This Scientific Report identifies the potential entry pathways for 25 selected vector-borne diseases (VBDs) into currently free EU Member States. The diseases comprise 12 listed under the Animal Health Law (AHL) and 13 non-listed diseases, selected using predefined eligibility criteria. The report represents a preparatory step supporting subsequent EU-level risk assessments of disease introduction, spread and impact, with emphasis on pathway identification rather than risk estimation. Evidence was collected through structured narrative literature reviews, complemented by expert judgement. Entry pathways were classified as vector-related or non-vectorial. A conservative, inclusion-based approach was applied, whereby only pathways considered with high certainty to be epidemiologically irrelevant were excluded. For tick-borne pathogens, the only potential vector-related entry pathway is the movement of ticks attached to livestock, wildlife or pets. For sandfly-borne pathogens, entry may occur through local dispersal and gradual expansion of established vector populations. For Culicoides-borne pathogens, wind-borne dispersal of adult midges, including over long distances, is considered a potential entry pathway, while active flight and vehicle-associated transport are relevant only over short distances. For mosquito-borne pathogens, the introduction of adult mosquitoes via aircraft is considered a potential entry pathway for all pathogens addressed. For West Nile virus, additional potential pathways include active flight from neighbouring affected areas, expansion of mosquito populations and wind-assisted dispersal. For pathogens mechanically transmitted by biting flies (lumpy skin disease virus, Besnoitia besnoiti and equine infectious anaemia virus), vector-related entry pathways are limited to active movement and short-distance wind dispersal within areas where the pathogens are already present in the EU, with passive transport via land vehicles considered a plausible additional pathway. Non-vectorial pathways mainly involve the movement of live animals via livestock trade, companion animal movements or wildlife migration when infected hosts enter areas with competent vectors. Germinal products are considered only for pathogens with demonstrated vertical transmission, while products of animal origin are relevant for a limited subset of pathogens. Overall, the report provides a structured framework to support EU-level assessment of VBD introduction pathways.

Abstract This scientific report provides a structured overview of the main characteristics of 25 selected vector‐borne diseases (VBDs) of potential relevance for the EU, including 12 diseases listed under the Animal Health Law (AHL) and 13 non‐listed diseases. The objective is to compile and harmonise existing knowledge to support subsequent risk assessments, together with three complementary scientific reports on (1) vector competence and geographical distribution for the disease agents of arthropod species, (2) available surveillance and control measures for the VBDs and (3) potential pathways for introduction. Diseases were selected based on predefined eligibility criteria, including absence or uncertain status in at least half of EU Member States, the presence of competent vectors, susceptible domestic animal hosts and data availability. The report builds on EFSA's systematic literature review framework for Animal Disease Profiles, covering six knowledge areas: experimental infections studying infection dynamics and clinical manifestations in different hosts, pathogen survival and transmission modes, diagnostic test accuracy, vaccine efficacy, preventive and curative treatment efficacy and geographical distribution of the pathogens. Results are presented as standardised disease fact sheets, providing a harmonised and transparent evidence base to support EU‐level risk assessments. While this report will be updated on an annual basis, continuously updated information, including interactive maps and full reference data sets, are available through EFSA's online Disease Profiles platform.

A comprehensive synthesis of current evidence on surveillance, prevention and control measures for 25 selected vector-borne diseases (VBDs) affecting animals in the EU is presented here. The assessment integrates evidence from systematic literature reviews, modelling studies, field investigations and expert judgement. The aim is mapping the availability and effectiveness of risk mitigation measures (RMMs), including surveillance, movement restrictions, vaccination, culling, medicinal treatments, on-farm biosecurity and vector control. Of the 25 VBDs considered, 13 are listed under the EU Animal Health Law (AHL) and categorised according to disease control priorities, while 12 additional non-listed diseases were included based on vector presence and epidemiological relevance. Surveillance emerges as the most comprehensively documented mitigation category and is recognised as the cornerstone of VBD risk management. Evidence supports its critical role in early detection, situational awareness and timely response through integrated monitoring of hosts, vectors, pathogens and environmental drivers. Movement restrictions are supported by a moderate evidence base, primarily derived from modelling studies, indicating that they can reduce transmission under specific epidemiological conditions; however, their stand-alone effectiveness is difficult to quantify in real-world outbreaks. Vaccination shows high efficacy and effectiveness for several key VBDs, including African horse sickness virus, bluetongue virus, lumpy skin disease virus and Rift Valley fever virus, with substantial reductions in infection, morbidity and mortality. Evidence for culling is limited and highly disease-specific, and its effectiveness is generally contingent on the combination with other control measures. Medicinal treatments are limited to some groups of pathogens and demonstrate variable effectiveness, with emerging concerns regarding drug resistance. Biosecurity and vector control measures are supported by heterogeneous evidence, with chemical vector control showing robust entomological efficacy, but limited empirical data linking vector reduction to disease incidence. The report identifies key knowledge gaps and uncertainties across RMM categories and provides targeted recommendations for research to strengthen future VBD mitigation capacity in the EU.

