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An emphasis on biosecurity in the cattle industry was made over the years to improve animal and public health. Nevertheless, the level of implementation of biosecurity measures (BSM) remains largely insufficient due to certain constraints. It is therefore necessary to prioritize the different BSM to be applied in accordance with the individual context and the main infectious diseases affecting cattle. Previous prioritization exercises of infectious diseases were neither specific to Belgium nor based on an exhaustive list of diseases. This study aimed at classifying the most important infectious diseases affecting cattle in Belgium. A list of 74 cattle infectious diseases reported in Europe was compiled based on a literature review. Through an online survey, Belgian rural veterinary practitioners (RVP) were asked to assign a score to each disease according to their frequency (question 1), their trends estimated between 2013‐15 (question 2), and finally to list the five most important diseases for adult cattle (question 3). Respectively, 107 and 93 RVP answered the first two questions and the last one. Results of the survey were used to classify the diseases based on their frequency, trends, and importance through an additional weighting system and a subsequent regression tree analysis. Belgian laboratory databases and previous disease prioritization exercises were also analysed and taken into account as additional data sources. For the most important diseases identified (those ranked as important by the three data sources), a literature review was performed in PubMed to identify their related risk factors and BSM. A total of 48 infectious diseases were classified as important in Belgium with six of them considered as important from the three data sources: bovine respiratory diseases (BRD), bovine respiratory syncytial virus (BRSV), bovine viral diarrhoea (BVD), infectious bovine rhinotracheitis (IBR), Q fever, and salmonellosis. Their related BSM should be prioritized in terms of BSM implementation.

Picornaviruses are small, roughly spherical viruses with a protein shell. The picornavirus genome includes two untranslated regions, one preceding and one following the single open reading frame (ORF). The ORF is translated into a polyprotein that is usually processed by one or two virus-encoded proteinases. The variety of diseases caused by picornaviruses ranges from acute and sometimes fatal paralysis to mild respiratory disease and to inapparent infections in many hosts. Foot-and-mouth disease is a severe, clinically acute vesicular disease of cloven-hoofed animals, including domesticated and wild swine and ruminants. Swine vesicular disease virus (SVDV) is classified as an enterovirus within the family Picornaviridae and belongs to the species Enterovirus B. Like other picornaviruses, SVDV is non-enveloped. Encephalomyocarditis virus (EMCV) were subsequently detected in a variety of animal species. The impact of EMCV on public health is believed to be minimal.

Currently no live DIVA (Differentiating Infected from Vaccinated Animals) vaccines against classical swine fever (CSF) are available. The aim of this study was to investigate whether chimeric pestivirus vaccine candidates (CP7_E2alf, Flc11 and Flc9) are able to protect pigs against clinical signs, and to reduce virus shedding and virus transmission, after a challenge with CSF virus (CSFV), 7 or 14 days after a single intramuscular vaccination. In these vaccine candidates, either the E2 or the E(rns) encoding genome region of a bovine viral diarrhoea virus strain were combined with a cDNA copy of CSFV or vice versa. Furthermore, currently available serological DIVA tests were evaluated. The vaccine candidates were compared to the C-strain. All vaccine candidates protected against clinical signs. No transmission to contact pigs was detected in the groups vaccinated with C-strain, CP7_E2alf and Flc11. Limited transmission occurred in the groups vaccinated with Flc9. All vaccine candidates would be suitable to stop on-going transmission of CSFV. For Flc11, no reliable differentiation was possible with the current E(rns)-based DIVA test. For CP7_E2alf, the distribution of the inhibition percentages was such that up to 5% false positive results may be obtained in a large vaccinated population. For Flc9 vaccinated pigs, the E2 ELISA performed very well, with an expected 0.04% false positive results in a large vaccinated population. Both CP7_E2alf and Flc9 are promising candidates to be used as live attenuated marker vaccines against CSF, with protection the best feature of CP7_E2alf, and the DIVA principle the best feature of Flc9.

