Lumpy skin disease (LSD) outbreaks in cattle in Odisha state, India in August 2019: Epidemiological features and molecular studies

Poxvirus pathology and pathogenesis in agriculturally important species

Zoonotic poxviruses, including monkeypox virus (MPV), the causative agent for Mpox disease, have gained significant media and scientific attention due to recent outbreaks in human populations across the globe. The increase in human cases of poxvirus infection is not unexpected, as routine vaccination against smallpox (a disease caused by the poxvirus variola virus, which cross protects against other orthopoxviruses) was discontinued in the 1980s after its eradication. Large numbers of vertebrate and invertebrate species are susceptible to infection by Poxviridae. Clinical signs and histologic lesions caused by genetically different poxviruses can be strikingly similar with some notable exceptions (eg, poxviral infections in fish). The purpose of this article is to review poxvirus pathology and pathogenesis observed in species of agricultural significance including poultry, cattle, goats, sheep, camels, swine, rabbits, horses, salmon, and carp.

Assessment of economic burden of lumpy skin disease in India using stochastic modeling

This study assessed the farm-level economic loss due to LSD in India and at disaggregate (state) level by collecting data from 2351 cattle farms covering seven states. Data were analyed using descriptive statistics and stochastic modeling with Monte Carlo simulations. Gujarat state reported the highest milk loss, with a median reduction of 74, 90, 60, 45, 15, 15, and 8 L per animal in Rajasthan, Gujarat, Tamil Nadu, Karnataka, Madhya Pradesh, Assam, and Odisha, respectively. Crossbred cattle experienced more milk loss per animal, ranging from USD 0.0 to 237.8. The median mortality loss per animal varied between USD 12.2 and 1,084. The substantial national loss was due to decreased milk production, followed by the loss of draught power, treatment cost, and vector management cost. Stochastic modelling estimated economic loss due to LSD in cattle in India was USD 2440.29 million (90% CI 2162.55-2716.15) / (INR 202,544.07 million (90% 179,491.65-2,225,440.45) during 2022 & 2023 with a highest loss of USD 314.18 million (90% CI 279.10-349.34)) in Rajasthan state.

Mathematical model of the lumpy skin disease using Caputo fractional-order derivative via invariant point technique

The aim of this paper is to study the fractional model of Lumpy Skin Disease, aiming to enhance our understanding of this disease. Specifically, we employ the recently introduced Caputo-Fabrizio fractional (CFF) derivative to analyze the Lumpy Skin Disease model in detail. To comprehensively study the model's solutions, we utilize the Picard-Lindelof approach to assess their existence and uniqueness. Furthermore, we employ numerical techniques, specifically the CFF derivative combined with the fundamental theorem of fractional calculus and fixed point theorem, to obtain the solutions of Lumpy Skin Disease in near form using fractional order. This innovative approach offers novel insights into the dynamics of the disease model that were previously unexplored. In addition, numerical simulations are conducted to explore the change in effects of control parameters on specific compartments within the model. The geometric representation of the model provides valuable insights into its complexity and reliability. By simulating each model compartment at various fractional orders and comparing them with integer-order simulations, we highlight the effectiveness of modern derivatives. Overall, our fractional analysis emphasizes the enhanced accuracy of non-integer order derivatives in capturing the dynamics of the Lumpy Skin Disease model. These findings contribute to advancing our understanding of the disease and may have implications for its control and management strategies.

Genetic characterization of lumpy skin disease virus (LSDV) isolates from an outbreak on Great Nicobar Island, India, in 2022 reveals the involvement of a cluster 2.5 recombinant LSDV strain (East/Southeast Asian lineage)

Lumpy skin disease (LSD) has emerged as a global threat to cattle health and production. Although India has been encountering regular episodes of LSD epidemics on the mainland since 2019, the Andaman and Nicobar Islands remained free of LSD until 2021. In this study, we investigated the first LSD outbreak on Great Nicobar Island in 2022 and examined the genetic characteristics of the LSDV strain associated with this outbreak. The morbidity and mortality rates in cattle were 38.29% and 1.89%, respectively. We screened 123 samples (whole blood, nasal swab, or skin tissue) from 111 cattle by LSDV real-time PCR and sera from 86 cattle by LSDV antibody ELISA, and the results confirmed LSDV infection. Subsequent nucleotide sequencing and phylogenetic analysis of five selected marker genes (GPCR, RPO30, P32, EEV, and B22R) revealed that the LSDV strain from Great Nicobar Island resembled cluster 2.5 LSDV recombinant strains from East and Southeast Asia but was distinct from wild-type LSDV strains (1.2.1, 1.2.2) circulating in mainland India, indicating an exotic source of introduction. Phylogenetic analysis using a concatenated sequence (GPCR-RPO30-P32-EEV-B22R) showed that both the wild-type and recombinant LSDV strains formed well-supported clusters, indicating that this type of analysis may be used as an alternative to whole-genome sequence analysis. We also found that determination of the nucleotide sequence of the C-terminal 717 bp of the B22R gene may be sufficient for reliable assignment of circulating LSDV isolates to a particular cluster. This is the first report of the detection of a recombinant LSDV strain in India, demonstrating the spread of cluster 2.5 recombinant LSDV further into South Asia. Our findings highlight the value of LSDV surveillance and genetic analysis for LSDV epidemiology, which may be helpful for developing effective control strategies.

