RESUMO
IMPORTANCE: Lumpy skin disease virus (LSDV) has a complex epidemiology involving multiple strains, recombination, and vaccination. Its DNA genome provides limited genetic variation to trace outbreaks in space and time. Sequencing of LSDV whole genomes has also been patchy at global and regional scales. Here, we provide the first fine-grained whole genome sequence sampling of a constrained LSDV outbreak (southeastern Europe, 2015-2017), which we analyze along with global publicly available genomes. We formally evaluate the past occurrence of recombination events as well as the temporal signal that is required for calibrating molecular clock models and subsequently conduct a time-calibrated spatially explicit phylogeographic reconstruction. Our study further illustrates the importance of accounting for recombination events before reconstructing global and regional dynamics of DNA viruses. More LSDV whole genomes from endemic areas are needed to obtain a comprehensive understanding of global LSDV dispersal dynamics.
Assuntos
Genoma Viral , Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Animais , Bovinos , Surtos de Doenças , DNA Viral/genética , Europa (Continente)/epidemiologia , Doença Nodular Cutânea/epidemiologia , Doença Nodular Cutânea/virologia , Vírus da Doença Nodular Cutânea/genética , FilogeniaRESUMO
Lumpy skin disease (LSD) is a transboundary disease of economic importance affecting cattle and buffaloes. In South-Eastern Europe, immunization of cattle with homologous live attenuated vaccines for LSD control has prevented outbreaks since 2017, but has been associated with adverse reactions resembling disease symptoms. Thus, a diagnostic method suitable for disease surveillance in farms during vaccination campaigns with Neethling (Onderstepoort) and SIS type (Lumpyvax) live attenuated LSDV vaccines in Europe should be able to detect the wild type (WT) LSDV in animals with adverse reactions to the vaccines and samples with potentially high titers of the vaccine LSDV. To this end, a real-time PCR method targeting the EEV gene of LSDV was developed for the specific detection of WT strains, along with the use of beta-actin gene as an internal amplification control (IAC). Amplification efficiency of the WT virus target was 99.0% and 98.6%, in the presence and in the absence of high loads of vaccine LSDV, respectively. In the presence of 105.6 vaccine LSDV DNA copies, the limit of detection for WT LSDV was 12.6 DNA copies per reaction. The inter-assay CV was 0.04% for WT LSDV and 0.13% for beta-actin. The method can confirm diagnosis in suspect cases irrespective of the presence of the vaccine LSDV DNA by overcoming the masking effect of the WT LSDV. The simultaneous amplification of the beta-actin gene further assures the quality of diagnostic testing. The new method is a surveillance tool, complementing the DIVA real-time PCR during vaccination campaigns and can provide rapid insight on the targeted EEV gene in countries with novel and recombinant LSDV strains.
Assuntos
Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Actinas/genética , Animais , Bovinos , Doença Nodular Cutânea/diagnóstico , Doença Nodular Cutânea/prevenção & controle , Vírus da Doença Nodular Cutânea/genética , Reação em Cadeia da Polimerase em Tempo Real , Vacinas AtenuadasRESUMO
Lumpy skin disease is a high-consequence disease in cattle caused by infection with the poxvirus lumpy skin disease virus (LSDV). The virus is endemic in most countries in Africa and an emerging threat to cattle populations in Europe and Asia. As LSDV spreads into new regions, it is important that signs of disease are recognized promptly by animal caregivers. This study describes the gross, microscopic, and ultrastructural changes that occur over time in cattle experimentally challenged with LSDV. Four calves were inoculated with wildtype LSDV and monitored for 19 to 21 days. At 7 days after inoculation, 2 of the 4 cattle developed multifocal cutaneous nodules characteristic of LSD. Some lesions displayed a targetoid appearance. Histologically, intercellular and intracellular edema was present in the epidermis of some nodules. Occasional intracytoplasmic inclusion bodies were identified in keratinocytes. More severe and consistent changes were present in the dermis, with marked histiocytic inflammation and necrotizing fibrinoid vasculitis of dermal vessels, particularly the deep dermal plexus. Chronic lesions consisted of full-thickness necrosis of the dermis and epidermis. Lesions in other body organs were not a major feature of LSD in this study, highlighting the strong cutaneous tropism of this virus. Immunohistochemistry and electron microscopy identified LSDV-infected histiocytes and fibroblasts in the skin nodules of affected cattle. This study highlights the noteworthy lesions of LSDV and how they develop over time.