This report addresses Term of Reference 1.2 by providing a comprehensive knowledge-mapping of arthropod vector species competent to transmit selected vector-borne diseases (VBDs) including VBDs listed under Regulation (EU) 2016/429 and Regulation (EU) 2020/687, as well as additional non-listed pathogens with potential epidemiological relevance. The objective was to update and consolidate evidence on biological vector competence, mechanical transmission and vector geographic distribution for 25 selected VBDs in support of subsequent EU-level risk-assessment activities. Biological vector competence was assessed through two systematic literature reviews (SLRs), one focusing on pathogen detection in field-collected arthropods and the other on laboratory infection and transmission studies, while mechanical transmission was evaluated through a narrative literature review using predefined hierarchical criteria to classify vector likelihood. Geographic distribution data were updated via a third dedicated living SLR feeding into the VectorNet mapping workflow. Evidence from all reviews was synthesised, and expert judgement was applied where necessary to address data gaps. Literature reviews were conducted at global level, whereas geographic distribution maps were provided for vector species occurring in the EU and neighbouring countries, where available. The SLRs identified arthropod species with a highly likely biological vector competence for eight pathogens, supported by convergent field and laboratory evidence, and potential biological vectors for a further 16 pathogens based on evidence from either field or laboratory studies; for all these pathogens, at least one relevant vector species occurs in the EU or neighbouring regions and EU-level distribution maps are available. For a limited number of pathogens (5), no eligible biological vectors occurring in the EU were identified and expert judgement was therefore applied to identify plausible vectors. For mechanical transmission, the narrative review identified three pathogens associated with highly likely and four pathogens with potential mechanical vectors occurring in the EU or neighbouring countries, while expert judgement was required for two pathogens. Although EU-level distribution maps are not available for mechanically transmitted vectors, their widespread occurrence means geographic distribution is not considered a limiting factor for risk assessment. Evidence gaps remain for several pathogen-vector associations and will be further considered in subsequent assessments.

Since its emergence in Georgia in 2007, the seasonal pattern of African swine fever virus (ASFV) genotype II outbreaks in European pig populations has been evident. It is hypothesized that summer-related farming practices, along with the increased activity and abundance of arthropod vectors during warmer months, contribute to the increased incidence of these outbreaks during this period. This study investigated the potential role of stable flies (Stomoxys calcitrans) and biting midges of the genus Culicoides as mechanical vectors of ASFV. In addition, the potential distribution and abundance of different species of Culicoides biting midges on pig farms was investigated. From August 2021 to August 2023, vector surveillance was conducted as part of a case–control study on 42 outbreak farms and 70 control farms across Romania, Lithuania, and Poland. Collected insect specimens were pooled and tested for ASFV DNA using real-time polymerase chain reaction (PCR). A total of 8604 biting midges of the genus Culicoides specimens and 742 S. calcitrans flies were collected, with ASF DNA detected in 27 out of 1219 insect pools. Positive pools were predominantly observed in Culicoides punctatus, C. newsteadi, and the Obsoletus complex, with most detections occurring in August. However, ASFV isolation was unsuccessful. Statistical analyses revealed no significant association between farm status (outbreak versus control) and ASFV DNA detection in pools of biting midges of the genus Culicoides, likely due to limited sample size. Additionally, two ASFV-positive S. calcitrans pools were identified, supporting their potential role as mechanical vehicles for ASFV. The findings highlight the affinity of C. punctatus, C. newsteadi, and the Obsoletus complex and S. calcitrans for pig farms – an aspect that was previously undocumented. This association may increase the likelihood of ASFV acquisition and dissemination by these species. Environmental factors, such as pig farm density and proximity to other hosts, likely influence this risk. These results emphasize the importance of vector control strategies, including insect netting, to mitigate ASFV transmission risks. Further research is needed to understand the dynamics of ASFV infection in arthropods. Notably, this study also reports the first identification of Culicoides riethi and Culicoides salinarius in Lithuania.