Development of a Multi-Locus Real-Time PCR with a High-Resolution Melting Assay to Differentiate Wild-Type, Asian Recombinant, and Vaccine Strains of Lumpy Skin Disease Virus

Lumpy skin disease virus (LSDV) affects cattle and causes significant economic damage. The live vaccine derived from an attenuated strain is effective but is associated with mild disease and skin lesions in some vaccinated cattle. Moreover, recombinant LSDV strains, particularly one with wild-type field and vaccine strains, have recently emerged and spread throughout Asian countries. A cost-effective LSDV typing method is required. We developed a multi-locus real-time PCR with a high-resolution melting (HRM) assay to differentiate between the wild-type, vaccine, and dominant Asian recombinant strains. Based on a multiple alignment analysis, we selected three target genes for the HRM assay, ORF095, ORF126, and ORF145, in which there are insertions/deletions and nucleotide substitutions between wild-type and vaccine strains, and designed primer sets for the assay. Using the synthetic DNA encoding these genes for the two strains, it was shown that the PCR amplicons intercalated with a saturating fluorescent dye could clearly differentiate between wild-type and vaccine strains in the HRM analysis for all three target genes. Further, using clinical samples, our method was able to identify recombinant strains harboring the wild-type ORF095 and ORF145 and the vaccine strain ORF126 genes. Thus, our HRM assay may provide rapid LSDV typing.

Molecular Detection, Seroprevalence and Biochemical Analysis of Lumpy Skin Disease Virus

Lumpy skin disease (LSD) is a transboundary viral disease caused by lumpy skin disease virus (LSDV), belonging to the Capripoxvirus genus and Poxviridae family. This study reports on the molecular detection, seroprevalence and biochemical analysis of samples from cattle infected with LSDV in Madhya Pradesh (MP) and Telangana. A total of 189 samples (116 blood, 26 tissue, 47 nasal swabs) were collected from MP during 2022-2023. Molecular detection was performed using conventional PCR targeting the P32 and fusion genes, while seroprevalence was assessed using an indirect ELISA kit on 184 serum samples collected from MP and Telangana between 2022 and 2024. Tissue samples showed a higher positivity rate (69.23%) for the P32 gene, while nasal swabs had a 6.38% positivity rate. The fusion gene was detected in 77.77% of tissue and 66.66% of nasal swab samples. The seroprevalence study revealed that 19.56% of serum samples were positive, with a higher prevalence of 86.11% in MP. Biochemical analysis indicated elevated levels of SGPT, SGOT, BUN, creatinine, albumin, globulin and the A/G ratio in LSDV-infected cattle, though these differences were not statistically significant. The study emphasizes that blood samples are not ideal for LSDV detection and the timing of serum sample collection plays a critical role in seroprevalence studies.

Investigation of Comorbidity and Risk Factors Analysis During Lumpy Skin Disease Outbreaks in India

Lumpy skin disease (LSD) is a re-emerging viral transboundary disease affecting cattle and buffaloes, resulting in a significant socio-economic impact on the affected regions. LSD is primarily transmitted among susceptible livestock through hematophagous vectors, including ticks and flies. Ticks also function as reservoirs for various haemoprotozoan parasites, increasing the likelihood of coinfections in affected animals. This study investigates the comorbidity of LSD and associated risk factors using diverse datasets. A total of 414 samples from LSD-suspected animals were screened for LSD, infectious bovine rhinotracheitis (IBR), malignant catarrhal fever (MCF), babesiosis, and theileriosis (Theileria annulata and Theileria orientalis), as well as anaplasmosis. Among these, 214 (51.6%) tested positive for LSD. A strong correlation was identified between LSD and oriental theileriosis caused by Theileria orientalis (50.9%). Other significant associations were observed with IBR (34.1%), anaplasmosis (24.7%), tropical theileriosis (15.4%), babesiosis (12.6%), and MCF (12.1%). The transmission dynamics of LSD revealed that hematophagous vectors, particularly Stomoxys, Haematobia, and Rhipicephalus, play a crucial role in its spread, especially in unorganised farming systems. Additionally, Haematobia and Stomoxys flies were implicated in the high transmission rate of oriental theileriosis (39%) in conjunction with LSD. Notably, ticks (Rhipicephalus) facilitated the concurrent transmission of one, two, or three infections alongside LSD. While Musca, a non-hematophagous fly, was found to carry LSD virus (LSDV), it did not test positive for other pathogens. This study highlights the potential for cattle to harbour multiple diseases simultaneously with LSD, emphasising the necessity for integrated transmission studies and comprehensive disease screening in affected livestock. These findings underscore the importance of implementing targeted prevention and control strategies to mitigate disease impact in livestock populations.