Assuntos
Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea/isolamento & purificação , Animais , Ásia/epidemiologia , Bovinos , Doenças dos Bovinos/virologia , Doenças Transmissíveis Emergentes/veterinária , Doenças Transmissíveis Emergentes/virologia , Dermatite/patologia , Dermatite/veterinária , Dermatite/virologia , Doenças Endêmicas/veterinária , Europa (Continente)/epidemiologia , Doença Nodular Cutânea/epidemiologia , Doença Nodular Cutânea/patologia , Doença Nodular Cutânea/transmissão , Doença Nodular Cutânea/virologia , Vírus da Doença Nodular Cutânea/patogenicidade , Vírus da Doença Nodular Cutânea/ultraestrutura , Pele/patologia , Pele/virologia , Vasculite/patologia , Vasculite/veterinária , Vasculite/virologiaRESUMO
Bluetongue virus (BTV) is endemic in many parts of the world, often causing severe hemorrhagic disease in livestock. To date, at least 27 different serotypes have been recognized. Vaccination against all serotypes is necessary to protect susceptible animals and to prevent onward spread of the virus by insect vectors. In our previous studies, we generated replication-deficient (disabled infectious single-cycle [DISC]) virus strains for a number of serotypes and reported preliminary data on their protective efficacy in animals. In this report, to advance the DISC vaccines to the marketplace, we investigated different parameters of these DISC vaccines. First, we demonstrated the genetic stabilities of these vaccine strains and also the complementing cell line. Subsequently, the optimal storage conditions of vaccines, including additives, temperature, and desiccation, were determined and their protective efficacies in animals confirmed. Furthermore, to test if mixtures of different vaccine strains could be tolerated, we tested cocktails of DISC vaccines in combinations of three or six different serotypes in sheep and cattle, the two natural hosts of BTV. Groups of sheep vaccinated with a cocktail of six different vaccines were completely protected from challenge with individual virulent serotypes, both in early challenge and after 5 months of challenge without any clinical disease. There was no interference in protection between the different vaccines. Protection was also achieved in cattle with a mixture of three vaccine strains, albeit at a lesser level than in sheep. Our data support and validate the suitability of these virus strains as the next-generation vaccines for BTV. IMPORTANCE: Bluetongue (BT) is a debilitating and in many cases lethal disease that affects ruminants of economic importance. Classical vaccines that afford protection against bluetongue virus, the etiological agent, are not free from secondary and undesirable effects. A surge in new approaches to produce highly attenuated, safer vaccines was evident after the development of the BTV reverse-genetics system that allows the introduction of targeted mutations in the virus genome. We targeted an essential gene to develop disabled virus strains as vaccine candidates. The results presented in this report further substantiate our previous evidence and support the suitability of these virus strains as the next-generation BTV vaccines.
Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Vírus Bluetongue/efeitos dos fármacos , Bluetongue/prevenção & controle , Vacinas Virais/imunologia , Vírion/imunologia , Animais , Sequência de Bases , Bluetongue/imunologia , Bluetongue/virologia , Vírus Bluetongue/classificação , Vírus Bluetongue/genética , Vírus Bluetongue/imunologia , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Bovinos , Linhagem Celular , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Feminino , Masculino , Genética Reversa , Sorogrupo , Ovinos , Vacinação , Vacinas Atenuadas , Vacinas de Subunidades Antigênicas , Vacinas Virais/administração & dosagem , Vacinas Virais/biossíntese , Vacinas Virais/genética , Vírion/genéticaRESUMO
Since 1998, 9 of the 26 serotypes of bluetongue virus (BTV) have spread throughout Europe, and serotype 8 has suddenly emerged in northern Europe, causing considerable economic losses, direct (mortality and morbidity) but also indirect, due to restriction in animal movements. Therefore, many new types of vaccines, particularly subunit vaccines, with improved safety and efficacy for a broad range of BTV serotypes are currently being developed by different laboratories. Here we exploited a reverse genetics-based replication-deficient BTV serotype 1 (BTV-1) (disabled infectious single cycle [DISC]) strain to generate a series of DISC vaccine strains. Cattle and sheep were vaccinated with these viruses either singly or in cocktail form as a multivalent vaccine candidate. All vaccinated animals were seroconverted and developed neutralizing antibody responses to their respective serotypes. After challenge with the virulent strains at 21 days postvaccination, vaccinated animals showed neither any clinical reaction nor viremia. Further, there was no interference with protection with a multivalent preparation of six distinct DISC viruses. These data indicate that a very-rapid-response vaccine could be developed based on which serotypes are circulating in the population at the time of an outbreak.
