RESUMEN

In September 2023, bluetongue virus serotype 3 (BTV-3) emerged in the Netherlands, infecting over five thousand livestock farms. In sheep, high morbidity and mortality rates were reported that were unlike previously described bluetongue outbreaks. This study aimed to quantify the impact of BTV-3 in the small ruminant population in the Netherlands in 2023. Sheep and goat movement census data and BTV-3 notification data were available from 2020 until the end of 2023. Data were aggregated to farm and week level and mortality indicators were calculated for lambs (<1 year) and adult animals (≥1 year). Population averaged GEE models with a Negative-binomial distribution and a log-link function correcting for repeated measures per farm in time were used to quantify the association between BTV-3 and mortality. In 2023, 2994 sheep farmers and 89 goat farmers notified clinical signs of BTV-3 to the NVWA. During this BTV-3 outbreak period, an additional 55,000 sheep died compared to the same period in 2020-2022. At flock level a high variety in mortality was observed, with a clear increase in mortality in both flocks that were not notified but that were located in infected areas and in flocks of which the farmer notified clinical signs. During the BTV-3 outbreak period, mortality in infected areas increased 4.2 (95 % CI: 4.0-4.3) times in sheep lambs (<1 year) and 4.6 (95 % CI: 4.4-4.8) times in sheep (≥1 year) compared to BTV-3 free areas. Flocks with a confirmed BTV-3 infection that were notified in September showed a 12.8 (95 % CI: 11.4-14.3) times higher mortality in lambs and a 15.1 (95 % CI: 13.7-16.6) times higher mortality in sheep compared to flocks in BTV-3 areas. In flocks of which the farmer notified clinical signs after September, mortality was 4.6 (95 % CI: 4.2-5.0) and 5.6 (95 % CI: 5.1-6.0) times higher in lambs and sheep compared BTV-3 areas respectively. In goats, around 4000 additional deaths were recorded during the BTV-3 outbreak period. In farms that were notified, mortality of goats (≥1 year) was 1.8 (95 % CI: 1.2-2.8) times higher compared to BTV-3 free areas. Since May 2024, multiple BTV-3 vaccines are available in the Netherlands. In June 2024, the first new infections of BTV-3 were confirmed in Dutch sheep flocks. Hopes are that with the possibility to vaccinate, the spread and impact of BTV-3 in the Netherlands will rapidly decline and that losses as observed in 2023 will no longer be seen.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Brotes de Enfermedades , Enfermedades de las Cabras , Cabras , Serogrupo , Animales , Lengua Azul/epidemiología , Lengua Azul/mortalidad , Lengua Azul/virología , Países Bajos/epidemiología , Ovinos , Brotes de Enfermedades/veterinaria , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/virología , Enfermedades de las Cabras/mortalidad , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/virología , Enfermedades de las Ovejas/mortalidad

RESUMEN

Agar gel immunodiffusion assay (AGID) is a laboratory test which detects specific antigen-antibody interactions by the development of visible precipitation lines in a semisolid matrix. Here we describe the preparation of agar gel plates, the method to test serum samples by AGID for the presence of EHDV antibodies, and the interpretation of test results. This test has known cross-reactivity to bluetongue antibodies; therefore positive samples by this assay require additional confirmatory testing; generally, its use should be limited to healthy animal attestations where required.

Asunto(s)

Inmunodifusión , Animales , Inmunodifusión/métodos , Virus de la Enfermedad Hemorrágica Epizoótica/inmunología , Agar/química , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Ovinos

RESUMEN

BACKGROUND: Culicoides midges have been well-studied in Spain, particularly over the last 20 years, mainly because of their role as vectors of arboviral diseases that affect livestock. Most studies on Culicoides are conducted using suction light traps in farmed environments, but studies employing alternative trapping techniques or focusing on natural habitats are scarce. METHODS: In the present study, we analyze Culicoides captured in 2023 at 476 sites in western Andalusia (southern Spain) using carbon dioxide-baited Biogents (BG)-sentinel traps across different ecosystems. RESULTS: We collected 3,084 Culicoides midges (3060 females and 24 males) belonging to 23 species, including the new species Culicoides grandifovea sp. nov. and the first record of Culicoides pseudolangeroni for Europe. Both species were described with morphological and molecular methods and detailed data on spatial distribution was also recorded. The new species showed close phylogenetic relations with sequences from an unidentified Culicoides from Morocco (92.6% similarity) and with Culicoides kurensis. Culicoides imicola was the most abundant species (17.4%), followed by Culicoides grandifovea sp. nov. (14.6%) and Culicoides kurensis (11.9%). Interestingly, Culicoides montanus was the only species of the obsoletus and pulicaris species complexes captured, representing the first record of this species in southern Spain. A total of 53 valid Culicoides species have been reported in the area, with 48 already reported in literature records and 5 more added in the present study. Information on the flight period for the most common Culicoides species is also provided. CONCLUSIONS: To the best of our knowledge, our study represents the most comprehensive effort ever done on nonfarmland habitats using carbon-dioxide baited suction traps for collecting Culicoides. Our data suggests that using carbon dioxide traps offers a completely different perspective on Culicoides communities compared with routinely used light traps, including the discovery of previously unrecorded species.