Differentially Expressed miRNA Profiles in Serum-Derived Exosomes from Cattle Infected with Lumpy Skin Disease Virus

Exosomal miRNAs from individual cells are crucial in regulating the immune response to infectious diseases. In this study, we performed small RNA sequencing (small RNA-seq) analysis to identify the expressed and associated exosomal miRNAs in the serum of cattle infected with lumpy skin disease virus (LSDV). Cattle were infected with a 106.5 TCID50/mL LSDV Vietnam/HaTinh/CX01 (HT10) strain and exosomal miRNA expression in the serum of infected cattle was analyzed using small RNA sequencing (small RNA-seq). We identified 59 differentially expressed (DE) miRNAs in LSDV-infected cattle compared to uninfected controls, including 18 upregulated and 41 downregulated miRNAs. These 59 miRNAs were used to predict 7656 target genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the target genes were enriched in several biological processes and pathways associated with viral replication, immune response, virus-host interactions, and signal transduction. Additionally, we identified 708 potentially novel cattle miRNAs corresponding to 710 genomic loci. The transcription levels of five miRNA genes (bta-miR-11985, bta-miR-1281, bta-miR-12034, bta-miR-let-7i, and bta-miR-17-5p) were validated using reverse transcription quantitative real-time PCR, showing consistency with the small RNA-seq results. Overall, these findings provide significant insights into the immune and protective responses during LSDV infection in cattle, offering valuable information on identifying new biomarkers and understanding the pathogenesis of LSDV.

Molecular characterization of lumpy skin disease virus during the first outbreak of lumpy skin disease in Northern Himalayas, India

Lumpy skin disease (LSD) is a highly contagious and fatal transboundary viral disease of cattle and water buffaloes caused by the Lumpy Skin Disease virus (LSDV) which belongs to the genus Capripoxvirus of the Poxviridae family. The disease causes huge economic impact and has been listed as a notifiable disease by World Organization for Animal Health. We present the molecular epidemiology of an LSD outbreak, the first-ever outbreak of the disease in the Union Territory (UT) of Jammu and Kashmir, India; a region lying in Northern Himalayas. During the outbreak, 1661 samples were collected from clinically affected, in-contact cattle as well as apparently healthy animals and screened for LSDV by qPCR. From these 1661 samples, 643 (38.7%) were found positive. Five LSDV-positive samples were randomly selected and the GPCR gene was amplified, cloned and sequenced. A 12-nucleotide deletion was observed in the GPCR gene when compared to the 2019 Indian LSDV isolate from Odhisa, India. Based on the data obtained by qPCR analysis, the occurrence of LSD was determined with respect to the age, sex and breed of the animals. Furthermore, ticks collected from the affected animals and flies on the farm were identified and were found positive for LSDV.

Lumpy skin disease: a systematic review of mode of transmission, risk of emergence, and risk entry pathways

Lumpy skin disease (LSD), a viral disease of cattle, can be acute, subacute, or inactive. It is distinguished by fever and the abrupt emergence of firm, confined cutaneous nodules that usually necrotize. Similar lesions may occur in the skeletal muscles and the mucosae of the digestive and respiratory tracts. It is an enzootic, rapidly explorative, and sometimes fatal infection, characterized by multiple raised nodules on the skin of infected animals. LSDV has a large genome, it is employed as a vaccine carrier, generating a new complex with other viral genes by homologous recombination. This review summarizes our current knowledge of lumpy skin disease (LSD), its impact on animal health, host-pathogen interaction, etiology, signs or symptoms, prevention, and treatment strategies.

Distinct amino acid substitutions in the EEV glycoprotein and DNA-dependent RNA polymerase of lumpy skin disease virus identified in wetland areas of Bangladesh

The recent outbreak of lumpy skin disease virus (LSDV) in the wetland areas of Bangladesh presents a significant concern for both animal health and regional biosecurity. Epidemiological investigations into nine major outbreaks in the wetland areas revealed distinctive clinical symptoms in affected cattle, including elevated body temperature, excessive salivation, and the presence of skin nodules. Histopathological examination unveiled larger nodules compared to previous outbreaks, along with signs of secondary infection. Molecular analysis confirmed the presence of LSDV in all samples, with subsequent sequencing revealing genetic similarities with virus isolates of Bangladesh, India, China, Russia, Serbia and Greece. Most importantly amino acid variations in the viral EEV glycoprotein and DNA-dependent RNA polymerase were revealed that also altered the structures of the respective proteins significantly suggesting potential implications for viral pathogenesis. Additionally, successful isolation of LSDV in Vero cells demonstrated cytopathic effects, supporting the potential for vaccine development. In conclusion, this study provides comprehensive insights into the epidemiology, genomic characters with altered predicted structures of two major viral proteins and pathogenesis of LSDV outbreaks in Bangladesh. These findings emphasize the critical need for ongoing monitoring and adaptive control strategies, including the development of effective vaccines, to mitigate the impact of LSDV in affected regions and safeguard regional livestock health.