Assuntos
Vírus Bluetongue/imunologia , Bluetongue/prevenção & controle , Doenças dos Bovinos/prevenção & controle , Vacinas Virais/isolamento & purificação , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Bluetongue/epidemiologia , Bluetongue/imunologia , Vírus Bluetongue/classificação , Vírus Bluetongue/genética , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/imunologia , Surtos de Doenças/prevenção & controle , Surtos de Doenças/veterinária , Europa (Continente)/epidemiologia , Feminino , RNA Viral/genética , Vírus Reordenados/genética , Vírus Reordenados/imunologia , Sorotipagem , Carneiro Doméstico , Vacinas de Subunidades Antigênicas/isolamento & purificação , Replicação Viral/genéticaRESUMO
In September 2022, more than 50 years after its eradication from Spain, Sheep pox virus was confirmed by laboratory analysis in sheep showing characteristic lesions. This was the start of an outbreak that lasted 9 months and infected 30 farms dispersed over two different areas, Andalusia and Castilla-La Mancha. Early after the initial confirmation, an active surveillance based on clinical inspection with laboratory confirmation of sheep with clinical signs was started in restricted areas. This allowed the confirmation of Sheep pox in 22 out of 28 suspected farms, where limited numbers of sheep with mainly erythema and papules were found, indicative of early detection. Nevertheless, to improve active surveillance and stop the outbreak, clinical inspection was reinforced by laboratory analysis in all inspected farms, even when no clinically diseased sheep were detected. Although more than 35,000 oral swabs from 335 farms were analysed by real-time PCR in pools of five, only two out of six reported outbreaks in this period were detected by laboratory analysis before clinical signs were observed. Furthermore, additional insights were gained from the extensive laboratory surveillance performed on samples collected under field conditions. No evidence of Sheep pox virus infection was found in goats. Oral swabs proved to be the sample of choice for early detection in the absence of scabs and could be tested in pools of five without extensive loss in sensitivity; serology by ELISA was not useful in outbreak detection. Finally, a non-infectious genome of the virus could be detected months after cleaning and disinfection; thus, real-time PCR results should be interpreted with caution in sentinel animals during repopulation. In conclusion, the outbreak of Sheep pox virus in Spain showed that active clinical inspection with laboratory confirmation of clinically diseased sheep via oral swab testing proved a sensitive method for detection of infected farms, providing insights in laboratory surveillance that will be helpful for other countries confronted with Sheep pox outbreaks.