Since African swine fever virus (ASFV) genotype II reached Europe in 2007 and has widely spread, causing important economic losses to the pig production sector. To guide policy and management actions, robust quantitative evidence about possible explanatory variables associated with ASF in domestic pigs and Eurasian wild boar (Sus scrofa) is needed. To this aim, a systematic literature review of the scientific evidence available on variables analysed through quantitative methods investigating their possible association with ASF occurrence was carried out in 2021 and updated in 2024. Information on article metadata, study settings, and details of the analysed variables were extracted from the identified articles. The variables were structured in categories and subcategories, and their frequencies were evaluated, as well as the proportions of the studied variables that proved significant in each subcategory. The literature search retrieved 569 articles, resulting in 48 inclusions in the review after application of the selection criteria. The categories of variables most often significantly associated with the occurrence of ASF in domestic pigs were related to the ASF virus infection pressure in the area, socio-economic factors (mainly human population density and poverty), the pig farming system (pig or farm density and certain biosecurity practises), and wild boar habitats. For wild boars, these were also variables related to ASFV infection pressure in the area, wild boar habitats (mainly climatic conditions, vegetation, waterbodies), and socio-economic factors (especially human population and poverty-related variables). Despite the many studies of variables possibly associated with ASF occurrence, the review identified a gap in quantitative observational studies focusing on manageable variables, i.e., those related to specific biosecurity measures applied to pig farms and during hunting. To allow for a meta-analysis of the results, these studies should be performed according to standardised protocols using harmonised data collections.

Five epidemiological aspects of ASF were evaluated using literature reviews, field studies, questionnaires and mathematical models. First, a literature review and a case-control study in commercial pig farms emphasised the importance of biosecurity and farming practices, including the spread of manure around farms and the use of bedding material as risk factors, while the use of insect nets was a protective factor. Second, although wild boar density is a relevant known factor, the statistical and mechanistic models did not show a clear and consistent effect of wild boar density on ASF epidemiology in the selected scenarios. Other factors, such as vegetation, altitude, climate and barriers affecting population connectivity, also played a role on ASF epidemiology in wild boar. Third, knowledge on Ornithodoros erraticus competence, presence and surveillance was updated concluding that this species did not play any role in the current ASF epidemic in affected areas of the EU. Available scientific evidence suggests that stable flies and horse flies are exposed to ASFV in affected areas of the EU and have the capacity to introduce ASFV into farms and transmit it to pigs. However, there is uncertainty about whether this occurs, and if so, to what extent. Fourth, research and field experience from affected countries in the EU demonstrates that the use of fences, potentially used with existing road infrastructure, coupled with other control methods such as culling and carcass removal, can effectively reduce wild boar movements contributing to ASF management in wild boar. Fences can contribute to control ASF in both scenarios, focal introductions and wave-like spread. Fifth, the use of gonadotropin-releasing hormone (GnRH) vaccines as an immune contraceptive has the potential, as a complementary tool, to reduce and control wild boar populations. However, the development of an oral GnRH vaccine for wild boar still requires substantial additional work.