International audience; Bluetongue (BT) is a viral vector-borne disease affecting domestic and wild ruminants worldwide. In this study, a commercial rapid immuno-chromatographic method or Lateral Flow Test (LFT) device, for the detection of BT virus-specific antibodies in animal serum, was evaluated in an international inter laboratory proficiency test. The evaluation was done with sera samples of variable background (ruminant species, serotype, field samples, experimental infections, vaccinated animals). The diagnostic sensitivity was 100% (95% C.I. [90.5-100]) and the diagnostic specificity was 95.2% (95% C.I. [76.2-99.9]). The repeatability (accordance) and reproducibility (concordance) were 100% for seropositive samples but were lower for two of the seronegative samples (45% and 89% respectively). The analytical sensitivity, evaluated by testing positive sera at increasing dilutions was better for the BT LFT compared to some commercial ELISAs. Seroconversion of an infected sheep was detected at 4 days post infection. Analytical specificity was impaired by cross-reactions observed with some of the samples seropositive for Epizootic Haemorrhagic Disease Virus (EHDV). The agreement (Cohen's kappa) between the LFT and a commercial BT competitive ELISA was 0.79 (95% CI [0.62-0.95]). Based on these results, it can be concluded that the BT LFT device is a rapid and sensitive first-line serological test that can be used in the field, especially in areas endemic for the disease where there is a lack of diagnostic facilities.

Classical swine fever (CSF) is among the most detrimental diseases for the swine industry worldwide. Infected wild boar populations can play a crucial role in CSF epidemiology and controlling wild reservoirs is of utmost importance for preventing domestic outbreaks. Oral mass vaccination (OMV) has been implemented to control CSF in wild boars and limit the spill over to domestic pigs. This retrospective overview of vaccination experiences illustrates the potential for that option. The C-strain live vaccine was confirmed to be highly efficacious and palatable baits were developed for oral delivery in free ranging wild boars. The first field trials were performed in Germany in the 1990’s and allowed deploying oral baits at a large scale. The delivery process was further improved during the 2000’s among different European countries. Optimal deployment has to be early regarding disease emergence and correctly designed regarding the landscape structure and the natural food sources that can compete with oral baits. OMV deployment is also highly dependent on a local veterinary support working closely with hunters, wildlife and forestry agencies. Vaccination has been the most efficient strategy for CSF control in free ranging wild boar when vaccination is wide spread and lasting for a sufficient period of time. Alternative disease control strategies such as intensified hunting or creating physical boundaries such as fences have been, in contrast, seldom satisfactory and reliable. However, monitoring outbreaks has been challenging during and after vaccination deployment since OMV results in a low probability to detect virus-positive animals and the live-vaccine currently available does not allow serological differentiation of infected from vaccinated animals. The development of a new marker vaccine and companion test is thus a promising option for better monitoring outbreaks during OMV deployment as well as help to better determine when to stop vaccination efforts. After rabies in red fox, the use of OMV against CSF in European wild boar can be considered as a second example of successful disease control in wildlife. The thirty years of disease control experience included in this review may provide options for improving future disease management within wild populations.

International audience; Syndromic surveillance is considered as one of the surveillance components for early warning of health-related events, as it allows detection of aberrations in health indicators before laboratory confirmation. "MoSS-Emergences 2" (MoSS-E2), a tool for veterinary syndromic surveillance, aggregates groups of similar clinical observations by hierarchical ascendant classification (HAC). In the present study, this HAC clustering process was evaluated using a reference set of data that, for the purpose of this evaluation, was a priori divided and defined as Bluetongue (BTV) positive cases (PC) on the one hand and BTV negative cases (NC) on the other hand. By comparing the clustering result of MoSS-E2 with the expected outcome, the sensitivity (the ability to cluster PC together) and specificity (the ability to exclude NC from PC) of the clustering process were determined for this set of data. The stability of the classes obtained with the clustering algorithm was evaluated by comparing the MoSS-E2 generated dendrogram (applying complete linkage) with dendrograms of STATA(®) software applying average and single linkage methods. To assess the systems' robustness, the parameters of the distance measure were adjusted according to different scenarios and obtained outcomes were compared to the expected outcome based on the a priori known labels. Rand indexes were calculated to measure similarity between clustering outcomes. The clustering algorithm in its default settings successfully segregated the reference BTV cases from the non-BTV cases, resulting in a sensitivity of 100.0% (95% CI: 89.0-100.0) and a specificity of 100.0% (95% CI: 80.0-100.0) for this set of data. The different linkage methods showed similar clustering results indicating stability of the classes (Rand indexes of respectively 0.77 for average and 0.75 for single linkage). The system proved to be robust when changing the parameters as the BTV cases remained together in meaningful clusters (Rand indexes between 0.72 and 1). The configurable MoSS-E2 system demonstrated its suitability to identify meaningful clusters of clinical syndromes.