Molecular epidemiology and phylogenetic insights of lumpy skin disease in cattle from diverse agro-ecological regions of Punjab, Pakistan

Lumpy skin disease (LSD) is an emerging, highly contagious transboundary disease of bovines caused by the Lumpy skin disease virus (LSDV), responsible for substantial economic losses to the dairy, meat, and leather industries in Pakistan as well as various countries around the world. Epidemiological information on LSD is scarce in Punjab, Pakistan. Therefore, a molecular epidemiological study was conducted in two agro-ecologically diverse districts (Bhakkar and Jhang) of Punjab, Pakistan. A total of 800 blood samples were randomly collected from the jugular vein of clinically suspected cattle with nodular lesions using a multistage cluster sampling technique. The sampling unit was indigenous, crossbred, and exotic breeds of cattle. Four hundred samples were collected from each district. Ten union councils (UC) were selected from each district, and two villages were selected from each union council. From each village, twenty cattle were selected for sample collection. The PCR-based overall prevalence of LSDV in clinically suspected cattle using the P32 gene was 36.25% (36.25%; 290/800). The multivariable logistic regression analysis indicated that animals who were not treated with acaricide (P = 0.014; OR = 1.459; C.I = 1.079-1.972), body condition score (emaciated animals; P = 0.019; OR = 1.573; CI = 1.076-2.301), and gender (female; (P = 0.016; OR = 1.435; CI = 1.072-1.969) were significantly at higher risk for LSDV infection in cattle. The phylogenetic insights revealed that our isolates were linked to Kenya, China, Russia, Egypt, India, Zimbabwe, Iraq, and Iran. It can be concluded that LSD is widely distributed in the study area, with evidence of genetic diversity. Further studies are required on genetic composition using variable genetic markers for effective control and eradication of LSDV in Pakistan.

Isolation and Identification of Lumpy Skin Disease Virus

Lumpy skin disease virus (LSDV), a member of the capripoxvirus genus, induces lumpy skin disease (LSD) in cattle and buffalo populations. The initial documentation of LSD dates back to 1929 in Zambia, with subsequent rapid dissemination within the cattle community in Africa and Asia. Described as the "smallpox" equivalent in cattle, LSD manifests through clinical features such as fever, extensive cutaneous nodules, body wasting, lymph node enlargement, and skin edema. Isolation of LSDV constitutes an important step in evaluating virulence and implementing disease control measures. Skin samples obtained from afflicted cattle serve as the primary source for LSDV isolation due to its tropism for epidermal cells. Other tissues, including blood, lung, spleen, and saliva samples, are also employed for viral isolation. This chapter presents protocols for the convenient isolation of LSDV, relying on the plaque formation phenotype and utilizing MDBK cells. Emphasis is placed on stringent quality control methodologies to identify isolated viruses through multiple techniques, facilitating further investigations such as the in vitro growth of isolated LSDV.

Evidence of natural lumpy skin disease virus (LSDV) infection and genetic characterization of LSDV strains from water buffaloes (Bubalus bubalis) in India

Lumpy skin disease (LSD) has emerged as a threat to cattle production in Asia, and India has been facing LSD epidemics since 2019. Although water buffalo (Bubalus bubalis) is susceptible to natural LSDV infection, there have been no confirmed reports of LSDV infection in water buffalo in India. In this study, we investigated suspected cases of LSD in water buffaloes from 12 Indian states and one union territory during 2020-2023. Buffaloes showed mild to moderate clinical disease with fever and nodular skin lesions, but most remained asymptomatic. Eighteen of 177 (10.18%) buffaloes in 12 districts in three states tested positive for LSDV by real-time PCR, while 22 of 57 (38.59%) from nine districts in six states tested positive for LSDV-neutralizing antibodies, demonstrating the prevalence of LSDV infection in buffaloes over a wider geographic area. Successful virus isolation and nucleotide sequencing confirmed natural LSDV infection in buffaloes. Phylogenetic analysis of complete GPCR, RPO30, and EEV gene sequences revealed the presence of wild-type strains of two divergent LSDV lineages (1.2.1 and 1.2.2) in buffaloes. The 1.2.2 strains were closely related to the dominant LSDV strain (subcluster 1.2.2, KSGP-like) circulating in India, while the 1.2.1 strains clustered with strains from the Middle East, Europe, and the Balkans, confirming that there have been multiple introductions of LSDV into India. The detection of viruses with identical sequences in buffaloes and local cattle implied that the LSDV strain found in buffaloes is probably of cattle origin. We also found evidence of cocirculation of LSDV 1.2.1 and 1.2.2 wild-type strains in the same area, highlighting the importance of LSDV surveillance and genetic analysis. This is the first confirmed report of natural LSDV infection in water buffaloes in India. Further investigations are needed to assess the impact of LSDV infection in buffalo production and the role of buffalo in LSD epidemiology.