African swine fever (ASF) is a highly contagious and severe haemorrhagic disease of Suidae, with mortalities that approach 100 percent. Several studies suggested the potential implication of non-biting dipterans in the spread of ASFV in pig farms due to the identification of the ASFV DNA. However, to our knowledge, no study has evaluated the viral DNA load in non-biting dipterans collected in outbreak farms and no risk factors have been analysed. In this context, our study aimed to analyse the risk factors associated with the presence of non-biting dipterans collected from ASF outbreaks in relation to the presence and load of viral DNA. Backyard farms (BF), type A farms (TAF), and commercial farms (CF), were targeted for sampling in 2020. In 2021, no BF were sampled. Each farm was sampled only once. The identification of the collected flies to family, genus, or species level was performed based on morphological characteristics using specific keys and descriptions. Pools were made prior to DNA extraction. All extracted DNA was tested for the presence of the ASFV using a real-time PCR protocol. For this study, we considered every sample with a CT value of 40 as positive. The statistical analysis was performed using Epi Info 7 software (CDC, USA). All collected non-biting flies belonged to five families: Calliphoridae, Sarcophagidae, Fanniidae, Drosophilidae, and Muscidae. Of the 361 pools, 201 were positive for the presence of ASFV DNA. The obtained CT values of the positive samples ranged from 21.54 to 39.63, with a median value of 33.59 and a mean value of 33.56. Significantly lower CT values (corresponding to higher viral DNA load) were obtained in Sarcophagidae, with a mean value of 32.56; a significantly higher number of positive pools were noticed in August, mean value = 33.12. Our study brings compelling evidence of the presence of the most common synanthropic flies near domestic pig farms carrying ASFV DNA, highlighting the importance of strengthening the biosecurity measures and protocols for prevention of the insect life cycle and distribution.

Background Arthropod vectors such as ticks, mosquitoes, sandflies and biting midges are of public and veterinary health significance because of the pathogens they can transmit. Understanding their distributions is a key means of assessing risk. VectorNet maps their distribution in the EU and surrounding areas. Aim We aim to describe the methodology underlying VectorNet maps, encourage standardisation and evaluate output. Method s: Vector distribution and surveillance activity data have been collected since 2010 from a combination of literature searches, field-survey data by entomologist volunteers via a network facilitated for each participating country and expert validation. Data were collated by VectorNet members and extensively validated during data entry and mapping processes. Results As of 2021, the VectorNet archive consisted of ca 475,000 records relating to > 330 species. Maps for 42 species are routinely produced online at subnational administrative unit resolution. On VectorNet maps, there are relatively few areas where surveillance has been recorded but there are no distribution data. Comparison with other continental databases, namely the Global Biodiversity Information Facility and VectorBase show that VectorNet has 5–10 times as many records overall, although three species are better represented in the other databases. In addition, VectorNet maps show where species are absent. VectorNet’s impact as assessed by citations (ca 60 per year) and web statistics (58,000 views) is substantial and its maps are widely used as reference material by professionals and the public. Conclusion VectorNet maps are the pre-eminent source of rigorously validated arthropod vector maps for Europe and its surrounding areas.

BACKGROUND AND OBJECTIVE:No autochthonous human cases of Japanese encephalitis (JE) have been reported to date in the European Union (EU). In this study, we assess the likelihood of Japanese encephalitis virus (JEV) introduction and transmission within the EU and propose outbreak response measures. RISK ASSESSMENT:Given the global geographical distribution of JEV, the probability of virus introduction into the EU is currently very low, with viremic bird migration being the most plausible pathway of introduction. However, this likelihood would significantly increase if the virus were to become established in the Middle East, Caucasus, Central Asia or Africa. Considering the environmental conditions that are expected to be conducive for virus circulation, there is a high likelihood of virus transmission within the EU after its introduction in environmentally suitable areas. The spread of the virus within the EU would likely occur through the movement of wild birds, pigs and mosquitoes. MITIGATION:To mitigate or potentially contain the emergence of JE in the EU, early detection of both human and animal cases will be crucial.