Asunto(s)

Ceratopogonidae , Filogenia , Ceratopogonidae/clasificación , Ceratopogonidae/genética , Animales , España , Femenino , Masculino , Insectos Vectores/clasificación , Ecosistema , Distribución Animal

RESUMEN

BACKGROUND: The bluetongue virus serotype 3 (BTV-3) outbreak in the Netherlands in 2023 caused severe clinical signs in ruminants. The clinical and pathological signs in ruminants and their spread during the outbreak in 2023 are described. METHODS: Data from the Dutch monitoring and surveillance system were available to describe clinical signs and pathological findings related to BTV-3 in sheep, cattle and goats. During the outbreak, 13 farms (five sheep, five cattle and three dairy goats) were closely monitored. RESULTS: In 2023, BTV-3 infections were confirmed by real-time polymerase chain reaction in sheep flocks (n = 1807), cattle herds (n = 1864), goat herds (n = 62), alpaca and/or llama herds (n = 15) and one dog. Sheep exhibited the most severe clinical signs and had the highest mortality. In other animal species, a large variation in both occurrence and severity of clinical signs was observed. LIMITATION: Only 13 farms were closely monitored. CONCLUSIONS: The clinical signs observed in affected animals during the 2023 BTV-3 outbreak seem to be more severe than those observed during the BTV-8 outbreak between 2006 and 2008. It seems likely that BTV-3 will overwinter, similar to BTV-8. Therefore, the availability of an effective and safe vaccine is crucial to limit the future impact of BTV-3.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Brotes de Enfermedades , Cabras , Serogrupo , Animales , Virus de la Lengua Azul/aislamiento & purificación , Lengua Azul/epidemiología , Lengua Azul/patología , Lengua Azul/virología , Países Bajos/epidemiología , Ovinos , Brotes de Enfermedades/veterinaria , Bovinos , Estudios Seroepidemiológicos , Rumiantes/virología , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/virología , Enfermedades de las Cabras/patología , Femenino , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Enfermedades de los Bovinos/patología

RESUMEN

Culicoides biting midge species (Diptera: Ceratopogonidae) of the Obsoletus Group and the Pulicaris Complex are considered the major vectors of bluetongue and Schmallenberg viruses in Europe. Overwintering strategies of these arboviruses are controversially discussed, with the ongoing activity of vector species and a non-disrupted transmission cycle during winter being a plausible explanation. Although data on Culicoides winter activity are relatively scant, a seasonal vector-free period (SVFP), during which adult Culicoides are not or hardly active, is questionable. To determine winter activity and define SVFPs according to the EU Commission Regulation No 1266/2007, adult Culicoides were trapped weekly with UV-light traps from October to April 2019/2020 and 2020/2021 inside and outside stables on 16 farms throughout Germany. Temperature measurements were taken regularly at each trapping site since the temperature is a known driver of biting midge activity. In 960 indoor and outdoor catches, 32,377 Culicoides were trapped, with 90.9% of them belonging to the Obsoletus Group, 6.1% to the Pulicaris Complex and 3.0% to 'other Culicoides' according to morphological identification. The majority (61.3%) of Culicoides were trapped indoors, with substantial numbers of specimens collected from October to December, in March and in April, and only a few or no specimens in January and February. Obsoletus Group biting midges were active indoors for almost the entire winter. Outdoors, Culicoides numbers decreased from October to December, few or no specimens were caught from January to March, and high numbers were captured in April. Of the collected Culicoides, 2028 were blood-fed, of which 94.6% were trapped in the stables. The indoor SVFP, although calculated for blood-fed instead of parous females, lasted for almost 4 months (late November until mid-March) in winter 2019/2020 and 2 months (January and February) in winter 2020/2021. The outdoor SVFPs covered almost the entire study period in both winters, with slight differences between the onsets and the ends. The Culicoides activity significantly depended on temperature. Specimens of the Obsoletus Group were caught at an average temperature of 7.4°C (minimum 0.3°C) and of the Pulicaris Complex at an average temperature of 10.3°C (minimum 1.2°C). These temperatures were reached inside the stables over more extended periods than outside. The average indoor temperatures were 1.2 K higher than the average outdoor temperatures, although absolute temperature differences of up to 9.0 K were recorded. Based on Culicoides activity, the results of the present study indicate an almost continuous potential for virus transmission in winter within livestock houses.

