If You're Not Confused, You're Not Paying Attention: Ochrobactrum Is Not Brucella.

Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, a group of taxonomists merged the brucellae with the primarily free-living, phylogenetically related Ochrobactrum spp. in the genus Brucella. This change, founded only on global genomic analysis and the fortuitous isolation of some opportunistic Ochrobactrum spp. from medically compromised patients, has been automatically included in culture collections and databases. We argue that clinical and environmental microbiologists should not accept this nomenclature, and we advise against its use because (i) it was presented without in-depth phylogenetic analyses and did not consider alternative taxonomic solutions; (ii) it was launched without the input of experts in brucellosis or Ochrobactrum; (iii) it applies a non-consensus genus concept that disregards taxonomically relevant differences in structure, physiology, population structure, core-pangenome assemblies, genome structure, genomic traits, clinical features, treatment, prevention, diagnosis, genus description rules, and, above all, pathogenicity; and (iv) placing these two bacterial groups in the same genus creates risks for veterinarians, medical doctors, clinical laboratories, health authorities, and legislators who deal with brucellosis, a disease that is particularly relevant in low- and middle-income countries. Based on all this information, we urge microbiologists, bacterial collections, genomic databases, journals, and public health boards to keep the Brucella and Ochrobactrum genera separate to avoid further bewilderment and harm.

Brucella melitensis Rev.1 vaccination generates a higher shedding risk of the vaccine strain in Alpine ibex (Capra ibex) compared to the domestic goat (Capra hircus).

Epidemiological investigations implemented in wild and domestic ruminants evidenced a reservoir for Brucella in Capra ibex in the French Alps. Vaccination was considered as a possible way to control Brucella infection in this wildlife population. Twelve ibexes and twelve goats were allocated into four groups housed separately, each including six males or six non-pregnant females. Four to five animals were vaccinated and one or two animals were contact animals. Half of the animals were necropsied 45 days post-vaccination (pv), and the remaining ones at 90 days pv. Additional samples were collected 20 and 68 days pv to explore bacterial distribution in organs and humoral immunity. Neither clinical signs nor Brucella-specific lesions were observed and all vaccinated animals seroconverted. Brucella distribution and antibody profiles were highly contrasted between both species. Proportion of infected samples was significantly higher in ibex compared to goats and decreased between 45 and 90 days pv. Two male ibex presented urogenital excretion at 20 or 45 days pv. The bacterial load was higher 45 days in ibexes compared to goats, whereas it remained moderate to low 90 days pv in both species with large variability between animals. In this experiment, differences between species remained the main source of variation, with low impact of other individual factors. To conclude, multiplicative and shedding capacity of Rev.1 was much higher in ibex compared to goats within 90 days. These results provide initial information on the potential use in natura of a commercial vaccine.

Contagious epididymitis due to Brucella ovis: relationship between sexual function, serology and bacterial shedding in semen.

BACKGROUND: Contagious Epididymitis (CE) due to Brucella ovis (B. ovis) is a contagious disease that impairs rams' fertility due to epididymis, testicle and accessory sexual gland alterations. An increased incidence of CE has been observed in South Eastern France ("PACA" region) since the Rev.1 vaccination against B. melitensis has been stopped in 2008. The objective of this study was to evaluate the relationship between the infection by B. ovis and the sexual function of rams. Two-hundred eighteen sexually-mature rams, from 11 seropositive flocks, were submitted to a clinical examination of the genital tract, a semen collection by electro-ejaculation for spermogram and culture, and a serological examination for anti-B. ovis antibodies by complement fixation test (CFT) and indirect ELISA (I-ELISA). The relationships between clinical, seminal, bacteriological and serological parameters were studied using the Fisher exact test and a logistic regression model (binomial logit). RESULTS: B. ovis shedding in semen was significantly associated with seropositivity (CFT and I-ELISA; p < 0.001 and 0.01 respectively), genital tract alterations (p < 0.05) and poor semen quality (p < 0.001). Seropositive rams presented significantly more genital tract alterations (p < 0.001) and a poor seminal score (p < 0.001) than seronegative rams. CONCLUSIONS: Since semen culture is not routinely feasible in field conditions, a control plan of CE should be based, where Rev.1 vaccination is not possible, on both systematic clinical and serological examination of rams, followed by the culling of seropositive and/or genital tract alterations carrier rams.

