between groups, but there was a significant decrease in milk production in case farms in the second half year in 2012 compared to the same period in 2011 (p<0.001) and 2013 (p=0.009). The average daily milk yield per cow (both groups together) was +0.73kg higher (p=0.03) in the second half year 2011 and +0.52kg (p=0.12) in the second half year 2013 compared to the same half year 2012. Fifty-seven percent of the cows with acute clinical signs (n=461) were treated by a veterinarian. The average calculated loss after SBV infection for a standardized farm was CHF 1606 (EUR 1338), which can be considered as low at the national level, but the losses were subject to great fluctuations between farms, so that individual farms could have very high losses (>CHF 10,000, EUR 8333).

Economic evaluation of the eradication program for bovine viral diarrhea in the Swiss dairy sector

Since 2008, the Swiss veterinary service has been running a mandatory eradication program for Bovine Viral Diarrhea (BVD) that is focused on detecting and eliminating persistently infected (PI) animals. Detection was initially based on antigen testing from ear tag samples of the entire cattle population, followed by antigen testing of all newborn calves until 2012. Since then, bulk milk serology (dairy herds) and blood sample serology (beef herds) have been used for the surveillance of disease-free herds. From 2008 to 2012, the proportion of newborn PI calves decreased from 1.4% to less than 0.02%. However, this success was associated with substantial expenditures. The aim of this study was to conduct an economic evaluation of the BVD eradication program in the Swiss dairy sector. The situation before the start of the program (herd-level prevalence: 20%) served as a baseline scenario. Production models for three dairy farm types were used to estimate gross margins as well as net production losses and expenditures caused by BVD. The total economic benefit was estimated as the difference in disease costs between the baseline scenario and the implemented eradication program and was compared to the total eradication costs in a benefit-cost analysis. Data on the impact of BVD virus (BVDV) infection on animal health, fertility and production parameters were obtained empirically in a retrospective epidemiological case-control study in Swiss dairy herds and complemented by literature. Economic and additional production parameters were based on benchmarking data and published agricultural statistics. The eradication costs comprised the cumulative expenses for sampling and diagnostics. The economic model consisted of a stochastic simulation in @Risk for Excel with 20,000 iterations and was conducted for a time period of 14 years (2008-2021). The estimated annual financial losses in BVDV infected herds were CHF 85-89 per dairy cow and CHF 1337-2535 for an average farm, depending on the production type. The median net present value (NPV) was estimated at CHF 44.9 million (90% central range: CHF 13.4 million-69.4 million) and the break-even point to have been reached in 2015. Overall, the outcomes demonstrate that the Swiss BVD eradication program results in a net benefit for the dairy sector. These findings are relevant for planning similar BVD control programs in other countries.

Comparison of Antimicrobial Consumption Patterns in the Swiss and Danish Cattle and Swine Production (2007-2013).

Veterinary antimicrobial consumption patterns vary considerably across Europe. These differences are not only limited to the total amount consumed but are also observed with regards to the relative proportion of the various antimicrobial classes used. Currently, most of the data on veterinary antimicrobials are reported at sales level without any information on the consumption by different animal species. This hinders a proper comparison of antimicrobial consumption at the species level between countries. However, it is imperative to improve our understanding on antimicrobial usage patterns at the species level, as well as on the drivers contributing to those differences. This will allow for development of tailored interventions with the lowest possible risk for human health, while ensuring effective treatment of diseased livestock. An important step to attain such an objective is to perform detailed comparisons of the antimicrobial consumption in each species between countries. We compared antimicrobial consumption estimates for cattle and pigs in Switzerland and Denmark, in order to distinguish species-specific patterns and trends in consumption from 2007 to 2013. Swiss data were obtained from a previous study that assessed methodologies to stratify antimicrobial sales per species; Danish antimicrobial consumption estimates were assembled from Danish Integrated Antimicrobial Resistance Monitoring and Research Programme reports. A decrease in antimicrobial consumption in milligrams per kilogram of biomass was observed for both countries (4.5% in Denmark and 34.7% in Switzerland) when comparing 2013 to 2007. For pigs and cattle, the overall consumption per kilogram of biomass of most antimicrobial classes was higher in Switzerland than in Denmark. Large variations in the relative consumption of different antimicrobial classes were also evident. Sulfonamides/trimethoprim and tetracyclines were consumed in a higher proportion in Switzerland than in Denmark, whereas the relative consumption of penicillins was higher in Denmark. The differences observed in veterinary antimicrobial consumption are not solely related to animal demographic characteristics in these two countries. Other factors, such as the level of biosecurity and farming practices, veterinarians and farmers’ education, or governmental/industry programs put in place might also partly explain these variations. These differences should be taken into account when aiming to implement targeted interventions to reduce antimicrobial consumption.