RESUMEN

The unenveloped Bluetongue virus capsid comprises several structural layers, the inner two comprising a core, which assembles before addition of the outer proteins, VP2 and VP5. Two symmetric trimers of VP5 fit like pegs into two distinct pits on the core and undergo pH conformational changes in the context of the virus, associated with cell entry. Here we show that in isolation VP5 alone undergoes essentially the same changes with pH and confirm a helical transition, indicating that VP5 is a motor during cell entry. In the absence of VP5 the two pits on the core differ from each other, presumably due to the asymmetric underlying structure of VP3, the innermost capsid protein. On insertion of VP5 these pits become closely similar and remain similar at low pH whilst VP5 is present. This natural asymmetry presumably destabilises the attachment of VP5, facilitating ejection upon low pH, membrane penetration and cell entry.

Asunto(s)

Virus de la Lengua Azul , Proteínas de la Cápside , Virus de la Lengua Azul/fisiología , Virus de la Lengua Azul/química , Concentración de Iones de Hidrógeno , Proteínas de la Cápside/química , Proteínas de la Cápside/metabolismo , Proteínas de la Cápside/genética , Internalización del Virus , Animales , Conformación Proteica

RESUMEN

Rift Valley fever virus (RVFV) causes disease outbreaks in livestock and humans; however, its inter-epidemic circulation is poorly understood, similar to other arboviruses affecting cattle such as bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). Serum samples were collected in Baringo County, Kenya from 400 cattle, accompanied by a risk factor questionnaire. Serological tests were then conducted to determine the exposure of cattle to RVFV, BTV, and EHDV. RVFV, BTV, and EHDV IgG seroprevalence rates were 15.5%, 91.5%, and 91%, respectively. Seropositivity for RVFV, BTV, and EHDV was significantly higher in adult cattle, as well as in females for RVFV. Cattle with herd owners aged between 30-39 years were less likely to be seropositive for RVFV compared to those with owners over the age of 60 years. High seroprevalence of BTV and EHDV in cattle indicates significant exposure and the subclinical circulation of these viruses, presenting a risk of outbreaks to sheep and naïve cattle. Moreover, the detection of RVFV-seropositive young cattle born after the last reported outbreak suggests inter-epidemic circulation of the virus. Overall, monitoring these arboviruses in cattle is crucial in understanding their distribution and seroprevalence during inter-epidemic periods.

RESUMEN

Bluetongue (BT) is a vector-borne disease affecting wild and domestic ruminants in many parts of the world. Although bluetongue virus (BTV) is widespread in ungulates in Africa, available epidemiological information on BT in this continent is limited. This systematic review and meta-analysis aimed to estimate the seroprevalence of BTV and summarize information on associated risk factors in domestic ruminants and camels in Africa. Systematic searches were conducted from the inception of the database to November 2022 on PubMed/MEDLINE, ScienceDirect, Web of Science, and Google/Google Scholar. Forty-four eligible publications were identified, published in the range from 1973 to 2020, and statistically analyzed. The pooled overall seroprevalence of BTV was 45.02% (95% confidence interval [CI]: 36.00-54.00%). The pooled seroprevalence was 49.70% (95% CI: 34.50-65.00%) in cattle, 47.00% (95% CI: 29.90-64.50%) in goats, 40.80% (95% CI: 19.60-63.90%) in camels, and 36.30% (95% CI: 29.00-44.90%) in sheep. The pooled seroprevalence decreased after 1990 and increased again after 2010. The highest pooled overall seroprevalence was found in the southeastern region, and the highest pooled overall seroprevalence was obtained by Competitive Enzyme-Linked Immunosorbent Assay. Finally, the seroprevalence in females (53.30%, 95% CI: 34.80-71.00%) was significantly higher than in males (28.10%, 95% CI: 17.40-40.30%) (p < 0.05). We showed that antibodies against BTV were common in African ruminants and camels. Monitoring the seroprevalence of BTV, as well as systematic and continuous surveillance of the Culicoides population, are encouraged to prevent and control the spread of BT.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Camelus , Enfermedades de los Bovinos , Enfermedades de las Cabras , Enfermedades de las Ovejas , Animales , Bovinos , África/epidemiología , Lengua Azul/epidemiología , Virus de la Lengua Azul/aislamiento & purificación , Camelus/virología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/virología , Cabras , Factores de Riesgo , Estudios Seroepidemiológicos , Ovinos , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/virología