Examination of taxonomic uncertainties surrounding Brucella abortus bv. 7 by phenotypic and molecular approaches.

Brucella taxonomy is perpetually being reshuffled, at both the species and intraspecies levels. Biovar 7 of Brucella abortus was suspended from the Approved Lists of Bacterial Names Brucella classification in 1988, because of unpublished evidence that the reference strain 63/75 was a mixture of B. abortus biovars 3 and 5. To formally clarify the situation, all isolates previously identified as B. abortus bv. 7 in the AHVLA and ANSES strain collections were characterized by classical microbiological and multiple molecular approaches. Among the 14 investigated strains, including strain 63/75, only four strains, isolated in Kenya, Turkey, and Mongolia, were pure and showed a phenotypic profile in agreement with the former biovar 7, particularly agglutination with both anti-A/anti-M monospecific sera. These results were strengthened by molecular strategies. Indeed, genus- and species-specific methods allowed confirmation that the four pure strains belonged to the B. abortus species. The combination of most approaches excluded their affiliation with the recognized biovars (biovars 1 to 6 and 9), while some suggested that they were close to biovar 3.These assays were complemented by phylogenetic and/or epidemiological methods, such as multilocus sequence analysis (MLSA) and variable-number tandem repeat (VNTR) analysis. The results of this polyphasic investigation allow us to propose the reintroduction of biovar 7 into the Brucella classification, with at least three representative strains. Interestingly, the Kenyan strain, sharing the same biovar 7 phenotype, was genetically divergent from other three isolates. These discrepancies illustrate the complexity of Brucella taxonomy. This study suggests that worldwide collections could include strains misidentified as B. abortus bv. 7, and it highlights the need to verify their real taxonomic position.

Vaccination of poultry against highly pathogenic avian influenza - Part 2. Surveillance and mitigation measures.

Selecting appropriate diagnostic methods that take account of the type of vaccine used is important when implementing a vaccination programme against highly pathogenic avian influenza (HPAI). If vaccination is effective, a decreased viral load is expected in the samples used for diagnosis, making molecular methods with high sensitivity the best choice. Although serological methods can be reasonably sensitive, they may produce results that are difficult to interpret. In addition to routine molecular monitoring, it is recommended to conduct viral isolation, genetic sequencing and phenotypic characterisation of any HPAI virus detected in vaccinated flocks to detect escape mutants early. Following emergency vaccination, various surveillance options based on virological testing of dead birds ('bucket sampling') at defined intervals were assessed to be effective for early detection of HPAIV and prove disease freedom in vaccinated populations. For ducks, virological or serological testing of live birds was assessed as an effective strategy. This surveillance could be also applied in the peri-vaccination zone on vaccinated establishments, while maintaining passive surveillance in unvaccinated chicken layers and turkeys, and weekly bucket sampling in unvaccinated ducks. To demonstrate disease freedom with > 99% confidence and to detect HPAI virus sufficiently early following preventive vaccination, monthly virological testing of all dead birds up to 15 per flock, coupled with passive surveillance in both vaccinated and unvaccinated flocks, is recommended. Reducing the sampling intervals increases the sensitivity of early detection up to 100%. To enable the safe movement of vaccinated poultry during emergency vaccination, laboratory examinations in the 72 h prior to the movement can be considered as a risk mitigation measure, in addition to clinical inspection; sampling results from existing surveillance activities carried out in these 72 h could be used. In this Opinion, several schemes are recommended to enable the safe movement of vaccinated poultry following preventive vaccination.

The use of high expansion foam for stunning and killing pigs and poultry.

The EFSA Panel on Animal Health and Welfare (AHAW) was asked to deliver a scientific opinion on the use of high-expansion foam for stunning and killing pigs and poultry. A dossier was provided by the applicant as the basis for an assessment of the extent to which the method is able to provide a level of animal welfare at least equivalent to that ensured by the currently allowed methods for pigs and poultry. According to legislation, to be approved in the EU, new stunning methods must ensure (1) the absence of pain, distress or suffering until the onset of unconsciousness, and (2) that the animal remains unconscious until death. An ad hoc Working Group set up by EFSA performed the assessment as follows: (1) The data provided were checked against the criteria laid down in the EFSA Guidance (EFSA, 2018), and was found to partially fulfil those criteria; (2) extensive literature search; (3) data extraction for quantitative assessment; (4) qualitative exercise based on non-formal expert elicitation. The assessment led to conclude that it is more likely than not (certainty > 50%-100%) that high-expansion foam for stunning and killing pigs and poultry, named NEFS in container (Nitrogen Expansion Foam Stunning in container), provides a level of welfare at least equivalent to one or more of the currently allowed methods listed in Annex I of Council Regulation (EC) No 1099/2009. The overall assessment of EFSA is valid only under the technical conditions described in this Opinion for laying hens, broiler chickens of all age and pigs weighing 15-41 kg in situations other than slaughter. The overall assessment of EFSA is that NEFS can be suitable for depopulation using containers for pig and poultry farms respecting the technical conditions and the categories and types of animals defined in this Scientific Opinion.