Vector or reservoir species of three diseases of crustaceans listed in the Animal Health Law were identified based on evidence generated through an extensive literature review, to support a possible updating of Regulation (EU) 2018/1882. Crustacean species on or in which Taura syndrome virus (TSV), Yellow head virus (YHV) or White spot syndrome virus (WSSV) were identified, in the field or during experiments, were classified as reservoir species with different levels of certainty depending on the diagnostic tests used. Where experimental evidence indicated transmission of the pathogen from a studied species to another known susceptible species, the studied species was classified as vector species. Although the quantification of the risk of spread of the pathogens by the vectors or reservoir species was not part of the terms of reference, such risks do exist for the vector species, since transmission from infected vector species to susceptible species was proven. Where evidence for transmission from infected crustaceans was not found, these were defined as reservoirs. Nonetheless, the risk of the spread of the pathogens from infected reservoir species cannot be excluded. Evidence identifying conditions that may prevent transmission by vectors during transport was collected from scientific literature. It was concluded that it is very likely to almost certain (90-100%) that WSSV, TSV and YHV will remain infective at any possible transport condition. Therefore, vector or reservoir species that may have been exposed to these pathogens in an affected area in the wild or aquaculture establishments or by water supply can possibly transmit WSSV, TSV and YHV.

Public and animal health authorities face many challenges in surveillance and control of vector-borne diseases. Those challenges are principally due to the multitude of interactions between vertebrate hosts, pathogens, and vectors in continuously changing environments. VectorNet, a joint project of the European Food Safety Authority (EFSA) and the European Centre for Disease Prevention and Control (ECDC) facilitates risk assessments of VBD threats through the collection, mapping and sharing of distribution data for ticks, mosquitoes, sand flies, and biting midges that are vectors of pathogens of importance to animal and/or human health in Europe. We describe the development and maintenance of this One Health network that celebrated its 10th anniversary in 2020 and the value of its most tangible outputs, the vector distribution maps, that are freely available online and its raw data on request. VectorNet encourages usage of these maps by health professionals and participation, sharing and usage of the raw data by the network and other experts in the science community. For the latter, a more complete technical description of the mapping procedure will be submitted elsewhere.

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”.

Abstract An update on the African swine fever (ASF) situation in the 10 affected Member States (MS) in the EU and in two neighbouring countries from the 1 September 2019 until the 31 August 2020 is provided. The dynamics of the proportions of PCR‐ and ELISA‐positive samples since the first ASF detection in the country were provided and seasonal patterns were investigated. The impact of the ASF epidemic on the annual numbers of hunted wild boar in each affected MS was investigated. To evaluate differences in the extent of spread of ASF in the wild boar populations, the number of notifications that could be classified as secondary cases to a single source was calculated for each affected MS and compared for the earliest and latest year of the epidemic in the country. To evaluate possible risk factors for the occurrence of ASFV in wild boar or domestic pigs, a literature review was performed. Risk factors for the occurrence of ASF in wild boar in Romanian hunting grounds in 2019 were identified with a generalised linear model. The probability to find at least one PCR‐confirmed ASF case in wild boar in a hunting ground in Romania was driven by environmental factors, wild boar abundance and the density of backyard pigs in the hunting ground area, while hunting‐related variables were not retained in the final model. Finally, measures implemented in white zones (ASF‐free zones that are geographically adjacent to an area where ASF is present in wild boar) to prevent further spread of ASF were analysed with a spatially, explicit stochastic individual‐based model. To be effective, the wild boar population in the white zone would need to be drastically reduced before ASF arrives at the zone and it must be wide enough. To achieve the necessary pre‐emptive culling targets of wild boar in the white zone, at the start of the establishment, the white zone should be placed sufficiently far from the affected area, considering the speed of the natural spread of the disease. This spread is faster in denser wild boar populations. After a focal ASF introduction, the white zone is always close to the infection hence pre‐emptive culling measures in the white zone must be completed in short term, i.e. in a few months.