RESUMEN

Bluetongue virus (BT) is a vector-borne virus that causes a disease, called bluetongue, which results in significant economic loss and morbidity in sheep, cattle, goats and wild ungulates across all continents of the world except Antarctica. Despite the geographical breadth of its impact, most BT epidemiological models are informed by parameters derived from the 2006-2009 BTV-8 European outbreak. The aim of this study was to develop a highly adaptable model for BT which could be used elsewhere in the world, as well as to identify the parameters which most influence outbreak dynamics, so that policy makers can be properly informed with the most current information to aid in disease planning. To provide a framework for future outbreak modelling and an updated parameterisation that reflects natural variation in infections, a newly developed and parameterised two-host, two-vector species ordinary differential equation model was formulated and analysed. The model was designed to be adaptable to be implemented in any region of the world and able to model both epidemic and endemic scenarios. It was parameterised using a systematic literature review of host-to-vector and vector-to-host transmission rates, host latent periods, host infectious periods, and vaccine protection factors. The model was demonstrated using the updated parameters, with South Africa as a setting based on the Western Cape's known cattle and sheep populations, local environmental parameters, and Culicoides spp. presence data. The sensitivity analysis identified that the duration of the infectious period for sheep and cows had the greatest impact on the outbreak length and number of animals infected at the peak of the outbreak. Transmission rates from cows and sheep to C. imicola midges greatly influenced the day on which the peak of the outbreak occurred, along with the duration of incubation period, and infectious period for cows. Finally, the protection factor of the vaccine had the greatest influence on the total number of animals infected. This knowledge could aid in the development of control measures. Due to gradual climate and anthropological change resulting in alterations in vector habitat suitability, BT outbreaks are likely to continue to increase in range and frequency. Therefore, this research provides an updated BT modelling framework for future outbreaks around the world to explore transmission, outbreak dynamics and control measures.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Enfermedades de los Bovinos , Brotes de Enfermedades , Animales , Lengua Azul/epidemiología , Lengua Azul/transmisión , Lengua Azul/virología , Lengua Azul/prevención & control , Ovinos , Bovinos , Brotes de Enfermedades/veterinaria , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Enfermedades de los Bovinos/transmisión , Ceratopogonidae/virología , Sudáfrica/epidemiología , Modelos Teóricos , Insectos Vectores/virología , Modelos Biológicos , Cabras

RESUMEN

Most mathematical models that assess the vectorial capacity of disease-transmitting insects typically focus on the influence of climatic factors to predict variations across different times and locations, or examine the impact of vector control interventions to forecast their potential effectiveness. We combine features of existing models to develop a novel model for vectorial capacity that considers both climate and vector control. This model considers how vector control tools affect vectors at each stage of their feeding cycle, and incorporates host availability and preference. Applying this model to arboviruses of veterinary importance in Europe, we show that African horse sickness virus (AHSV) has a higher peak predicted vectorial capacity than bluetongue virus (BTV), Schmallenberg virus (SBV), and epizootic haemorrhagic disease virus (EHDV). However, AHSV has a shorter average infectious period due to high mortality; therefore, the overall basic reproduction number of AHSV is similar to BTV. A comparable relationship exists between SBV and EHDV, with both viruses showing similar basic reproduction numbers. Focusing on AHSV transmission in the UK, insecticide-treated stable netting is shown to significantly reduce vectorial capacity of Culicoides, even at low coverage levels. However, untreated stable netting is likely to have limited impact. Overall, this model can be used to consider both climate and vector control interventions either currently utilised or for potential use in an outbreak, and could help guide policy makers seeking to mitigate the impact of climate change on disease control.