Pigs have a need for manipulable materials to satisfy a range of behavioural needs, which can be different in different classes of pig. When these needs are not met, a range of adverse welfare consequences result, one of these being an increased risk for tail-biting in weaners and rearing pigs. The ability to control the risk of tail-biting is essential when aiming to avoid tail-docking. Based on available scientific information this Opinion identifies the multiple interactions between risk factors, welfare consequences and animal and non-animal-based measures on the two subjects requested (i) the absence of functional manipulable materials, for pigs at different stages in life and (ii) tail-biting, for weaners and rearing pigs only. An attempt is made to quantify the relationships between the identified interactions by carrying out a statistical analysis of information from available databases, those being an international dataset collected using the Welfare Quality® protocol, which was not designed to evaluate risk factors for tail-biting and therefore, it had limitations in fitness for this analysis, and a large Finnish dataset with undocked pigs. Based on the current state of knowledge, the AHAW Panel proposes two simple tool-boxes for on farm use to assess (i) the functionality of the supplied manipulable material and (ii) the presence and strength of risk factors for tail biting. Both proposed tool-boxes include a combination of the most important resource-based and animal-based measures. Further development and validation of decision–support tools for customised farm assessment is strongly recommended and a proposal for harmonised data collection across the range of European farming circumstances is presented. A series of further recommendations are made by the AHAW Panel.

Small hive beetle (SHB) and Tropilaelaps are bee diseases considered exotic in the EU. SHBis a flying coleopteran that can be attracted to the odours of bees and bee products. In addition, SHB can survive and reproduce on a variety of ripe fruits. Tropilaelaps is an ectoparasite that does not survive long without honey bee brood and cannot fly by itself. The methodology used to assess the risk of entry of these pests in this scientific opinion was adapted from a pest risk assessment for entry used in the field of plant health. A qualitative risk assessment was performed taking into account current legislation but excluding the implementation of risk reduction options. This approach allowed the assessment of the worst case scenario for each risk factor. The risk pathways with a high risk of pest entry are ‘import of bee products (use in apiculture)’ for SHB and ‘accidental import of bees’ (unintended presence of bees in a non-bee consignment) for both pests. The other risk pathways are associated with a moderate or low risk of SHB or Tropilaelaps entry into the risk assessment area. Risk reduction options were assessed separately from the risk assessment. Examples of risk reduction options with a high effectiveness and a high technical feasibility are the use of health certificates to guarantee pest freedom of consignments and keeping consignments without honey bee brood. Options with a high effectiveness and technical feasibility were identified in all risk pathways except ‘accidental import of bees’ and ‘dispersal of the pest via natural means and/or flight’. The AHAW Panel identified the need for validated rapid detection methods and for handling and sampling of imported bees in insect-proof environments. Education and training could help to monitor the pest distribution and to prevent pest entry by improving awareness, skills and expertise.

This scientific opinion proposes toolboxes of welfare indicators for developing monitoring procedures at slaughterhouses for bovines stunned with penetrative captive bolt or slaughtered without stunning. In particular, the opinion proposes welfare indicators together with their corresponding outcomes of consciousness, unconsciousness or death. In the case of slaughter with captive bolt stunning, the opinion proposes a toolbox of indicators and the outcomes to be used to assess consciousness in bovine animals at three key stages of monitoring: (a) after stunning and during shackling and hoisting; (b) during neck cutting or sticking; and (c) during bleeding. For slaughter of bovines without stunning, a set of indicators and outcomes are proposed in another toolbox to be used for (a) assessing unconsciousness, before releasing bovines from restraint; and (b) confirming death before carcass dressing begins. Various activities‐including a systematic literature review, an online survey and stakeholders’ and hearing experts’ meetings‐were conducted to gather information about the specificity, sensitivity and feasibility of the indicators that can be included in the toolboxes. The frequency of checking differs according to the role of each person responsible for ensuring animal welfare. Personnel performing stunning, shackling, hoisting and/or bleeding will have to check all the animals and confirm that they are not conscious following stunning or before release from the restraint. For the animal welfare officer, who has the overall responsibility for animal welfare, a mathematical model for the sampling protocols is proposed, giving some allowance to set the sample size of animals that he/she needs to check at a given throughput rate (total number of animals slaughtered in the slaughterhouse) and tolerance level (number of potential failures). Finally, different risk factors and scenarios are proposed to define a ‘normal’ or a ‘reinforced’ monitoring protocol, according to the needs of the slaughterhouse.