Assuntos
Capripoxvirus , Surtos de Doenças , Infecções por Poxviridae , Doenças dos Ovinos , Animais , Espanha/epidemiologia , Surtos de Doenças/veterinária , Ovinos , Infecções por Poxviridae/veterinária , Infecções por Poxviridae/epidemiologia , Infecções por Poxviridae/diagnóstico , Infecções por Poxviridae/virologia , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/virologia , Doenças dos Ovinos/diagnóstico , Capripoxvirus/genética , Capripoxvirus/isolamento & purificação , Cabras , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Fazendas , Monitoramento Epidemiológico/veterináriaRESUMO
Lumpy Skin Disease virus is a poxvirus from the genus Capripox that mainly affects bovines and it causes severe economic losses to livestock holders. The Lumpy Skin Disease virus is currently dispersing in Asia, but little is known about detailed phylogenetic relations between the strains and genome evolution. We reconstructed a whole-genome-sequence (WGS)-based phylogeny and compared it with single-gene-based phylogenies. To study population and spatiotemporal patterns in greater detail, we reconstructed networks. We determined that there are strains from multiple clades within the previously defined cluster 1.2 that correspond with recorded outbreaks across Eurasia and South Asia (Indian subcontinent), while strains from cluster 2.5 spread in Southeast Asia. We concluded that using only a single gene (cheap, fast and easy to routinely use) for sequencing lacks phylogenetic and spatiotemporal resolution and we recommend to create at least one WGS whenever possible. We also found that there are three gene regions, highly variable, across the genome of LSDV. These gene regions are located in the 5' and 3' flanking regions of the LSDV genome and they encode genes that are involved in immune evasion strategies of the virus. These may provide a starting point to further investigate the evolution of the virus.
Assuntos
Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Humanos , Bovinos , Animais , Vírus da Doença Nodular Cutânea/genética , Doença Nodular Cutânea/epidemiologia , Filogenia , Genômica , Surtos de Doenças , Evolução MolecularRESUMO
The current epidemic in Asia, driven by LSDV recombinants, poses difficulties to existing DIVA PCR tests, as these do not differentiate between homologous vaccine strains and the recombinant strains. We, therefore, developed and validated a new duplex real-time PCR capable of differentiating Neethling-based vaccine strains from classical and recombinant wild-type strains that are currently circulating in Asia. The DIVA potential of this new assay, seen in the in silico evaluation, was confirmed on samples from LSDV infected and vaccinated animals and on isolates of LSDV recombinants (n = 12), vaccine (n = 5), and classic wild-type strains (n = 6). No cross-reactivity or a-specificity with other capripox viruses was observed under field conditions in non-capripox viral stocks and negative animals. The high analytical sensitivity is translated into a high diagnostic specificity as more than 70 samples were all correctly detected with Ct values very similar to those of a published first-line pan capripox real-time PCR. Finally, the low inter- and intra-run variability observed shows that the new DIVA PCR is very robust which facilitates its implementation in the lab. All validation parameters that are mentioned above indicate the potential of the newly developed test as a promising diagnostic tool which could help to control the current LSDV epidemic in Asia.
Assuntos
Capripoxvirus , Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Vacinas Virais , Animais , Bovinos , Vírus da Doença Nodular Cutânea/genética , Reação em Cadeia da Polimerase em Tempo Real , Doença Nodular Cutânea/diagnóstico , Doença Nodular Cutânea/prevenção & controle , Vacinas Virais/genética , Vacinas Atenuadas , Capripoxvirus/genéticaRESUMO
Lumpy skin disease virus (LSDV) is a vector-transmitted capripox virus that causes disease in cattle. Stomoxys calcitrans flies are considered to be important vectors as they are able to transmit viruses from cattle with the typical LSDV skin nodules to naive cattle. No conclusive data are, however, available concerning the role of subclinically or preclinically infected cattle in virus transmission. Therefore, an in vivo transmission study with 13 donors, experimentally inoculated with LSDV, and 13 naïve acceptor bulls was performed whereby S. calcitrans flies were fed on either subclinical- or preclinical-infected donor animals. Transmission of LSDV from subclinical donors showing proof of productive virus replication but without formation of skin nodules was demonstrated in two out of five acceptor animals, while no transmission was seen from preclinical donors that developed nodules after Stomoxys calcitrans flies had fed. Interestingly, one of the acceptor animals which became infected developed a subclinical form of the disease. Our results show that subclinical animals can contribute to virus transmission. Therefore, stamping out only clinically diseased LSDV-infected cattle could be insufficient to completely halt the spread and control of the disease.