Asunto(s)

Infecciones por Arbovirus , Arbovirus , Ceratopogonidae , Clima , Insectos Vectores , Animales , Infecciones por Arbovirus/transmisión , Infecciones por Arbovirus/prevención & control , Arbovirus/fisiología , Insectos Vectores/virología , Insectos Vectores/fisiología , Ceratopogonidae/virología , Ceratopogonidae/fisiología , Modelos Teóricos , Europa (Continente)/epidemiología , Número Básico de Reproducción , Virus de la Lengua Azul/fisiología

RESUMEN

Europe faces regular introductions and reintroductions of bluetongue virus (BTV) serotypes, most recently exemplified by the incursion of serotype 3 in the Netherlands. Although the long-distance wind dispersal of the disease vector, Culicoides spp., is recognized as a virus introduction pathway, it remains understudied in risk assessments. A Quantitative Risk Assessment framework was developed to estimate the risk of BTV-3 incursion into mainland Europe from Sardinia, where the virus has been present since 2018. We used an atmospheric transport model (HYbrid Single-Particle Lagrangian Integrated Trajectory) to infer the probability of airborne dispersion of the insect vector. Epidemiological disease parameters quantified the virus prevalence in vector population in Sardinia and its potential first transmission after introduction in a new area. When assuming a 24h maximal flight duration, the risk of BTV introduction from Sardinia is limited to the Mediterranean Basin, mainly affecting the southwestern area of the Italian Peninsula, Sicily, Malta, and Corsica. The risk extends to the northern and central parts of Italy, Balearic archipelago, and mainland France and Spain, mostly when maximal flight duration is longer than 24h. Additional knowledge on vector flight conditions and Obsoletus complex-specific parameters could improve the robustness of the model. Providing both spatial and temporal insights into BTV introduction risks, our framework is a key tool to guide global surveillance and preparedness against epizootics.

RESUMEN

Introduction: Bluetongue (BT), caused by bluetongue virus (BTV), is an important arthropod-borne livestock disease listed by the World Organization for Animal Health. Live-attenuated and inactivated vaccines have permitted to control BT but they do not simultaneously protect against the myriad of BTV serotypes. Recently, we identified the highly conserved BTV nonstructural protein NS1 and the N-terminal region of NS2 as antigens capable of conferring multiserotype protection against BTV. Methods: Here, we designed Modified Vaccinia Ankara (MVA) viral vectors that expressed BTV-4 proteins VP2 or VP7 along with NS1 and NS2-Nt as well as MVAs that expressed proteins VP2, VP7 or NS1 and NS2-Nt. Results: Immunization of IFNAR(-/-) mice with two doses of MVA-NS1-2A-NS2-Nt protected mice from BTV-4M infection by the induction of an antigen-specific T cell immune response. Despite rMVA expressing VP7 alone were not protective in the IFNAR(-/-) mouse model, inclusion of VP7 in the vaccine formulation amplified the cell-mediated response induced by NS1 and NS2-Nt. Expression of VP2 elicited protective non-cross-reactive neutralizing antibodies (nAbs) in immunized animals and improved the protection observed in the MVA-NS1-2A-NS2-Nt immunized mice when these three BTV antigens were co-expressed. Moreover, vaccines candidates co-expressing VP2 or VP7 along with NS1 and NS2-Nt provided multiserotype protection. We assessed protective efficacy of both vaccine candidates in sheep against virulent challenge with BTV-4M. Discussion: Immunization with MVA-VP7-NS1-2A-NS2-Nt partially dumped viral replication and clinical disease whereas administration of MVA-VP2-NS1-2A-NS2-Nt promoted a complete protection, preventing viraemia and the pathology produced by BTV infection.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Proteínas de la Cápside , Vectores Genéticos , Receptor de Interferón alfa y beta , Virus Vaccinia , Proteínas no Estructurales Virales , Vacunas Virales , Animales , Virus de la Lengua Azul/inmunología , Virus de la Lengua Azul/genética , Proteínas no Estructurales Virales/inmunología , Proteínas no Estructurales Virales/genética , Lengua Azul/prevención & control , Lengua Azul/inmunología , Lengua Azul/virología , Ratones , Vacunas Virales/inmunología , Vacunas Virales/genética , Virus Vaccinia/genética , Virus Vaccinia/inmunología , Receptor de Interferón alfa y beta/genética , Proteínas de la Cápside/inmunología , Proteínas de la Cápside/genética , Ratones Noqueados , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Femenino