This guidance defines the assessment process and the criteria that will be applied by the Animal Health and Welfare Panel to studies on known new or modified legal stunning interventions to determine their suitability for further assessment. The criteria that need to be fulfilled are eligibility criteria, reporting quality criteria and methodological quality criteria. The eligibility criteria are based upon the legislation and previously published scientific data. They focus on the intervention and the outcomes of interest, i.e. immediate onset of unconsciousness and insensibility or absence of avoidable pain, distress and suffering until the loss of consciousness and sensibility, and duration of the unconsciousness and insensibility (until death). If a study fulfils the eligibility criteria, it will be assessed regarding a set of reporting quality criteria that are based on the REFLECT and the STROBE statements. As a final step in this first assessment phase, the methodological quality of the submitted study will be assessed. If the criteria regarding eligibility, reporting quality and methodological quality are fulfilled, a full assessment of the animal welfare implications of the proposed alternative stunning intervention, including both pre‐stunning and stunning phases, and an evaluation of the quality, strength and external validity of the evidence presented would be carried out at the next level of the assessment. In the case that the criteria regarding eligibility and reporting quality and methodological quality are not fulfilled, the assessment report of the panel will highlight the shortcomings and indicate where improvements are required before the study can be assessed further. In addition to the assessment criteria, the guidance also specifies general aspects applicable to studies on stunning interventions that should be considered when studying the effectiveness of stunning interventions.

This scientific opinion proposes toolboxes of welfare indicators for developing monitoring procedures at slaughterhouses for sheep and goats stunned with the head‐only electrical method or slaughtered without stunning. In particular, the opinion proposes welfare indicators together with their corresponding outcomes of consciousness, unconsciousness or death. In the case of slaughter with head‐only electrical stunning, the opinion proposes a toolbox to assess consciousness at three key stages of monitoring: (a) after electrical stunning and during shackling and hoisting, (b) during neck cutting and (c) during bleeding. For slaughter without stunning, another toolbox is proposed for (a) assessing unconsciousness before releasing the animals from restraint, and (b) confirming death before carcass dressing begins. Various activities‐including a systematic literature review, an online survey and stakeholders’ and hearing experts’ meetings‐were conducted to gather information about the sensitivity, specificity and feasibility of the indicators. On the basis of such information, a methodology was developed to select the most appropriate indicators to be used in the monitoring procedures. The frequency of checking differs according to the role of each person with responsibility for ensuring animal welfare. The personnel performing stunning, shackling, hoisting and/or bleeding will have to check all the animals and confirm that they are not conscious following stunning or before releasing from the restraint. For the animal welfare officer, who has the overall responsibility for animal welfare, a mathematical model for the sampling protocols is proposed, giving some allowance to set the sample size of animals to be checked at a given throughput rate (total number of animals slaughtered in the slaughterhouses) and threshold failure rate (number of potential failures‐proportion of animals that are conscious after stunning). Finally, different risk factors and scenarios are proposed to define a ‘normal’ or a ‘reinforced’ monitoring protocol, according to the needs of the slaughterhouse.

This chapter contains sections titled: Introduction, Foot- and -Mouth Disease, Swine Vesicular Disease Virus, Encephalomyocarditis, Ljungan Virus Infection and References.-- et al.