Pooling of interdigital swab samples for PCR detection of virulent Dichelobacter nodosus.

Virulent ovine foot rot is a contagious foot disease. Given the development and validation of a real-time PCR to detect Dichelobacter nodosus isolates that contain the virulence-associated protease genes aprV2 and aprB2, the diagnosis of foot rot has made considerable progress. We evaluated pooling methods to reduce the number of samples during a foot rot control program. Samples of individual feet were compared to a 4-feet sample of the same sheep. All further analyses based on 4-feet samples (pools-of-5 and pools-of-10 4-feet samples) were compared to samples of individual sheep, and a risk-based herd sampling was evaluated and compared to the whole flock. The sensitivity and specificity of the 4-feet samples for detection of aprV2-positive strains was 93.8% (CI: 87.6–97.5%) and 98.3% (CI: 96.5–99.3%), respectively. The sensitivity and specificity of the pools-of-10 was 86.7% (CI: 78.4–92.7%) and 100.0% (CI: 97.4–100%), respectively. Pools-of-5 were not significantly more sensitive than pools-of-10. The pooling of 4 individual foot samples into one 4-feet sample is an adequate method to reduce the number of samples of individual sheep. The sensitivity of pools-of-5 and pools-of-10 is too imprecise for a control program. Risk-based sampling allowed for a substantial reduction of samples to be tested, had a sensitivity of 95.8% (CI: 78.9–99.9%) and specificity of 100.0% (CI: 88.1–100.0%) when determining the foot rot flock status, and represents an adequate methodology to predict within-flock freedom from infection.

A matched case-control study comparing udder health, production and fertility parameters in dairy farms before and after the eradication of Bovine Virus Diarrhoea in Switzerland

An obligatory eradication programme for Bovine Virus Diarrhoea (BVD) was implemented in Switzerland in 2008. Between 2008 and 2012, all bovines were tested for antigen or antibodies against BVDV. By the year 2012, eradication was completed in the majority of farms. A decrease of the prevalence of persistently infected (PI) newborn calves was observed from 1.4% in 2008 to <0.02% in 2012. The objective of the present study was to assess the effects of BVD eradication on different parameters of animal health, production and fertility in Swiss dairy herds which had completed the eradication programme. A matched case-control study was carried out using data from two periods, before (Period 1) and after (Period 2) the active phase of eradication. Case farms had at least two PI animals detected before or during the eradication; controls were BVD-free and matched for region, herd size and use of alpine pasture. A total of 110 farmers (55 pairs) were recruited. During a phone interview, a questionnaire about farm characteristics, animal health and appreciation of the BVD eradication programme was filled in. Breeding data and milk test day records were also analyzed. Parameters were first compared between (i) case and control herds before eradication, and (ii) Period 1 and Period 2 for case herds only. Milk yield (MY), bulk milk somatic cell count (BMSCC), prevalence of subclinical mastitis (SCM), and non-return rate (NRR) showed a p-value<0.25 in at least one of the univariable comparisons and were thus further analyzed with a multilevel mixed-effects model to account for repeated measures over time. In order to assess whether changes in health status over time were due to BVD eradication, an interaction variable between period and group (case-control) was created (IA). Except for MY, the IA was significant for all parameters modelled. Despite an overall p-value of 0.27, case herds tended to have a higher MY after eradication (β=0.53, p=0.050). For BMSCC and SCM, case herds had higher values than controls in both periods; udder health was significantly improved in control herds and it remained stable in case herds, with a slight decrease of BMSCC (β=-0.19, p=0.010). Finally, among fertility parameters, NRR showed a general improvement but it was significant only in control herds (β=0.29, p=0.019). Even though the effects of the eradication programme measured in this study were less pronounced than expected, 73% of the participants of this study had a positive attitude towards the campaign.