RESUMEN

Introduction: Bluetongue (BT) poses a significant threat to the livestock industry, affecting various animal species and resulting in substantial economic losses. The existence of numerous BT virus (BTV) serotypes has hindered control efforts, highlighting the need for broad-spectrum vaccines. Methodology: In this study, we evaluated the conserved amino acid sequences within key non-structural (NS) proteins of BTV and identified numerous highly conserved murine- and bovine-specific MHC class I-restricted (MHC-I) CD8+ and MHC-II-restricted CD4+ epitopes. We then screened these conserved epitopes for antigenicity, allergenicity, toxicity, and solubility. Using these epitopes, we developed in silico-based broad-spectrum multiepitope vaccines with Toll-like receptor (TLR-4) agonists. The predicted proinflammatory cytokine response was assessed in silico using the C-IMMSIM server. Structural modeling and refinement were achieved using Robetta and GalaxyWEB servers. Finally, we assessed the stability of the docking complexes through extensive 100-nanosecond molecular dynamics simulations before considering the vaccines for codon optimization and in silico cloning. Results: We found many epitopes that meet these criteria within NS1 and NS2 proteins and developed in silico broad-spectrum vaccines. The immune simulation studies revealed that these vaccines induce high levels of IFN-γ and IL-2 in the vaccinated groups. Protein-protein docking analysis demonstrated promising epitopes with strong binding affinities to TLR-4. The docked complexes were stable, with minimal Root Mean Square Deviation and Root Mean Square Fluctuation values. Finally, the in silico-cloned plasmids have high % of GC content with > 0.8 codon adaptation index, suggesting they are suitable for expressing the protein vaccines in prokaryotic system. Discussion: These next-generation vaccine designs are promising and warrant further investigation in wet lab experiments to assess their immunogenicity, safety, and efficacy for practical application in livestock. Our findings offer a robust framework for developing a comprehensive, broad-spectrum vaccine, potentially revolutionizing BT control and prevention strategies in the livestock industry.

Asunto(s)

Virus de la Lengua Azul , Biología Computacional , Epítopos de Linfocito T , Proteínas no Estructurales Virales , Vacunas Virales , Animales , Virus de la Lengua Azul/inmunología , Epítopos de Linfocito T/inmunología , Vacunas Virales/inmunología , Proteínas no Estructurales Virales/inmunología , Proteínas no Estructurales Virales/genética , Ratones , Biología Computacional/métodos , Serogrupo , Bovinos , Lengua Azul/prevención & control , Lengua Azul/inmunología , Lengua Azul/virología , Secuencia Conservada

RESUMEN

Bluetongue disease is an infectious disease transmitted by Culicoides as vectors, mainly infecting ruminants. Because ruminants play an important role in animal husbandry in China, the outbreak of bluetongue disease can cause serious economic losses. Maxent model was applied to predict the distribution of bluetongue in China based on the data derived from domestic and foreign academic literature databases including CNKI, Wanfang Database, PubMed, Web of Science and Google Scholar. The results showed that annual mean temperature (BIO1), precipitation in driest month (BIO14), sheep density (SD) and altitude (Elev) were the relevant variables of bioclimatic suitable zones for bluetongue disease. Precipitation in wettest month (BIO13), BIO1, BIO14, Elev were the main variables affecting the habitat of the bluetongue vector Culicoides. The most suitable climate for bluetongue infection occurs in southern China, central China and parts of Xinjiang. The suitable living areas of Culicoides are mainly located in southern, central and eastern China, and the overlap of the two suitable areas is high. The study suggested that southern, central, and eastern China are high-risk areas for bluetongue due to the significant overlap of suitable habitats for both the disease and its vector. Implementing effective surveillance and targeted control strategies in these regions is crucial for mitigating the impact of bluetongue disease.

Asunto(s)

Lengua Azul , Ceratopogonidae , Lengua Azul/transmisión , Lengua Azul/epidemiología , Animales , China/epidemiología , Ceratopogonidae/virología , Ovinos , Insectos Vectores/virología , Virus de la Lengua Azul/fisiología , Clima