Welfare of sheep and goats during killing for purposes other than slaughter.

Sheep and goats of different ages may have to be killed on-farm for purposes other than slaughter (where slaughter is defined as killing for human consumption) either individually (i.e. on-farm killing of unproductive, injured or terminally ill animals) or on a large scale (i.e. depopulation for disease control purposes and for other situations, such as environmental contamination and disaster management) outside the slaughterhouses. The purpose of this opinion was to assess the hazards and welfare consequences associated with the on-farm killing of sheep and goats. The whole killing procedure was divided into Phase 1 (pre-killing) - that included the processes (i) handling and moving the animals to the killing place and (ii) restraint of the animals before application of the killing methods and Phase 2 - that included stunning and killing of the animals. The killing methods for sheep and goats were grouped into three categories: (1) mechanical, (2) electrical and (3) lethal injection. Welfare consequences that sheep and goats may experience during each process were identified (e.g. handling stress, restriction of movements and tissue lesions during restraint) and animal-based measures (ABMs) to assess them were proposed. During application of the killing method, sheep and goats will experience pain and fear if they are ineffectively stunned or if they recover consciousness. ABMs related to the state of consciousness can be used to indirectly assess pain and fear. Flowcharts including ABMs for consciousness specific to each killing method were included in the opinion. Possible welfare hazards were identified for each process, together with their origin and related preventive and corrective measures. Outcome tables linking hazards, welfare consequences, ABMs, origins, preventive and corrective measures were developed for each process. Mitigation measures to minimise welfare consequences were proposed.

Evaluation of five serological tests for the diagnosis of porcine brucellosis in French Polynesia.

Porcine brucellosis due to Brucella suis biovar 1 raises important issues for pig breeders in French Polynesia. In this region, the disease is enzootic, spreads silently and engenders economic losses in infected farms as well as sporadic human cases. While serological tests are essential in surveillance and control programmes of animal diseases, to date none of the available tests have been shown to be reliable enough to be used as a gold standard in routine individual diagnosis of porcine brucellosis. Few studies about the estimation of the sensitivity and the specificity of porcine brucellosis screening tests have been published, none of them dealing with French Polynesia. The studied population included 1,595 pigs from French Polynesia. Five tests were evaluated: Rose Bengal test, fluorescence polarisation assay, indirect ELISA, and two competitive ELISAs (C-ELISA). The sensitivity and the specificity of each test were estimated. C-ELISA2 was the most sensitive test (Se C-ELISA2=0.954 [0.889; 0.992] 95% credibility interval (CrI)) while both C-ELISA and Rose Bengal test (RBT) were the most specific ones (Sp C-ELISA1=0.856 [0.806; 0.915] 95% CrI; Sp C-ELISA2=0.849 [0.817; 0.879] 95% CrI; Sp RBT=0.853 [0.812; 0.898] 95% CrI).

Evaluation of a Lateral Flow Immunochromatography Assay (LFIA) for Diagnosis and Surveillance of Brucellosis in French Alpine Ibex (Capra ibex).

France has been officially free of bovine brucellosis since 2005. Nevertheless, in 2012, as the source of two human cases, a bovine outbreak due to B. melitensis biovar 3 was confirmed in the French Alpine Bargy massif, due to a spillover from wild, protected Alpine ibex (Capra ibex). In order to reduce high Brucella prevalence in the local ibex population, successive management strategies have been implemented. Lateral flow immunochromatography assay (LFIA) was thus identified as a promising on-site screening test, allowing for a rapid diagnosis far from the laboratory. This study compared a commercial LFIA for brucellosis diagnosis with the WOAH-recommended tests for small ruminants (i.e., Rose Bengal test (RBT), Complement fixation test, (CFT) and Indirect ELISA, (iELISA)). LFIA showed the same analytical sensitivity as iELISA on successive dilutions of the International Standard anti-Brucella melitensis Serum (ISaBmS) and the EU Goat Brucella Standard Serum (EUGBSS). Selectivity was estimated at 100% when vaccinated ibex sera were analyzed. When used on samples from naturally infected ibex, LFIA showed high concordance, as well as relative sensitivity and specificity (>97.25%) in comparison with RBT and CFT. This work shows high reliability and ensures a better standardization of LFIA testing for wild ruminants.

