M. Swanenburg’s research while affiliated with Wageningen University & Research and other places

Safeguarding global health is a moving target, with changes in climate and human activity raising new threats to public health, animal health and animal welfare. Decision support in the context of health management requires tools capable of making sense of large volumes of complex and multidisciplinary evidence. A One Health living risk assessment tool, L'ORA, was developed to assess the incursion risk for zoonotic and animal diseases using a One Health approach and allowing for automatic updates of the risk assessment. L'ORA estimates the incursion risk as the resultant of four steps: 1) Disease occurrence in source areas based on the distribution of diseases worldwide; 2) Rate of incursion based on the individuals or products moved from source areas to target areas and their probability of infection or contamination and contact with susceptible hosts in target areas; 3) Extent of disease spread in target areas, considering both domestic and wild host populations, vectors if the disease is vector‐borne, and humans if the disease is zoonotic; and 4) Impact of the disease outbreak and concurrent control measures on public health, animal health and animal welfare, accounting for economic, societal, and environmental impacts. L'ORA is a decision support tool that was built as a generic tool comparing the relative risks of multiple diseases across multiple target areas. L'ORA monthly evaluates the incursion risk for each NUTS2 region in the European Union. Results can be used to identify areas of greater risk for each of the diseases to inform risk managers on where to focus attention and resources, and to inform, e.g., risk‐based surveillance.

Background: In the Netherlands, living in proximity to goat farms has been consistently associated with an increased incidence of community-acquired pneumonia (CAP). The cause remains largely unknown though airborne microbial agents could play a role. Objective: The aim of this study is to explore micro-organisms present in goats that can cause human pneumonia. Methods: An extensive literature review was conducted to identify all micro-organisms detected in goats that are associated with human pneumonia. Additionally, the identified micro-organisms were prioritized using a self-developed scoring system and expert opinion. Results: Through extensive literature review, 4309 references describing 302 different micro-organisms in goats or on goat farms were identified. Additional searches and reviews for human respiratory disease caused by each of these micro-organisms yielded a final list of 76 bacteria, 7 viruses, 7 fungi, and 6 protozoa. They were assigned scores based on pneumonia type, diagnosis of respiratory disease, patient immune status, and evidence strength. Based on these scores, the most likely potential causal micro-organisms included Moraxella spp. Chlamydia psittaci, Staphylococcus aureus, and Streptococcus pneumoniae. Subsequently, the list of micro-organisms was reviewed by external experts on their perceived likelihood of the organism causing this CAP. Conclusion: Results of this literature study can give insight into the possible causes of pneumonia. Nonetheless, no unambiguous conclusion on the actual cause of the increased CAP risk around goat farms can be drawn solely based on these results.

Background The parasite Toxoplasma gondii (T. gondii) causes a substantial human disease burden worldwide. Ingesting improperly cooked pork containing T. gondii is considered one of the major sources of human infection in Europe and North America. Consequently, control of T. gondii infections in pigs is warranted. The European Food Safety Authority advised to perform serological monitoring of pigs and to conduct farm audits for the presence of risk factors. Serological monitoring was implemented in several Dutch slaughterhouses, one to six blood samples (a total of 5134 samples) were taken from each delivery of finishing pigs and samples were tested for the presence of anti- T. gondii antibodies. Using these test results, a cross-sectional study was initiated to assess the association between the within-herd T. gondii seroprevalence and the presence of risk factors for T. gondii infections at 69 conventional finishing pig farms in the Netherlands. Results A multivariable model showed significant ( P ≤ 0.05) association with twelve potential risk factors: type of farm, presence of dogs, presence of ruminants, use of boots, use of shower and farm clothing, mode of rodent control, bedding accessibility for rodents, presence of cats, type of drinking water, heating of the feed, use of goat whey and shielding of birds. Conclusions Serological monitoring of finishing pigs for T. gondii in slaughterhouses can be used to identify the presence of T. gondii risk factors on Dutch conventional finishing pig farms and seems a valuable tool to guide and monitor the control of T. gondii in pork production.

Increasing globalization and international trade contribute to rapid expansion of animal and human diseases. Hence, preparedness is warranted to prevent outbreaks of emerging and re-emerging diseases or detect outbreaks in an early stage. We developed a rapid risk assessment tool (RRAT) to inform risk managers on the incursion risk of multiple livestock diseases, about the main sources for incursion and the change of risk over time. RRAT was built as a relational database to link data on disease outbreaks worldwide, on introduction routes and on disease-specific parameters. The tool was parameterized to assess the incursion risk of 10 livestock diseases for the Netherlands by three introduction routes: legal trade in live animals, legal trade of animal products, and animal products illegally carried by air travelers. RRAT calculates a semi-quantitative risk score for the incursion risk of each disease, the results of which allow for prioritization. Results based on the years 2016-2018 indicated that the legal introduction routes had the highest incursion risk for bovine tuberculosis, whereas the illegal route posed the highest risk for classical swine fever. The overall incursion risk via the illegal route was lower than via the legal routes. The incursion risk of African swine fever increased over the period considered, whereas the risk of equine infectious anemia decreased. The variation in the incursion risk over time illustrates the need to update the risk estimates on a regular basis. RRAT has been designed such that the risk assessment can be automatically updated when new data becomes available. For diseases with high-risk scores, model results can be analyzed in more detail to see which countries and trade flows contribute most to the risk, the results of which can be used to design risk-based surveillance. RRAT thus provides a multitude of information to evaluate the incursion risk of livestock diseases at different levels of detail. To give risk managers access to all results of RRAT, an online visualization tool was built.