Epidemiological and Economic Evaluation of Alternative On-Farm Management Scenarios for Ovine Footrot in Switzerland

Footrot is a multifactorial infectious disease mostly affecting sheep, caused by the bacteria Dichelobacter nodosus. It causes painful feet lesions resulting in animal welfare issues, weight loss, and reduced wool production, which leads to a considerable economic burden in animal production. In Switzerland, the disease is endemic and mandatory coordinated control programs exist only in some parts of the country. This study aimed to compare two nationwide control strategies and a no intervention scenario with the current situation, and to quantify their net economic effect. This was done by sequential application of a maximum entropy model (MEM), epidemiological simulation, and calculation of net economic effect using the net present value method. Building upon data from a questionnaire, the MEM revealed a nationwide footrot prevalence of 40.2%. Regional prevalence values were used as inputs for the epidemiological model. Under the application of the nationwide coordinated control program without (scenario B) and with (scenario C) improved diagnostics [polymerase chain reaction (PCR) test], the Swiss-wide prevalence decreased within 10 years to 14 and 5%, respectively. Contrary, an increase to 48% prevalence was observed when terminating the current control strategies (scenario D). Management costs included labor and material costs. Management benefits included reduction of fattening time and improved animal welfare, which is valued by Swiss consumers and therefore reduces societal costs. The net economic effect of the alternative scenarios B and C was positive, the one of scenario D was negative and over a period of 17 years quantified at CHF 422.3, 538.3, and −172.3 million (1 CHF = 1.040 US

Antimicrobial Usage and -Resistance in Livestock: Where Should We Focus?

), respectively. This implies that a systematic Swiss-wide management program under the application of the PCR diagnostic test is the most recommendable strategy for a cost-effective control of footrot in Switzerland.

[Experiences with pain control during piglet castration in Switzerland Part 1: Inhalation anesthesia].

Antimicrobials represent one of humanity’s medical revolutions enabling us to treat both human and veterinary bacterial infections. It is, therefore, of utmost importance to preserve their effectiveness. However, during the last decades, the continuing rapid development of antimicrobial resistance (AMR) has emerged as a major global public health concern (1). Resistant bacteria may hamper the treatment of infections resulting in prolonged illness, disability, and death (2). In veterinary medicine, antimicrobials play a crucial role in the maintenance of animal health, animal welfare, and food-safety (3). However, a not yet quantifiable share of the burden of resistance for public health is attributable to the use of antimicrobials in livestock production (4–6). Farm animals are exposed to considerable quantities of antimicrobials (7) and can act as an important reservoir of AMR genes, which could be transmitted to humans through the food chain, direct animal contact and the environment. Use of antimicrobials in agriculture also includes those defined by the World Health Organization (WHO) as “critically important” for human medicine (8). Resistance against these substances can limit dramatically the treatment options against serious human bacterial diseases. Notorious examples include the vancomycin-resistant enterococci (VRE), the extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae and the recently detected plasmid-mediated colistin resistance (mcr-1 gene) in livestock, food, and humans in China (9–11). Resistant bacteria can be introduced into the environment through several ways, such as the land application of livestock manure as fertilizer (12). The globally rising aquaculture sector, which is characterized by extensive use of antimicrobials, represents another important source of resistant bacteria that can find their way into the environment (13). Our understanding on the epidemiology of AMR in livestock production is also hampered by the lack of comprehensive antimicrobial usage (AMU) data in the majority of countries. Furthermore, AMR development and spread is driven by human behavior, from the prescription of antimicrobials to infection prevention and control. Understanding these factors is a major step toward fighting against AMR. The complex epidemiology of AMR emphasizes the need for highly interdisciplinary research approaches, comprising humans, animals, and the wider environment. In line with the WHO global action plan on AMR (14), it is the authors’ opinion that research should be prioritized toward (a) understanding the social/behavioral drivers of AMU and AMR, (b) establishing or improving systems to monitor AMU, and (c) encouraging a holistic approach through the One-Health concept when addressing the phenomenon and risk of AMR.