Pathological, immunological and molecular epidemiological analysis of lumpy skin disease virus in Indian cattle during a high-mortality epidemic

Lumpy skin disease (LSD) is an economically significant, emerging viral disease of Cattle and Buffaloes. This study aimed to investigate the causes of high mortality in a recent LSD epidemic in India. We examined 1618 animals across seventy outbreaks and conducted post-mortem on 48 cattle out of 513 clinically suspected LSD cases. The morbidity, mortality and case fatality rates recorded were 31.70%, 2.97 and 9.37% respectively. Disease stages were categorized as early (20.81%), mid (42.02%), and late (37.17%) and the distribution of skin lesions was classified as mild (34.14%), moderate (39.39%), and severe (26.47%). Post-mortem findings revealed systemic infection with necrotic and ulcerative nodules on multiple internal organs. Histologically, necrotizing vasculitis and mononuclear cell infiltration with intracytoplasmic inclusions were observed in various organs. The highest viral load was found in skin nodules/scabs, trachea, tongue, and lymph nodes. The viral load was significantly higher in mid- and late-stages of skin nodules and internal organs; whereas, blood from early-stage showed high viral load. The expression of Th1-type and Th2-type cytokines varied significantly across different stages of the disease. The downregulation of the apoptotic intrinsic and upregulation of the extrinsic pathway genes, suggesting that the latter plays a role in LSDV infection. Genetic analysis revealed that the LSD virus (LSDV) isolates were derived from a Kenyan ancestral strain with unique nucleotide changes in RPO30 and P32 gene. In conclusion, the high mortality in the recent Indian LSD epidemic can be attributed to a newly identified, highly virulent strain of LSDV causing systemic infection.

Prediction of lumpy skin disease virus using customized CBAM-DenseNet-attention model

Lumpy skin disease virus (LSDV) is an extremely infectious, viral, and chronic skin disease that is caused by the Capripox virus. This viral disease is predominantly found in cows. Mosquitoes and ticks are the primary transmitters for the spread of this virus. Recently, LSDV has been rapidly spreading all over the world, especially in several areas of Pakistan, India, and Iran. Thousands of cows have died due to this infectious virus in Pakistan and early detection of LSDV is needed to avoid further loss. The prediction and classification of LSDV are hindered by the lack of publicly available datasets. Despite a few studies using LSDV datasets, such datasets are often small, which may lead to model overfitting. In this regard, we collect the dataset from several online sources, as well as, collecting images from veterinary farms in different areas of Pakistan. Deep learning has been widely used in the medical field for disease detection and classification. Therefore, this study leverages DenseNet deep learning models for LSDV detection and classification. Experiments are performed using VGG-16, ResNet-50, MobileNet-V2, custom-designed convolutional neural network, and Inception-V3. The DenseNet architecture presents a Convolutional Block Attention Module (CBAM) and Spatial Attention (SA) for the prediction and classification of LSD. Results demonstrate that a 99.11% accuracy can be obtained on the augmented dataset while a 94.23% accuracy can be achieved with the original dataset for chicken pox, monkey pox, and LSDV. Comparison with state-of-the-art studies corroborates the superior performance of the proposed model.

A systematic review of epidemiological modelling in response to lumpy skin disease outbreaks

Lumpy skin disease (LSD) is an infectious disease currently spreading worldwide and poses a serious global threat. However, there is limited evidence and understanding to support the use of models to inform decision-making in LSD outbreak responses. This review aimed to identify modelling approaches that can be used before and during an outbreak of LSD, examining their characteristics and priorities, and proposing a structured workflow. We conducted a systematic review and identified 60 relevant publications on LSD outbreak modelling. The review identified six categories of question to be addressed following outbreak detection (origin, entry pathway, outbreak severity, risk factors, spread, and effectiveness of control measures), and five analytical techniques used to address them (descriptive epidemiology, risk factor analysis, spatiotemporal analysis, dynamic transmission modelling, and simulation modelling). We evaluated the questions each analytical technique can address, along with their data requirements and limitations, and accordingly assigned priorities to the modelling. Based on this, we propose a structured workflow for modelling during an LSD outbreak. Additionally, we emphasise the importance of pre-outbreak preparation and continuous updating of modelling post-outbreak for effective decision-making. This study also discusses the inherent limitations and uncertainties in the identified modelling approaches. To support this workflow, high-quality data must be collected in standardised formats, and efforts should be made to reduce inherent uncertainties of the models. The suggested modelling workflow can be used as a process to support rapid response for countries facing their first LSD occurrence and can be adapted to other transboundary diseases.

The expanding host range of lumpy skin disease virus in wild and domestic animals

Clinical lumpy skin disease (LSD) predominantly affects cattle and, to lesser extent domestic water buffalos. Whilst earlier work focussed on the disease in Africa, the recent emergence of LSD virus (LSDV) as a major cause of disease in Asia has led to a widening range of susceptible hosts for the virus. This article lists the wild and domestic ungulates in which LSDV infection has been confirmed and considers the significance of the disease for these species in Asia.

Design and assessment of a double antigen indirect ELISA for lumpy skin disease surveillance in India

Lumpy skin disease (LSD), caused by the lumpy skin disease virus of the genus Capripoxvirus, is rapidly emerging across most countries in Asia. Recently, LSD has been linked to very high morbidity and mortality rates. Until 2019, India remained free of LSD, resulting in a lack of locally developed diagnostic kits, biologicals, and other tools necessary for managing the disease in a country with such a large livestock population. Therefore, this study aimed to design and validate an indigenous and cost-effective in-house ELISA for large-scale screening of cattle samples for antibodies to LSDV. The viral major open reading frames ORF 095 and ORF 103 encoding virion core proteins were expressed in a prokaryotic system and the recombinant antigen cocktail was used for optimization and validation of an indirect ELISA (iELISA). The calculated relative diagnostic sensitivity and diagnostic specificity of the iELISA were 96.6 % and 95.1 %, respectively at the cut-off percent positivity (PP≥50 %). The in-house designed double-antigen iELISA was found effective to investigate the seroprevalence of LSDV in various geographical regions of India.