In the veal industry in The Netherlands, each year around 1.2 million “white” veal calves are produced on around 1,100 farms. Bovine respiratory disease (BRD) causes serious health issues in these calves, also resulting in high usage of antimicrobials. To reduce antimicrobial usage, a more targeted treatment regime is needed, for which it is necessary to identify the causative agent. This study aimed at determining associations between pathogens and clinical disease, between prevalence of pathogens and BRD outbreaks, and BRD and performance. A cohort study was conducted involving ten veal farms, in which calf respiratory health was evaluated for the first 12 weeks. Whenever there was an outbreak of BRD, as determined by the farm veterinary surgeon, samples were taken from diseased and control calves through broncho-alveolar lavage. From these samples a broad spectrum of micro-organisms were isolated. Performance data were also collected. A total of 23 outbreaks happened during the 12 week study period, mostly in the first six weeks. BRD associated pathogens found were: BHV1, BPI3V, BRSV, BVDV, Pasteurella multocida, Mannheimia haemolytica, Trueperella pyogenes, Histophilus somni, Mycoplasma bovis, Mycoplasma bovirhinis and Mycoplasma dispar. For most BRD associated pathogens, there was no clear association between presence or prevalence of the micro-organisms and clinical issues. Only T. pyogenes (7.4% in healthy, 14.6% in diseased calves, p 0.013), M. bovis (37.6% and 63.2% respectively, p 0.001) and BVDV (9.9% and 16.9% respectively, p 0.03) were found more often in diseased animals. BPI3V was found in a few early outbreaks, which might suggest involvement in early outbreaks. It appears to be difficult to associate specific pathogens to outbreaks at the species level. BRD is the major reason for treatment with antimicrobials. More specific knowledge about the association between pathogens and health/disease could help to reduce antimicrobial use.

Background The parasite Toxoplasma gondii (T. gondii) is recognized worldwide as a pathogen causing a substantial human disease burden. Ingesting improperly cooked meat containing T. gondii is considered one of the major sources of human infection in Europe and North America. Consequently, control of T. gondii infections in pigs is warranted. The European Food Safety Authority (EFSA) advised to perform serological testing of pigs and farm audits for the presence of risk factors. Serological monitoring was implemented in several Dutch slaughterhouses. Blood samples from all deliveries of finishing pigs to the slaughterhouses were tested for the presence of anti-T. gondii antibodies. Using these test results, a case-control study was initiated to assess the association between the within-herd T. gondii seroprevalence and the presence of risk factors for T. gondii infections in 69 conventional finishing pig herds in the Netherlands. Results In a multivariable model twelve potential risk factors were significantly (P ≤ 0.05) associated with the level of seropositive T. gondii blood serum samples. Conclusions Serological screening of finishing pigs in the slaughterhouse for T. gondii can be used to identify presence of T. gondii risk factors on Dutch conventional finishing pig farms. The use of serological screening seems therefore a valuable tool to guide and monitor the control of T. gondii in pork production.

Early detection of emerging carbapenem-resistant Enterobacteriaceae (CPE) in food-producing animals is essential to control the spread of CPE. We assessed the risk of CPE introduction from imported livestock, livestock feed, companion animals, hospital patients, and returning travelers into livestock farms in The Netherlands, including (1) broiler, (2) broiler breeder, (3) fattening pig, (4) breeding pig, (5) farrow-to-finish pig, and (6) veal calf farms. The expected annual number of introductions was calculated from the number of farms exposed to each CPE source and the probability that at least one animal in an exposed farm is colonized. The total number of farms with CPE colonization was estimated to be the highest for fattening pig farms, whereas the probability of introduction for an individual farm was the highest for broiler farms. Livestock feed and imported livestock are the most likely sources of CPE introduction into Dutch livestock farms. Sensitivity analysis indicated that the number of fattening pig farms determined the number of high introductions in fattening pigs from feed, and that uncertainty on CPE prevalence impacted the absolute risk estimate for all farm types. The results of this study can be used to inform risk-based surveillance for CPE in livestock farms.

In 2014, EFSA received a mandate from the European Commission (EC) to assess the risk and consequences of introduction of new vector-borne diseases (VBDs), and to determine if further measures were needed. To support the work, a comprehensive and systematic extraction of data from the literature was conducted, covering 36 VBDs in 18 host mammalian species. Regular updates of this corpus of scientific evidence are needed to support risk assessments. The foundation set by the previous rounds of literature review for VBDs can be reused to provide efficient and reliable collection of scientific evidence to support EFSA needs in various areas of knowledge. EFSA has been requested to provide support to the EC via scientific opinions that would form the basis for the production of amending and implementing acts supporting Regulation 2016/429 (of the European Parliament and of the Council of 9 March 2016 on transmissible animal diseases and amending and repealing certain acts in the area of animal health – the “Animal Health Law”), which lays down rules for the prevention and control of animal diseases which are transmissible to animals or to humans. To support EFSA in keeping the available VBD knowledge as an up-to-date source of information for risk assessors, and in providing scientific opinions in matters related to Regulation 2016/429, the methodology for literature review has been further consolidated in seven specific areas of knowledge: experimental infections, pathogen survival, diagnostic tests performance, vaccines, preventive and curative treatments, vector treatments and geographical distribution. This document details the review protocol to update the available knowledge about the 36 VBDs within those seven areas since the last systematic literature reviews were carried out in 2017; as well as extend them to the terrestrial animals category A diseases in the “Animal Health Law”.