Ethyl 2-methylimidazo[1,2- a ]pyrrolo[2,3- c ]pyridin-8-carboxylate (AG110) was identified as a potent inhibitor of pestivirus replication. The 50% effective concentration values for inhibition of bovine viral diarrhea virus (BVDV)-induced cytopathic effect, viral RNA synthesis, and production of infectious virus were 1.2 ± 0.5 μM, 5 ± 1 μM, and 2.3 ± 0.3 μM, respectively. AG110 proved inactive against the hepatitis C virus and a flavivirus. AG110 inhibits BVDV replication at a time point that coincides with the onset of intracellular viral RNA synthesis. Drug-resistant mutants carry the E291G mutation in the viral RNA-dependent RNA polymerase (RdRp). AG110-resistant virus is cross-resistant to the cyclic urea compound 1453 which also selects for the E291G drug resistance mutation. Moreover, BVDV that carries the F224S mutation (because of resistance to the imidazopyridine 5-[(4-bromophenyl)methyl]-2-phenyl-5 H -imidazo[4,5- c ]pyridine [BPIP]and VP32947) is also resistant to AG110. AG110 did not inhibit the in vitro activity of recombinant BVDV RdRp but inhibited the activity of BVDV replication complexes (RCs). Molecular modeling revealed that E291 is located in a small cavity near the tip of the finger domain of the RdRp about 7 Å away from F224. Docking of AG110 in the crystal structure of the BVDV RdRp revealed several potential contacts including with Y257. The E291G mutation might enable the free rotation of Y257, which might in turn destabilize the backbone of the loop formed by residues 223 to 226, rendering more mobility to F224 and, hence, reducing the affinity for BPIP and VP32947. It is concluded that a single drug-binding pocket exists within the finger domain region of the BVDV RdRp that consists of two separate but potentially overlapping binding sites rather than two distinct drug-binding pockets.

We set up a matched case-control study of potential risk factors for clinical encephalomyocarditis virus (EMCV) in 58 pig farms in West Flanders (Belgium). In total, 29 farms experienced a clinical outbreak of EMCV confirmed by EMC virus isolation. Mortality was seen only among suckling piglets (18 case farms), in piglets and other age-groups (4 case farms), or only among fattening pigs (7 case farms). Five farms had reproductive problems among the sows. Control farms were matched geographically on farm size and farm type and were selected on the absence of clinical signs. A questionnaire on potential risk factors for EMCV was developed to collect data at both case and control farms. The exploration of the data used clusters of factors associated with clinical EMCV infection: (a) rodents, (b) general farm set up and (c) general hygiene. The multivariable relationships between clinical appearance of EMCV and potential risk factors were tested with conditional logistic regression. The final model on all farms contained presence of mice (OR = 8.3) as a risk factor for clinical EMCV infection while the flow of manure up through the slatted floor (OR = 0.11) and movement of manure between manure pits in the pig stable (OR = 0.14) were protective. (c) 2006 Elsevier B.V. All rights reserved.

We report on the highly potent and selective antipestivirus activity of 5-[(4-bromophenyl)methyl]-2-phenyl-5 H -imidazo[4,5-c]pyridine (BPIP). The 50% effective concentration (EC 50 ) for inhibition of bovine viral diarrhea virus (BVDV)-induced cytopathic effect formation was 0.04 ± 0.01 μM. Comparable reduction of viral RNA synthesis (EC 50 = 0.12± 0.02 μM) and production of infectious virus (EC 50 = 0.074 ± 0.003 μM) were observed. The selectivity index (ratio of 50% cytostatic concentration/EC 50 ) of BPIP was ∼2,000. BPIP was inactive against the hepatitis C virus subgenomic replicon and yellow fever virus but demonstrated weak activity against GB virus. Drug-resistant mutants were at least 300-fold less susceptible to BPIP than wild-type virus; showed cross-resistance to N -propyl- N -[2-(2 H -1,2,4-triazino[5,6-b]indol-3-ylthio)ethyl]-1-propanamine (VP32947), and carried the F224S mutation in the viral RNA-dependent RNA polymerase (RdRp). When the F224S mutation was introduced into an infectious clone, the drug-resistant phenotype was obtained. BPIP did not inhibit the in vitro activity of recombinant BVDV RdRp, but did inhibit the activity of replication complexes (RCs). Computational docking revealed that F224 is located at the top of the finger domain of the polymerase. Docking of BPIP in the crystal structure of the BVDV RdRp revealed aromatic ring stacking, some hydrophobic contacts, and a hydrogen bond. Since two structurally unrelated compounds, i.e., BPIP and VP32947, target the same region of the BVDV RdRp, this position may be expected to be critical in the functioning of the polymerase or assembly of the RC. The potential of BPIP for the treatment of pestivirus and hepacivirus infections is discussed.