The first outbreak of Lumpy Skin Disease in Indonesia

This study describes the first outbreak of Lumpy Skin Disease (LSD) in cattle in the Bengkalis region, Indonesia, and vaccination to control the epidemic. Data on the outbreak and vaccination was obtained from the local veterinary authority of the Bengkalis region, Indonesia. Climatological data was provided by the Meteorological, Climatological, and Geophysical Agency of Riau Province. Over the 5.5 months, the outbreak caused 10.4% (94/906) morbidity and 0.6% (6/906) mortality of cattle on infected farms. Temporally, three epidemic waves occurred during the outbreak period. Villages with cattle populations of > 150 animals (n = 36) were 5.3 times more likely to be infected with LSD compared to villages with smaller cattle populations (n = 107) (CI: 2.56-10.90, P < 0.01). The vaccination campaign covered 43.8% of cattle in villages within a 10 km radius of the cases. However, vaccination in villages with larger cattle populations (n = 29) was 0.63 less likely to cover 50% of the cattle populations compared to villages with smaller cattle populations (n = 41) (CI: 0.39-1.02, P = 0.05). By the time the first two and the major waves ceased, vaccination had covered only 0.0% (n = 6036), 27.8% (n = 6,036) and 9.7% (n = 5,697) of the cattle in the 10 km radius of the respective spatial clusters. The outbreak was statistically associated with rainfall and its interaction with temperature (F(2, 13) = 5.822, R2 = 0.47, P = 0.016). This study indicates that the LSD outbreak had low morbidity and mortality. Despite the low vaccination rate, the outbreak ceased, possibly due to plummeting of the abundance of insect vectors.

Baculovirus expression and purification of virion core and envelope proteins of goatpox virus to evaluate their diagnostic potential

Goatpox and sheeppox are highly contagious and economically important viral diseases of small ruminants. Due to the risk they pose to animal health, livestock production, and international trade, capripoxviruses are a considerable threat to the livestock economy. In this study, we expressed two core proteins (A4L and A12L) and one extracellular enveloped virion protein (A33R) of goatpox virus in a baculovirus expression vector system and evaluated their use as diagnostic antigens in ELISA. Full-length A4L, A12L, and A33R genes of the GTPV Uttarkashi strain were amplified, cloned into the pFastBac HT A donor vector, and introduced into DH10Bac cells containing a baculovirus shuttle vector plasmid to generate recombinant bacmids. The recombinant baculoviruses were produced in Sf-21 cells by transfection, and proteins were expressed in TN5 insect cells. The recombinant proteins were analysed by SDS-PAGE and confirmed by western blot, with expected sizes of ~30 kDa, ~31 kDa, and ~32 kDa for A4L, A12L, and A33R, respectively. The recombinant proteins were purified, and the immunoreactivity of the purified proteins was confirmed by western blot using anti-GTPV serum. The antigenic specificity of the expressed proteins as diagnostic antigens was evaluated by testing their reactivity with infected, vaccinated, and negative GTPV/SPPV serum in indirect ELISA, and the A33R-based indirect ELISA was optimized. The diagnostic sensitivity and specificity of the A33R-based indirect ELISA were found to be of 89% and 94% for goats and 98% and 91%, for sheep, respectively. No cross-reactivity was observed with other related viruses. The recombinant-A33R-based indirect ELISA developed in the present study shows that it has potential for the detection of antibodies in GTPV and SPPV infected/vaccinated animals.

Deciphering the genetic landscape of lumpy skin disease: Unraveling variable virulence through comprehensive genome sequence analysis in India

Lumpy Skin Disease (LSD), a poxvirus disease affecting cattle, emerged in India in 2019 and intensified in 2022, resulting in significant economic losses for dairy farmers. There was unusual shift in mortality and morbidity patterns during the second wave. A comprehensive genetic study conducted, analyzing samples from 2019 to 2022 revealed circulation of two distinct subclades (subclade 1.2a and 1.2b) in India, with the latter showing a different pattern in morbidity and mortality. Notably, the Ankyrin repeats gene-based analysis could differentiate animals with varying clinical scores. Genetic variations were significant, with unique deletions identified, including a 12-nucleotide deletion in the GPCR gene in virus isolates collected during 2022 outbreaks, not reported earlier in Indian LSDV strains. A crucial finding was a significant 95-nucleotide deletion in the Functional Resolution Sequence (FRS) repeats of LSDV genomes from 2022 outbreaks, absent in 2019 samples. These deletions may have influenced the virus's virulence in India.