Abstract The European Commission requested that EFSA provide study designs for the investigation of four research domains according to major gaps in knowledge identified by EFSA in a report published in 2019: (i) the patterns of seasonality of African Swine Fever (ASF) in wild boar and domestic pigs in the EU; (ii) the epidemiology of ASF in wild boar; (iii) survival of ASF virus (ASFV) in the environment and (iv) transmission of ASFV by vectors. In this Scientific Opinion, the fourth research domain on ASFV transmission by vectors is addressed. Eleven research objectives were proposed by the EFSA working group and broader ASF expert networks, such as ASF stop, ENETWILD, VectorNet, AHAW network and the AHAW Panel Experts. Of the 11 research objectives, six were prioritised based on the following set of criteria: (1) the impact on ASF management; (2) the feasibility or practicality to carry out the study; (3) the potential implementation of study results in practice; (4) a possible short time‐frame study (< 1 year); (5) the novelty of the study and (6) if it was a priority for risk managers. The prioritised research objectives were: (I) Studies on the potential vector fauna at the pig–wild boar interface and the feeding preference of blood‐feeding potential vectors in ASF‐affected areas; (II) Assessment of the efficacy of insect screens on indoor/outdoor pig holdings to prevent the entry of blood‐sucking vectors (i.e. Stomoxys) in ASF endemic areas; (III) Assess the role of mechanical vectors in the virus transmission in ASF‐affected areas; (IV) Distribution of the potential mechanical transmission vectors in ASF‐affected areas of the EU; (V) ASFV transmission by synanthropic birds; and (VI) Assessment on the presence/absence of the soft tick Ornithodoros erraticus in ASF‐affected areas in Europe. For each of the selected research objectives, a research protocol has been proposed considering the potential impact on ASF management and the period of 1 year for the research activities.

Abstract The European Commission requested that EFSA provide study designs for the investigation of four research domains according to major gaps in knowledge identified by EFSA in a report published in 2019: i) the patterns of seasonality of African Swine Fever (ASF) in wild boar and domestic pigs in the EU; ii) the epidemiology of ASF in wild boar; iii) survival of ASF virus (ASFV) in the environment and iv) transmission of ASFV by vectors. In this Scientific Opinion, the third research domain on ASFV survival is addressed. Nine research objectives were proposed by the working group and broader ASF expert networks, such as ASF stop, ENETWILD, VectorNet, AHAW network and the AHAW Panel Experts. Of the nine research objectives, only one was prioritised and elaborated into a general protocol/study design research proposal, pertaining ASFV survival in feed and bedding. To investigate the survival of ASFV in feed, bedding and roughage, laboratory survival studies are proposed. To investigate possible risk mitigation measures, proof‐of‐concept approaches should be investigated.

Abstract EFSA assessed the role of seropositive wild boar in African swine fever (ASF) persistence. Surveillance data from Estonia and Latvia investigated with a generalised equation method demonstrated a significantly slower decline in seroprevalence in adult animals compared with subadults. The seroprevalence in adults, taking more than 24 months to approach zero after the last detection of ASFV circulation, would be a poor indicator to demonstrate the absence of virus circulation. A narrative literature review updated the knowledge on the mortality rate, the duration of protective immunity and maternal antibodies and transmission parameters. In addition, parameters potentially leading to prolonged virus circulation (persistence) in wild boar populations were reviewed. A stochastic explicit model was used to evaluate the dynamics of virus prevalence, seroprevalence and the number of carcasses attributed to ASF. Secondly, the impact of four scenarios on the duration of ASF virus (ASFV) persistence was evaluated with the model, namely a: (1) prolonged, lifelong infectious period, (2) reduction in the case‐fatality rate and prolonged transient infectiousness; (3) change in duration of protective immunity and (4) change in the duration of protection from maternal antibodies. Only the lifelong infectious period scenario had an important prolonging effect on the persistence of ASF. Finally, the model tested the performance of different proposed surveillance strategies to provide evidence of the absence of virus circulation (Exit Strategy). A two‐phase approach (Screening Phase, Confirmation Phase) was suggested for the Exit Strategy. The accuracy of the Exit Strategy increases with increasing numbers of carcasses collected and tested. The inclusion of active surveillance based on hunting has limited impact on the performance of the Exit Strategy compared with lengthening of the monitoring period. This performance improvement should be reasonably balanced against an unnecessary prolonged ‘time free’ with only a marginal gain in performance. Recommendations are provided for minimum monitoring periods leading to minimal failure rates of the Exit Strategy. The proposed Exit Strategy would fail with the presence of lifelong infectious wild boar. That said, it should be emphasised that the existence of such animals is speculative, based on current knowledge.