[Brucellosis in Alpine ibex: 10 years of research and expert assessments]. / La brucellose du bouquetin des Alpes - Un exemple de dix années de recherche et d'expertise.

Brucellosis due to Brucella melitensis affects domestic and wild ruminants, as well as other mammals, including humans. Despite France being officially free of bovine brucellosis since 2005, two human cases of Brucella melitensis infection in the French Alps in 2012 led to the discovery of one infected cattle herd and of one infected population of wild Alpine ibex (Capra ibex). In this review, we present the results of 10 years of research on the epidemiology of brucellosis in this population of Alpine ibex. We also discuss the insights brought by research and expert assessments on the efficacy of disease management strategies used to mitigate brucellosis in the French Alps.

Title: La brucellose du bouquetin des Alpes - Un exemple de dix années de recherche et d'expertise. Abstract: La brucellose à Brucella melitensis touche les ruminants domestiques et sauvages, ainsi que d'autres mammifères, dont les humains. Bien que la France soit officiellement indemne depuis 2005, deux cas humains reportés en Haute-Savoie en 2012 ont conduit à la découverte de l'infection dans un élevage bovin et chez les bouquetins des Alpes (Capra ibex) du massif du Bargy. Nous présentons dans cette synthèse les principales découvertes de ces dix dernières années sur le système brucellose-bouquetins. Nous discuterons également de l'apport de la recherche et de l'expertise sur l'évaluation de l'efficacité des mesures de gestion sanitaire mises en place dans le massif du Bargy pour lutter contre la brucellose.

SARS-CoV-2 in animals: susceptibility of animal species, risk for animal and public health, monitoring, prevention and control.

The epidemiological situation of SARS-CoV-2 in humans and animals is continually evolving. To date, animal species known to transmit SARS-CoV-2 are American mink, raccoon dog, cat, ferret, hamster, house mouse, Egyptian fruit bat, deer mouse and white-tailed deer. Among farmed animals, American mink have the highest likelihood to become infected from humans or animals and further transmit SARS-CoV-2. In the EU, 44 outbreaks were reported in 2021 in mink farms in seven MSs, while only six in 2022 in two MSs, thus representing a decreasing trend. The introduction of SARS-CoV-2 into mink farms is usually via infected humans; this can be controlled by systematically testing people entering farms and adequate biosecurity. The current most appropriate monitoring approach for mink is the outbreak confirmation based on suspicion, testing dead or clinically sick animals in case of increased mortality or positive farm personnel and the genomic surveillance of virus variants. The genomic analysis of SARS-CoV-2 showed mink-specific clusters with a potential to spill back into the human population. Among companion animals, cats, ferrets and hamsters are those at highest risk of SARS-CoV-2 infection, which most likely originates from an infected human, and which has no or very low impact on virus circulation in the human population. Among wild animals (including zoo animals), mostly carnivores, great apes and white-tailed deer have been reported to be naturally infected by SARS-CoV-2. In the EU, no cases of infected wildlife have been reported so far. Proper disposal of human waste is advised to reduce the risks of spill-over of SARS-CoV-2 to wildlife. Furthermore, contact with wildlife, especially if sick or dead, should be minimised. No specific monitoring for wildlife is recommended apart from testing hunter-harvested animals with clinical signs or found-dead. Bats should be monitored as a natural host of many coronaviruses.

Species which may act as vectors or reservoirs of diseases covered by the Animal Health Law: Listed pathogens of molluscs.