Epidemiological Characteristics of the Lumpy Skin Disease Outbreak in Nawalpur, Nepal, 2022

Lumpy skin disease (LSD) is an economically important and notifiable transboundary viral disease of cattle and water buffalo, predominantly transmitted by arthropod vectors. In recent times, LSD has emerged as a notable concern in Nepal, with the first outbreak reported in June 2020, in Morang district. In 2022, outbreaks of LSD were observed in several districts with Nawalpur district being the hard-hit district. The objective of this study is to provide insights into the epidemiological characteristics of LSD, to identify potential sources and associated risk factors for LSD outbreak in Nawalpur, and its financial impact. The overall morbidity rate was observed to be 28.02% (n = 431/1,538) and the mortality rate was 3.06% (n = 47/1,538), resulting in a case fatality rate of 10.90% (n = 47/431). The predominant clinical symptoms were skin nodules, lameness, and decreased milk production in milking animals. Dry cattle, including pregnant cows and cattle heifers were the most affected. Univariable logistic regression analysis identified factors linked to disease outbreaks, such as importing animals from disease prevalent regions, sharing feed and water, herd size, and the presence of clinical signs in neighboring farms. Multivariable analysis highlighted the significance of neighboring farms having sick animals in resulting disease outbreaks. Because of the substantial economic impact due to LSD, it is imperative to implement effective control and preventive measures. These include animal movement control and quarantine, following biosecurity protocols during nearby outbreaks, and targeted vaccination of susceptible populations to prevent further disease spread.

Persistence of passive immunity in calves receiving colostrum from cows vaccinated with a live attenuated lumpy skin disease vaccine and the performance of serological tests

This study aimed to determine the persistent duration of maternal immunity against lumpy skin disease virus (LSDV) in dairy calves born from vaccinated cows using a virus neutralization test (VNT). The performance of the VNT and an in-house-ELISA test was also determined. Thirty-seven pregnant cows from 12 LSD-free dairy farms in Lamphun province, Thailand were immunized with a homologous Neethling strain-based attenuated vaccine and calved from December 2021 to April 2022. Blood samples from dam-calve pairs were collected within the first week after calving. Subsequently, blood samples were taken from the calves at monthly intervals over a period of 4 months and tested for the humoral immune response using a VNT. The calf sera were also tested with an in-house ELISA test to estimate the accuracy of both tests using a Bayesian approach. For the results, antibodies against LSDV can persist in cows for 4-9 months post-vaccination. Moreover, neutralizing antibodies and LSDV-specific antibodies against LSDV were detected in the majority of calves (75.68%) during the first week after colostrum intake. However, the percentage of seropositive calves declined to zero by day 120, with seropositivity dropping below 50% after day 60. Only a small number of seropositive calves (approximately 13.51%) were observed on day 90. These findings indicated that passive immunity against LSDV can last up to 3 months. The median of posterior estimates for sensitivity (Se) and specificity (Sp) of the VNT were 87.3% [95% posterior probability interval (PPI) = 81.1-92.2%] and 94.5% (95% PPI = 87.7-98.3%), respectively. The estimated Se and Sp for the ELISA test were 83.1% (95% PPI = 73.6-92.6%) and 94.7% (95% PPI = 88.4-98.5%), respectively. In conclusion, this study illustrates the transfer and persistence of maternal passive immunity against LSDV to calves under field conditions. This highlights a potential three-month vaccination gap in calves born from vaccinated cows, while an in-house ELISA test can be used as an ancillary test for LSDV immune response detection. However, further research is required to assess the vaccination protocols for calves as young as 2 months old to precisely determine the duration of maternal immunity.

Epidemiological Risk Factors and Modelling Approaches for Risk Assessment of Lumpy Skin Disease Virus Introduction and Spread: Methodological Review and Implications for Risk-Based Surveillance in Australia

Lumpy skin disease (LSD) is a vector-borne infection caused by the poxvirus lumpy skin disease virus (LSDV) and is a serious disease of cattle, water buffalo, and banteng. While the disease has never occurred in Australia, it is regarded as a growing threat to the Australian cattle industry as there is on-going spread of the disease throughout Asia. The development of geospatial decision support tools, such as spatial epidemiological modelling, may assist in assessing areas at greater risk of this threat. To guide the design of disease modelling approaches to support future risk-based surveillance, existing LSDV epidemiological models need to be evaluated. In this study, we performed a literature review to evaluate existing LSDV epidemiological models, identify key risk factors for introduction and spread of LSDV, and consider previously adopted control strategies. The PRISMA guidelines were used to establish the processes for article selection and information extraction, and the PICO process was used to formulate search terms. From studies that met our inclusion criteria, we extracted information on LSDV epidemiological model structure and parameterisation, risk factors for LSDV transmission and spread, and biosecurity control strategies. The literature search retrieved a total of 402 articles from four databases, of which 68 were identified for inclusion in this review following screening. Of the 68 articles reviewed, 47 explored risk factors associated with LSDV transmission and spread, four explored risk factors of LSDV introduction, four explored existing surveillance strategies in LSD-free countries, and 14 presented epidemiological models. Our findings indicate that there are various risk factors for LSDV transmission in LSD endemic countries, including long-distance airborne movement of infected vectors such as stable flies and cattle movement between countries over land borders. Key risk factors for LSDV spread in LSD endemic countries include physical environmental characteristics, weather conditions, and population distributions of livestock and vectors. Our results indicate that while a variety of modelling studies have been conducted, the majority of studies experimentally explored LSD transmission mechanisms in vectors and cattle. Spatial and spatio-temporal models have primarily been developed for LSD endemic countries and focus on the spread of the disease in terms of environmental factors in relation to previous LSD events. There were very few studies on LSD-free countries, and these only focussed on risk of LSD introduction through specific entry pathways. This review did not identify any literature exploring the risk of spread of LSDV following introduction in LSD-free countries or geospatial modelling of the suitability of LSD-free countries for LSDV incursions. In conjunction with the risk parameters and models described in the identified literature, there is need to consider a wide range of risk factors specific to Australia to inform the design of risk-based surveillance for LSD in Australia.