To evaluate and compare the risk of emerging vector-borne diseases (VBDs), a Model for INTegrated RISK assessment, MINTRISK, was developed to assess the introduction risk of VBDs for new regions in an objective, transparent and repeatable manner. MINTRISK is a web-based calculation tool, that provides semi-quantitative risk scores that can be used for prioritization purposes. Input into MINTRISK is entered by answering questions regarding entry, transmission, establishment, spread, persistence and impact of a selected VBD. Answers can be chosen from qualitative answer categories with accompanying quantitative explanation to ensure consistent answering. The quantitative information is subsequently used as input for the model calculations to estimate the risk for each individual step in the model and for the summarizing output values (rate of introduction; epidemic size; overall risk). The risk assessor can indicate his uncertainty on each answer, and this is accounted for by Monte Carlo simulation. MINTRISK was used to assess the risk of four VBDs (African horse sickness, epizootic haemorrhagic disease, Rift Valley fever, and West Nile fever) for the Netherlands with the aim to prioritise these diseases for preparedness. Results indicated that the overall risk estimate was very high for all evaluated diseases but epizootic haemorrhagic disease. Uncertainty intervals were, however, wide limiting the options for ranking of the diseases. Risk profiles of the VBDs differed. Whereas all diseases were estimated to have a very high economic impact once introduced, the estimated introduction rates differed from low for Rift Valley fever and epizootic haemorrhagic disease to moderate for African horse sickness and very high for West Nile fever. Entry of infected mosquitoes on board of aircraft was deemed the most likely route of introduction for West Nile fever into the Netherlands, followed by entry of infected migratory birds.

Abstract The European Commission requested EFSA to provide study designs for the investigation of four research domains according to major gaps in knowledge identified by EFSA in a report published in 2019: i) the patterns of seasonality of ASF in wild boar and domestic pigs in the EU; ii) the ASF epidemiology in wild boar; iii) ASF virus (ASFV) survival in the environment and iv) ASF transmission by vectors. In this Scientific Opinion, the first research domain on ASF seasonality is addressed. Therefore, five research objectives were proposed by the working group and broader ASF expert networks, such as ASF stop, ENETWILD, VectorNet, AHAW network and the AHAW Panel Experts. Of the five research objectives, only two were prioritised and elaborated into a general protocol/study design research proposal, namely: 1) to monitor the herd incidence of ASF outbreaks in EU Member States (MS) and 2) to investigate potential (seasonal) risk factors for ASF incursion in domestic pig herds of different herd types and/or size. To monitor the incidence in different pig herd types, it is advised to collect, besides ASF surveillance data, pig population data describing at least the following parameters per farm from the first moment of incursion in an affected MS: the numbers of pigs (e.g. number of breeding pigs sows and boars, weaners and fatteners) and the location and the type of farm (including details on the level of biosecurity implemented on the farm and the outdoor/indoor production). We suggest collecting data from all ASF‐affected MS through the SIGMA data model, which was developed for this purpose. To investigate potential risk factors for ASF incursion in domestic pig herds, we suggest a matched case–control design. Such a study design can be run either retrospectively or prospectively. The collected data on the pig herds and the ASF surveillance data in the SIGMA data model can be used to identify case and control farms.

The European Commission asked EFSA to provide study designs for the investigation of four research domains (RDs) according to major gaps in knowledge identified by EFSA in a report published in 2019: (RD 1) African swine fever (ASF) epidemiology in wild boar; (RD 2) ASF transmission by vectors; (RD 3) African swine fever virus (ASFV) survival in the environment, and (RD 4) the patterns of seasonality of ASF in wild boar and domestic pigs in the EU. In this Scientific Opinion, the second RD on ASF epidemiology in wild boar is addressed. Twenty-nine research objectives were proposed by the working group and broader ASF expert networks and 23 of these research objectives met a prespecified inclusion criterion. Fourteen of these 23 research objectives met the predefined threshold for selection and so were prioritised based on the following set of criteria: (1) the impact on ASF management; (2) the feasibility or practicality to carry out the study; (3) the potential implementation of study results in practice; (4) a possible short time-frame study (< 1 year); (5) the novelty of the study; and (6) if it was a priority for risk managers. Finally, after further elimination of three of the proposed research objectives due to overlapping scope of studies published during the development of this opinion, 11 research priorities were elaborated into short research proposals, considering the potential impact on ASF management and the period of one year for the research activities.