Assuntos
Capripoxvirus , Doenças dos Bovinos , Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Muscidae , Bovinos , Animais , Masculino , Insetos VetoresRESUMO
Vaccines have proven themselves as an efficient way to control and eradicate lumpy skin disease (LSD). In addition to the safety and efficacy aspects, it is important to know the duration for which the vaccines confer protective immunity, as this impacts the design of an efficient control and eradication program. We evaluated the duration of immunity induced by a live attenuated vaccine (LSDV LAV) and an inactivated vaccine (LSDV Inac), both based on LSDV. Cattle were vaccinated and challenged after 6, 12 and 18 months for LSDV LAV or after 6 and 12 months for the LSDV Inac. The LSDV LAV elicited a strong immune response and protection for up to 18 months, as no clinical signs or viremia could be observed after a viral LSDV challenge in any of the vaccinated animals. A good immune response and protection were similarly seen for the LSDV Inac after 6 months. However, two animals developed clinical signs and viremia when challenged after 12 months. In conclusion, our data support the annual booster vaccination when using the live attenuated vaccine, as recommended by the manufacturer, which could potentially even be prolonged. In contrast, a bi-annual vaccination seems necessary when using the inactivated vaccine.
RESUMO
The diseases caused by capripoxviruses (CaPVs) are of major economic concern in sheep, goat and cattle as they are inexorably spreading into non-endemic regions. As CaPV strains are serologically indistinguishable and genetically highly homologous, typing closely related strains can only be achieved by whole genome sequencing. Unfortunately the number of publicly available genomes remains low as most sequencing methods rely on virus isolation. Therefore, we developed a robust, cost-effective and widely applicable method that allows to generate (nearly) complete CaPV genomes directly from clinical samples or commercial vaccine batches. A set of pan-CaPVs long-range PCRs spanning the entire genome was designed to generate PCR amplicons that can be sequenced on commonly used high-throughput sequencing platforms: MiSeq (Illumina), RSII (PacBio) and MinION (Oxford Nanopore Technologies). The robustness of the LR-PCR strategy was evaluated for all 3 members of CaPV directly from a variety of samples, including clinical samples (N = 7), vaccine batches (N = 6), and virus isolates (N = 2). The sequencing method described here allows to reconstruct (nearly) complete CaPV genomes in less than a week and will aid researchers studying closely-related CaPV strains worldwide.
Assuntos
Capripoxvirus , Doenças dos Ovinos , Animais , Capripoxvirus/genética , Bovinos , Análise Custo-Benefício , Sequenciamento de Nucleotídeos em Larga Escala , Ovinos , Sequenciamento Completo do GenomaRESUMO
From 2017 to 2019, several vaccine-like recombinant strains of lumpy skin disease virus (LSDV) were discovered in Kazakhstan and neighbouring regions of Russia and China. Shortly before their emergence, the authorities in Kazakhstan launched a mass vaccination campaign with the Neethling-based Lumpivax vaccine. Since none of the other countries in the affected region had used a homologous LSDV vaccine, it was soon suspected that the Lumpivax vaccine was the cause of these unusual LSDV strains. In this study, we performed a genome-wide molecular analysis to investigate the composition of two Lumpivax vaccine batches and to establish a possible link between the vaccine and the recent outbreaks. Although labelled as a pure Neethling-based LSDV vaccine, the Lumpivax vaccine appears to be a complex mixture of multiple CaPVs. Using an iterative enrichment/assembly strategy, we obtained the complete genomes of a Neethling-like LSDV vaccine strain, a KSGP-like LSDV vaccine strain and a Sudan-like GTPV strain. The same analysis also revealed the presence of several recombinant LSDV strains that were (almost) identical to the recently described vaccine-like LSDV strains. Based on their InDel/SNP signatures, the vaccine-like recombinant strains can be divided into four groups. Each group has a distinct breakpoint pattern resulting from multiple recombination events, with the number of genetic exchanges ranging from 126 to 146. The enormous divergence of the recombinant strains suggests that they arose during seed production. The recent emergence of vaccine-like LSDV strains in large parts of Asia is, therefore, most likely the result of a spillover from animals vaccinated with the Lumpivax vaccine.