RESUMEN

The serological surveillance of bluetongue in bulk tank milk is an efficient and cost-effective method for the early detection of bluetongue virus incursions in unvaccinated free areas of the disease. In addition, the availability of standardized and reliable reagents and refined diagnostic procedures with high sensitivity and specificity are essential for surveillance purposes. However, no available reference materials for bluetongue virus serological surveillance in bulk tank milk exist. This study shows the production and characterization of reference material for the implementation of a commercially available bluetongue milk ELISA test in official laboratories, as well as the evaluation of a procedure to increase the sensitivity in samples with low levels of antibodies. This procedure, based on milk protein concentration, allowed us to notably increase the ELISA test's analytical sensitivity, which is useful for milk samples from farms with low within-herd prevalence or pools of bulk tank milk samples. The standardized milk reference material produced here, together with the evaluated procedure to improve analytical sensitivity, could be applied as tools to ensure an accurate diagnosis by official laboratories in bluetongue unvaccinated free areas.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Ensayo de Inmunoadsorción Enzimática , Proteínas de la Leche , Leche , Sensibilidad y Especificidad , Animales , Leche/virología , Leche/química , Lengua Azul/diagnóstico , Lengua Azul/virología , Virus de la Lengua Azul/inmunología , Virus de la Lengua Azul/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática/métodos , Ovinos , Bovinos , Proteínas de la Leche/análisis , Proteínas de la Leche/inmunología , Anticuerpos Antivirales/sangre , Pruebas Serológicas/métodos , Pruebas Serológicas/normas , Estándares de Referencia , Femenino

RESUMEN

Since 1998, notifiable bluetongue virus (BTV) serotypes 1-4, 6, 8, 9, 11, and 16 have been reported in Europe. In August 2006, a bluetongue (BT) outbreak caused by BTV serotype 8 began in northwestern Europe. The Netherlands was declared BT-free in February 2012, and annual monitoring continued. On September 3, 2023, typical BT clinical manifestations in sheep were notified to the Netherlands Food and Product Safety Consumer Authority. On September 6, we confirmed BTV infection through laboratory diagnosis; notifications of clinical signs in cattle were also reported. We determined the virus was serotype 3 by whole-genome sequencing. Retrospective analysis did not reveal BTV circulation earlier than September. The virus source and introduction route into the Netherlands remains unknown. Continuous monitoring and molecular diagnostic testing of livestock will be needed to determine virus spread, and new prevention strategies will be required to prevent BTV circulation within the Netherlands and Europe.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Serogrupo , Virus de la Lengua Azul/clasificación , Virus de la Lengua Azul/genética , Virus de la Lengua Azul/aislamiento & purificación , Lengua Azul/epidemiología , Lengua Azul/virología , Animales , Países Bajos/epidemiología , Ovinos , Bovinos , Brotes de Enfermedades , Filogenia , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/virología , Historia del Siglo XXI , Estudios Retrospectivos

RESUMEN

Epizootic hemorrhagic disease (EHD), caused by Epizootic hemorrhagic disease virus (EHDV), is an emerging and severe livestock disease. Recent incursion and distribution of EHDV in Europe have outlined the emerging character of EHD. Despite its worldwide impact, numerous knowledge gaps exist. A range of inconveniences restricts utilization of natural hosts of EHDV. Here, we show that adult mice deficient in type I IFN receptor (IFNAR(-/-)) are highly susceptible to EHDV-6 and EHDV-8 infection when the virus is administered subcutaneously. Disease was characterized by ruffled hair, reluctance to move, dehydration and conjunctivitis, with viraemia detected from day 5 post-infection. A deeper characterization of EHDV-8 infection showed viral replication in the lung, liver, spleen, kidney, testis and ovaries. Importantly, increased expression levels of pro-inflammatory cytokines IL-1ß, IL-6 and CXCL2 were observed in spleen after EHDV-8 infection. Furthermore, IFNAR(-/-) adult mice immunized with a EHDV-8 inactivated vaccine elicited neutralizing antibodies specific of EHDV-8 and full protection against challenge with a lethal dose of this virus. This study also explores the possibilities of this animal model for study of BTV and EHDV coinfection. In summary, the IFNAR(-/-) mouse model faithfully recapitulates EHD and can be applied for vaccine testing, which can facilitate progress in addressing the animal health challenge posed by this virus.