Vector or reservoir species of five mollusc diseases 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. Mollusc species on or in which Mikrocytos mackini, Perkinsus marinus, Bonamia exitiosa, Bonamia ostreae and Marteilia refringens were detected, 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, this studied species was classified as a 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 molluscs was not found, these were defined as reservoir. 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 or reservoir mollusc species during transport was collected from scientific literature. It was concluded that it is very likely to almost certain (90-100%) that M. mackini, P. marinus, B. exitiosa B. ostreae and M. refringens 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 at aquaculture establishments or through contaminated water supply can possibly transmit these pathogens. For transmission of M. refringens, the presence of an intermediate host, a copepod, is necessary.

Species which may act as vectors or reservoirs of diseases covered by the Animal Health Law: Listed pathogens of crustaceans.

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.

Species which may act as vectors or reservoirs of diseases covered by the Animal Health Law: Listed pathogens of fish.

Vector or reservoir species of five fish diseases listed in the Animal Health Law were identified, based on evidence generated through an extensive literature review (ELR), to support a possible updating of Regulation (EU) 2018/1882. Fish species on or in which highly polymorphic region-deleted infectious salmon anaemia virus (HPR∆ ISAV), Koi herpes virus (KHV), epizootic haematopoietic necrosis virus (EHNV), infectious haematopoietic necrosis virus (IHNV) or viral haemorrhagic septicaemia virus (VHSV) were detected, 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 a 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 or 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 fish 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 or reservoir fish species during transport was collected from scientific literature. For VHSV, IHNV or HPR∆ ISAV, it was concluded that under transport conditions at temperatures below 25°C, it is likely (66-90%) they will remain infective. Therefore, vector or reservoir species that may have been exposed to these pathogens in an affected area in the wild, aquaculture establishments or through water supply can possibly transmit VHSV, IHNV or HPR∆ ISAV into a non-affected area when transported at a temperature below 25°C. The conclusion was the same for EHN and KHV; however, they are likely to remain infective under all transport temperatures.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) 2016/429): infection with Gyrodactylus salaris (GS).

Infection with Gyrodactylus salaris was assessed according to the criteria of the Animal Health Law (AHL), in particular, the criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as laid down in Article 9 and Article 8 for listing animal species related to infection with G. salaris. The assessment was performed following the ad hoc method for data collection and assessment previously developed by AHAW panel and already published. The outcome reported is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with an uncertain outcome. According to the assessment here performed, it is uncertain whether infection with G. salaris can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (33-70% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that Infection with G. salaris does not meet the criteria in Section 1 and 3 (Category A and C; 1-5% and 10-33% probability of fulfilling the criteria, respectively) and it is uncertain whether it meets the criteria in Sections 2, 4 and 5 (Categories B, D and E; 33-80%, 33-66% and 33-80% probability of meeting the criteria, respectively). The animal species to be listed for infection with G. salaris according to Article 8 criteria are provided.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) 2016/429): Bacterial kidney disease (BKD).

Bacterial kidney disease (BKD) was assessed according to the criteria of the Animal Health Law (AHL), in particular the criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as laid out in Article 9 and Article 8 for listing animal species related to BKD. The assessment was performed following the ad hoc method on data collection and assessment developed by AHAW Panel and already published. The outcome reported is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with an uncertain outcome. According to this assessment, BKD can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (66-90% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that BKD does not meet the criteria in Sections 1, 2 and 3 (Categories A, B and C; 1-5%, 33-66% and 33-66% probability of meeting the criteria, respectively) but meets the criteria in Sections 4 and 5 (Categories D and E; 66-90% and 66-90% probability of meeting the criteria, respectively). The animal species to be listed for BKD according to Article 8 criteria are provided.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU)2016/429): Infection with salmonid alphavirus (SAV).

Infection with salmonid alphavirus (SAV) was assessed according to the criteria of the Animal Health Law (AHL), in particular the criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as laid out in Article 9 and Article 8 for listing animal species related to infection with SAV. The assessment was performed following the ad hoc method on data collection and assessment developed by AHAW Panel and already published. The outcome reported is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with an uncertain outcome. According to the assessment, it was uncertain whether infection with salmonid alphavirus can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (50-80% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that infection with salmonid alphavirus does not meet the criteria in Section 1 (Category A; 5-10% probability of meeting the criteria) and it is uncertain whether it meets the criteria in Sections 2, 3, 4 and 5 (Categories B, C, D and E; 50-90%, probability of meeting the criteria). The animal species to be listed for infection with SAV according to Article 8 criteria are provided.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) 2016/429): Spring Viraemia of Carp (SVC).