International audience; The occurrence of encephalomyocarditis virus (EMCV) among domestic pigs and wild boar in several European countries is described and discussed. From 1990 to 2001 clinical outbreaks were analysed and serum samples, partly from existing screening programmes, were tested for antibodies against EMCV. Most clinical EMCV outbreaks were reported in Belgium (320), followed by Italy (110), Greece (15) and Cyprus (6). The outbreaks appeared to be clustered in,endemic areas' with an increase in outbreaks during the autumn and winter months. The within-herd seroprevalence measured in clinically affected pig farms varied considerably among farms (2.87%), with age (0.84%) and by country. Data from farms with no clinical disease showed that subclinical infection with EMCV was found both within (seroprevalence 6.62%) and outside (up to 17%) the endemic areas of the clinically affected countries as well as in the non-clinically affected countries Austria and France (3-5.4%). Among wild boar, the seroprevalence varied between 0.6 and 10.8%, and a study in Belgium found a prevalence of virus infection of 3.3%.

International audience; - Due to the probable role played by rodents as a reservoir for the transmission of the EMC virus to pigs, the experiment reported here was performed in order to assess the transmission rate of EMCV within a rat population. Twenty-five eight-week-old Wistar rats housed in individual plastic cages were experimentally infected either with a Greek myocardial EMCV strain (5 rats with a 0.2 $\times$ 106 TCID50 dose per rat and 10 rats with a 0.5 $\times$ 104.5 TCID50 dose per rat, oronasally) or a Belgian myocardial EMCV strain (10 rats with a 0.5 $\times$ 104.5 TCID50 dose per rat, oronasally). Two to five days later, each inoculated rat was moved to a new clean cage and coupled with a contact rat to compare the pathogenicity of the two strains and to estimate the basic reproduction ratio R0, indicating the level of EMCV transmission. During the experiments, faecal virus excretion was measured as well as the serological response against EMCV. After euthanasia, virus isolation was attempted from different rat tissues. Neither strains produced mortality, nor clinical signs and only low titres of neutralising antibodies were found. All contact rats, however, were infected and the virus was isolated from their faeces and from various tissues. Both 10-pair experiments revealed a point estimate for the R0 of $\infty$ (95%-CI for both the Greek and Belgian EMCV strains = 4.48 - $\infty$), as did the 5-pair experiment with a higher dose of the Greek strain (95%-CI = 1.83 - $\infty$). Combining the results from the two 10-pair experiments resulted in an estimate for R0 of $\infty$ (95%-CI: 9.87 - $\infty$). These results indicate that the EMC virus can spread very easily within a rat population by horizontal rat-to-rat transmission (R0 >> 1).

A big epidemic of classical swine fever (CSF) occurred in the European Community in 1997. The first case was reported at the beginning of January 1997 from Germany. The disease presumably spread to the Netherlands, and from there to Italy, Spain and eventually to Belgium. About 30 isolates from these outbreaks were analysed by comparison of the nucleotide sequence data generated from fragments of both the E2 glycoprotein gene (190 nucleotides) and from the 5'-nontranslated region (5'-NTR; 150 nucleotides). By combining epidemiological data with genetic typing, it was found that the outbreaks were related and caused by a virus belonging to the genetic subgroup 2.1. As this type of virus had been reported infrequently in Europe and not at all since 1993, we postulate that it was newly introduced into the European Union (EU). (C) 2000 Elsevier Science B.V.

Background The aim of this study was to compare the tissue distribution and pathogenicity of three virulence variants of classical swine fever virus (CSFV) and to investigate the applicability of various conventional diagnostic procedures. Methods 64 pigs were divided into three groups and infected with the highly virulent isolate ISS/60, the moderately virulent isolate Wingene'93 and the live attenuated vaccine strain Riems, respectively. Clinical signs, gross and histopathological changes were compared in relation to time elapsed post infection. Virus spread in various organs was followed by virus isolation, by immunohistochemistry, applying monoclonal antibodies in a two-step method and by in situ hybridisation using a digoxigenin-labelled riboprobe. Results The tissue distribution data are discussed in details, analyzing the results of the various diagnostic approaches. The comparative studies revealed remarkable differences in the onset of clinical signs as well as in the development of the macro- and microscopical changes, and in the tissue distribution of CSFV in the three experimental groups. Conclusion The present study demonstrates that in the case of highly and moderately virulent virus variants the virulence does not affect the pattern of the viral spread, however, it influences the outcome, the duration and the intensity of the disease. Immunohistochemistry has the advantage to allow the rapid detection and localisation of the virus, especially in cases of early infection, when clinical signs are still absent. Compared to virus isolation, the advantage of this method is that no cell culture facilities are required. Thus, immunohistochemistry provides simple and sensitive tools for the prompt detection of newly emerging variants of CSFV, including the viruses of very mild virulence.