Asunto(s)

Modelos Animales de Enfermedad , Virus de la Enfermedad Hemorrágica Epizoótica , Receptor de Interferón alfa y beta , Vacunas Virales , Animales , Ratones , Receptor de Interferón alfa y beta/genética , Receptor de Interferón alfa y beta/metabolismo , Virus de la Enfermedad Hemorrágica Epizoótica/inmunología , Virus de la Enfermedad Hemorrágica Epizoótica/genética , Vacunas Virales/inmunología , Infecciones por Reoviridae/inmunología , Femenino , Ratones Noqueados , Anticuerpos Neutralizantes/inmunología , Masculino

RESUMEN

This study investigated the sero-epidemiology of bluetongue in ruminants in North-Western Pakistan. A total of 3,173 serum samples were collected from small (n = 1,651) and large (n = 1,522) ruminants being reared by farmers in 14 districts. Antibodies to bluetongue virus (BTV) were detected using competitive ELISA. The overall prevalence of BTV antibodies was 65%. A significant association (P < 0.05) between the prevalence of BTV antibodies and the risk factors including sex, species, age, area, husbandry practices and breed was shown by univariate analysis. In multivariate analysis, the seroprevalence was 6.5 (95% CL = 3.7-11.4), 5.9 (95% CL = 3.8-9.4) and 2.4 (95% CL = 1.5-3.7) times higher in buffaloes, cattle and goats than sheep, respectively. The seroprevalence was 1.4 (95% CL = 1.1-1.7) times higher in local breeds than in cross/exotic breeds. The seroprevalence was 1.6 (95% CL = 1.1 to 2.3) times higher in sedentary animals than in nomadic animals. The seroprevalence was significantly associated with age. Further work is required to determine the BTV serotypes prevalent in the study area for effective control of the disease.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Enfermedades de las Cabras , Animales , Pakistán/epidemiología , Estudios Seroepidemiológicos , Lengua Azul/epidemiología , Lengua Azul/virología , Virus de la Lengua Azul/inmunología , Femenino , Masculino , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/virología , Ovinos , Cabras , Bovinos , Anticuerpos Antivirales/sangre , Rumiantes/virología , Factores de Riesgo , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Crianza de Animales Domésticos , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/virología , Prevalencia

RESUMEN

In October 2023, bluetongue virus serotype 3 (BTV-3) emerged in Germany, where Schmallenberg virus is enzootic. We detected BTV-3 in 1 pool of Culicoides biting midges collected at the time ruminant infections were reported. Schmallenberg virus was found in many vector pools. Vector trapping and analysis could elucidate viral spread.

Asunto(s)

Virus de la Lengua Azul , Lengua Azul , Infecciones por Bunyaviridae , Ceratopogonidae , Insectos Vectores , Orthobunyavirus , Serogrupo , Animales , Ceratopogonidae/virología , Ceratopogonidae/clasificación , Virus de la Lengua Azul/clasificación , Virus de la Lengua Azul/aislamiento & purificación , Alemania/epidemiología , Orthobunyavirus/clasificación , Orthobunyavirus/genética , Orthobunyavirus/aislamiento & purificación , Lengua Azul/virología , Lengua Azul/epidemiología , Lengua Azul/transmisión , Infecciones por Bunyaviridae/veterinaria , Infecciones por Bunyaviridae/virología , Infecciones por Bunyaviridae/transmisión , Infecciones por Bunyaviridae/epidemiología , Insectos Vectores/virología

RESUMEN

Hemorrhagic disease (HD) of deer is caused by epizootic hemorrhagic disease virus (EHDV) or bluetongue virus (BTV) and is considered one of the most important viral diseases of white-tailed deer (Odocoileus virginianus). Despite evidence of changing patterns of HD in the northeastern and upper midwestern US, the historical and current patterns of HD in the Great Plains remain poorly described. We used results from an annual survey documenting HD mortality to characterize historic and current patterns of HD in the northern and central Great Plains (North Dakota, South Dakota, Nebraska, Kansas, and Oklahoma), US, between 1982 and 2020. Further, we assessed temporal change using linear regression to determine change in annual reporting intensity (percentage of counties in a state with reported HD) and change in reporting frequency (the number of years a county or state reported HD) during each decade between 1982 and 2020. Across the 38-yr study period, HD reports expanded northeast across latitude and longitude. Intensity of HD reports significantly increased during this period for three (North Dakota, South Dakota, Kansas) of five states examined. Frequency of reports also increased for all five states. Such changes in northern latitudes might lead to increased deer mortality in regions where HD epizootics have been historically less frequent. Understanding how patterns of HD are changing on the landscape is important when considering future deer management in the face of other mortality factors.

Asunto(s)

Ciervos , Virus de la Enfermedad Hemorrágica Epizoótica , Infecciones por Reoviridae , Animales , Ciervos/virología , Infecciones por Reoviridae/veterinaria , Infecciones por Reoviridae/epidemiología , Infecciones por Reoviridae/mortalidad , North Dakota/epidemiología , South Dakota/epidemiología