Spring Viraemia of Carp (SVC) was assessed according to the criteria of the Animal Health Law (AHL), in particular the criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9 and Article 8 for listing animal species related to SVC. The assessment was performed following the ad hoc method for data collection and assessment previously developed by the AHAW panel and already published. The outcome reported is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with an uncertain outcome. According to the assessment performed here, it is uncertain whether SVC can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (45-90% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that SVC does not meet the criteria in Section 1 (Category A; 5-33% probability of meeting the criteria) and it is uncertain whether it meets the criteria in Sections 2, 3, 4 and 5 (Categories B, C, D and E; 33-66%, 10-66%, 45-90% and 45-90% probability of meeting the criteria, respectively). The animal species to be listed for SVC according to Article 8 criteria are provided.

Vaccination of poultry against highly pathogenic avian influenza - part 1. Available vaccines and vaccination strategies.

Several vaccines have been developed against highly pathogenic avian influenza (HPAI), mostly inactivated whole-virus vaccines for chickens. In the EU, one vaccine is authorised in chickens but is not fully efficacious to stop transmission, highlighting the need for vaccines tailored to diverse poultry species and production types. Off-label use of vaccines is possible, but effectiveness varies. Vaccines are usually injectable, a time-consuming process. Mass-application vaccines outside hatcheries remain rare. First vaccination varies from in-ovo to 6 weeks of age. Data about immunity onset and duration in the target species are often unavailable, despite being key for effective planning. Minimising antigenic distance between vaccines and field strains is essential, requiring rapid updates of vaccines to match circulating strains. Generating harmonised vaccine efficacy data showing vaccine ability to reduce transmission is crucial and this ability should be also assessed in field trials. Planning vaccination requires selecting the most adequate vaccine type and vaccination scheme. Emergency protective vaccination is limited to vaccines that are not restricted by species, age or pre-existing vector-immunity, while preventive vaccination should prioritise achieving the highest protection, especially for the most susceptible species in high-risk transmission areas. Model simulations in France, Italy and The Netherlands revealed that (i) duck and turkey farms are more infectious than chickens, (ii) depopulating infected farms only showed limitations in controlling disease spread, while 1-km ring-culling performed better than or similar to emergency preventive ring-vaccination scenarios, although with the highest number of depopulated farms, (iii) preventive vaccination of the most susceptible species in high-risk transmission areas was the best option to minimise the outbreaks' number and duration, (iv) during outbreaks in such areas, emergency protective vaccination in a 3-km radius was more effective than 1- and 10-km radius. Vaccine efficacy should be monitored and complement other surveillance and preventive efforts.

Welfare of broilers on farm.

This Scientific Opinion considers the welfare of domestic fowl (Gallus gallus) related to the production of meat (broilers) and includes the keeping of day-old chicks, broiler breeders, and broiler chickens. Currently used husbandry systems in the EU are described. Overall, 19 highly relevant welfare consequences (WCs) were identified based on severity, duration and frequency of occurrence: 'bone lesions', 'cold stress', 'gastro-enteric disorders', 'group stress', 'handling stress', 'heat stress', 'isolation stress', 'inability to perform comfort behaviour', 'inability to perform exploratory or foraging behaviour', 'inability to avoid unwanted sexual behaviour', 'locomotory disorders', 'prolonged hunger', 'prolonged thirst', 'predation stress', 'restriction of movement', 'resting problems', 'sensory under- and overstimulation', 'soft tissue and integument damage' and 'umbilical disorders'. These WCs and their animal-based measures (ABMs) that can identify them are described in detail. A variety of hazards related to the different husbandry systems were identified as well as ABMs for assessing the different WCs. Measures to prevent or correct the hazards and/or mitigate each of the WCs are listed. Recommendations are provided on quantitative or qualitative criteria to answer specific questions on the welfare of broilers and related to genetic selection, temperature, feed and water restriction, use of cages, light, air quality and mutilations in breeders such as beak trimming, de-toeing and comb dubbing. In addition, minimal requirements (e.g. stocking density, group size, nests, provision of litter, perches and platforms, drinkers and feeders, of covered veranda and outdoor range) for an enclosure for keeping broiler chickens (fast-growing, slower-growing and broiler breeders) are recommended. Finally, 'total mortality', 'wounds', 'carcass condemnation' and 'footpad dermatitis' are proposed as indicators for monitoring at slaughter the welfare of broilers on-farm.