Assuntos
Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Vacinas Virais , Animais , Ásia/epidemiologia , Bovinos , Vacinas Atenuadas , Vacinas Virais/genéticaRESUMO
From 1975 to 2021, the United Arab Emirates (UAE) imported more than 1300 live Arabian oryxes (AOs) and scimitar-horned oryxes (SHOs) for conservation programs. The objective of this study was to estimate the prevalence of orbiviruses Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) in AOs and SHOs from captive herds in the UAE. Between October 2014 and April 2015, 16 AOs and 13 SHOs originating from Texas (USA) and 195 out of about 4000 SHOs from two locations in the UAE were blood sampled to be tested by indirect enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcriptase polymerase chain reaction (RT-qPCR) assays. Eight imported AOs (50% CI [24.7-75.4%]) and eight imported SHOs (61.5% CI [31.6-86.1%]) were found BTV seropositive, in contrast with three out of 195 SHOs (1.5% CI [0.3-4.4%]) from the Emirates. BTV-2 genome was detected in 6/16 of the Arabian Oryx, and amongst those, one out of six was seronegative. None of the tested samples was found positive for EHDV. Our results illustrate the wide local variation regarding BTV seroprevalence in domestic and wild ruminants in the Arabian Peninsula. These results stress the need for pre-import risk assessment when considering translocation of wild ruminant species susceptible to orbiviruses not only in the country of destination but also where transit happens.
RESUMO
Burundi is a small, densely populated country in the African Great Lakes region. In March 2016, several hundreds of cattle were reported with vesicular lesions, suggesting foot-and-mouth disease (FMD). Epithelial samples, saliva, and blood were collected in six of the affected provinces spread over the country. The overall seroprevalence of FMD virus (FMDV) in the affected herds, as determined by antibodies against FMDV non-structural proteins, was estimated at 87%. Antibodies against FMDV serotypes O (52%), A (44%), C (19%), SAT1 (36%), SAT2 (58%), and SAT3 (23%) were detected across the provinces. FMDV genome was detected in samples from five of the six provinces using rRT-PCR. FMDV was isolated from samples from three provinces: in Cibitoke province, serotypes A and SAT2 were isolated, while in Mwaro and Rutana provinces, only serotype SAT2 was isolated. In Bururi and Cankuzo provinces, the serological profile suggested a recent incursion with serotype SAT2, while in Bubanza province, the serological profile suggested past incursions with serotype O and possibly serotype SAT1. The phylogenetic assessments showed the presence of topotypes A/Africa/G-I and SAT2/IV, similarly to previously characterized virus strains from other countries in the region, suggesting a transboundary origin and necessitating a regional approach for vaccination and control of FMD.
Assuntos
Doenças dos Bovinos , Vírus da Febre Aftosa , Febre Aftosa , África Oriental/epidemiologia , Animais , Burundi/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Surtos de Doenças/veterinária , Febre Aftosa/epidemiologia , Filogenia , Estudos Soroepidemiológicos , SorogrupoRESUMO
Foot-and-mouth disease (FMD) affects the livestock industry and socioeconomic sustainability of many African countries. The success of FMD control programs in Africa depends largely on understanding the dynamics of FMD virus (FMDV) spread. In light of the recent outbreaks of FMD that affected the North-Western African countries in 2018 and 2019, we investigated the evolutionary phylodynamics of the causative serotype O viral strains all belonging to the East-Africa 3 topotype (O/EA-3). We analyzed a total of 489 sequences encoding the FMDV VP1 genome region generated from samples collected from 25 African and Western Asian countries between 1974 and 2019. Using Bayesian evolutionary models on genomic and epidemiological data, we inferred the routes of introduction and migration of the FMDV O/EA-3 topotype at the inter-regional scale. We inferred a mean substitution rate of 6.64 × 10-3 nt/site/year and we predicted that the most recent common ancestor for our panel of samples circulated between February 1967 and November 1973 in Yemen, likely reflecting the epidemiological situation in under sampled cattle-exporting East African countries. Our study also reinforces the role previously described of Sudan and South Sudan as a frequent source of FMDVs spread. In particular, we identified two transboundary routes of O/EA-3 diffusion: the first from Sudan to North-East Africa, and from the latter into Israel and Palestine AT; a second from Sudan to Nigeria, Cameroon, and from there to further into West and North-West Africa. This study highlights the necessity to reinforce surveillance at an inter-regional scale in Africa and Western Asia, in particular along the identified migration routes for the implementation of efficient control measures in the fight against FMD.
Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Animais , Teorema de Bayes , Bovinos , Surtos de Doenças/veterinária , Febre Aftosa/epidemiologia , Vírus da Febre Aftosa/genética , Nigéria/epidemiologia , Filogenia , SorogrupoRESUMO
Lumpy skin disease (LSD) diagnosis is primarily based on clinical surveillance complemented by PCR of lesion crusts or nodule biopsies. Since LSD can be subclinical, the sensitivity of clinical surveillance could be lower than expected. Furthermore, real-time PCR for the detection of LSD viral DNA in blood samples from subclinical animals is only intermittently positive. Therefore, this study aimed to investigate an acceptable, easily applicable and more sensitive testing method for the detection of clinical and subclinical LSD. An animal experiment was conducted to investigate ear notches and biopsies from unaffected skin taken from the neck and dorsal back as alternatives to blood samples. It was concluded that for early LSD confirmation, normal skin biopsies and ear notches are less fit for purpose, as LSDV DNA is only detectable in these samples several days after it is detectable in blood samples. On the other hand, blood samples are less advisable for the detection of subclinical animals, while ear notches and biopsies were positive for LSD viral DNA in all subclinically infected animals by 16 days post infection. In conclusion, ear notches could be used for surveillance to detect subclinical animals after removing the clinical animals from a herd, to regain trade by substantiating the freedom of disease or to support research on LSDV transmission from subclinical animals.
RESUMO
Vaccines form the cornerstone of any control, eradication and preventative strategy and this is no different for lumpy skin disease. However, the usefulness of a vaccine is determined by a multiplicity of factors which include stability, efficiency, safety and ease of use, to name a few. Although the vaccination campaign in the Balkans against lumpy skin disease virus (LSDV) was successful and has been implemented with success in the past in other countries, data of vaccine failure have also been reported. It was therefore the purpose of this study to compare five homologous live attenuated LSDV vaccines (LSDV LAV) in a standardized setting. All five LSDV LAVs studied were able to protect against a challenge with virulent LSDV. Aside from small differences in serological responses, important differences were seen in side effects such as a local reaction and a Neethling response upon vaccination between the analyzed vaccines. These observations can have important implications in the applicability in the field for some of these LSDV LAVs.
RESUMO
Bluetongue is one of the major diseases of ruminants listed by the World Organisation for Animal Health. Bluetongue virus serotype 8 (BTV-8) has been considered enzootic in France since 2018. Here, we report the nearly complete genome sequences of two BTV-8 isolates from the 2020 outbreak in the Grand Duchy of Luxembourg.
RESUMO
Vaccination is an effective approach to prevent, control and eradicate diseases, including lumpy skin disease (LSD). One of the measures to address farmer hesitation to vaccinate is guaranteeing the quality of vaccine batches. The purpose of this study was to demonstrate the importance of a quality procedure via the evaluation of the LSD vaccine, Lumpivax (Kevevapi). The initial PCR screening revealed the presence of wild type LSD virus (LSDV) and goatpox virus (GTPV), in addition to vaccine LSDV. New phylogenetic PCRs were developed to characterize in detail the genomic content and a vaccination/challenge trial was conducted to evaluate the impact on efficacy and diagnostics. The characterization confirmed the presence of LSDV wild-, vaccine- and GTPV-like sequences in the vaccine vial and also in samples taken from the vaccinated animals. The analysis was also suggestive for the presence of GTPV-LSDV (vaccine/wild) recombinants. In addition, the LSDV status of some of the animal samples was greatly influenced by the differentiating real-PCR used and could result in misinterpretation. Although the vaccine was clinically protective, the viral genomic content of the vaccine (being it multiple Capripox viruses and/or recombinants) and the impact on the diagnostics casts serious doubts of its use in the field.
RESUMO
Lumpy skin disease virus (LSDV) causes a severe, systemic, and economically important disease in cattle. Here, we report coding-complete sequences of recombinant LSDVs from four outbreaks in October and November 2020 in northeastern Vietnam.