Characterization, histopathology and immunogenicity of the lumpy skin disease virus isolated during 2019-20 in Bangladesh

Introduction

Lumpy skin disease (LSD) is a highly contagious vector-borne viral disease of cattle. LSD has emerged in Bangladesh in 2019, causing significant economic losses due to its high morbidity and mortality. This research was designed to isolate, identify, and assess the immunogenicity of LSD virus (LSDV) using nodular tissue samples obtained from affected cattle during the 2019-20 outbreak across nine districts of Bangladesh.

Methods

To determine the presence of LSDV in nodular tissues, we initially used iiPCR and PCR, followed by histopathological examination. 151 were positive via iiPCR and PCR among the 180 collected samples. The PCR positive 151 samples were then inoculated into 10-day-old embryonated chicken eggs via the CAM route to isolate LSDV, confirmed through PCR. Subsequently, partial sequencing and phylogenetic analysis of the P32 gene were performed to determine the origin of the circulating LSDV strain. The immunogenicity of selected LSDV strains was assessed through an ELISA test.

Results

The PCR results revealed a distinct positive band at 192 bp in both the nodular tissue samples and the LSDV isolated from chicken embryo inoculations. Microscopic analysis of the nodular lesions revealed thickening of the epidermis, ballooning degeneration of keratinocytes, and proliferation of follicular epithelia. Additionally, mononuclear infiltration was observed at the demarcation line between infected and healthy tissue, with necrosis of muscular tissues beneath the epidermis. The LSDV isolate from Bangladesh exhibited a close genetic relationship with LSDV strains isolated from neighboring and other regional countries including India, Myanmar, and Mongolia. This observation strongly suggests the possibility of a transboundary spread of the LSD outbreak in Bangladesh during 2019-2020. The results of the immunogenicity test showed that the serum antibody titer remained at a protective level for up to 18 months following secondary immunization with inactivated LSDV antigen. This finding suggests that the inactivated LSDV antigen could be a potential vaccine candidate to protect cattle in Bangladesh against LSDV.

Conclusion

In conclusion, our research successfully isolated, identified, and characterized LSDV in cattle nodular tissues from the 2019-20 outbreak in Bangladesh. Furthermore, it provided insights into the probable origin of the circulating strain and investigated a potential vaccine candidate to protect cattle in the region from LSDV.

An insight into emergence of lumpy skin disease virus: a threat to Indian cattle

Lumpy skin disease (LSD) is a highly infectious and economically devastating viral disease of cattle. It is caused by Lumpy Skin Disease Virus (LSDV) belonging to the genus Capripoxvirus and family Poxviridae. The origin of lumpy skin disease has been traced to Zambia, (an African nation) in Southern part during the year 1929. The first reported case of LSD besides Africa was from Israel, a Middle Eastern nation, thus proving inter-continental spread. Subsequently, the disease entered Middle East, Eastern Europe and Asia with numerous outbreaks in the recent years. LSD has emerged as a significant concern in the Indian sub-continent, due to outbreaks reported in countries such as Bangladesh, India, China in 2019. In the following years, other South and East Asian countries like Taipei, Nepal, Sri Lanka, Myanmar, Bhutan, Vietnam, Hong Kong, Thailand, Malaysia, Laos, Cambodia, Pakistan, Indonesia and Singapore also faced severe outbreaks. At present, LSD is considered to be an emerging disease in the Indian sub-continent due to the recent status of disease. Considering the global scenario, LSDV is changing its transmission dynamics as evidenced by a shift in its epidemiology. As a result of high morbidity and mortality rate among cattle, the current outbreaks have been a major cause of socio-economic catastrophe. This contagious viral disease has eminent repercussions as the estimated monetary damage incurred is quite high. Despite having networked surveillance and comprehensive databases, the recurring outbreaks have raised major concern among researchers. Therefore, this review offers brief insights into the emergence of LSDV by amalgamating the newest literature related to its biology, transmission, clinico-pathology, epidemiology, prevention strategies, and economic consequences. Additionally, we have also provided the epidemiological insights of the recent outbreaks with detailed state wise studies.

Construction of recombinant fluorescent LSDV for high-throughput screening of antiviral drugs

Lumpy skin disease virus (LSDV) infection is a major socio-economic issue that seriously threatens the global cattle-farming industry. Here, a recombinant virus LSDV-ΔTK/EGFP, expressing enhanced green fluorescent protein (EGFP), was constructed with a homologous recombination system and applied to the high-throughput screening of antiviral drugs. LSDV-ΔTK/EGFP replicates in various kidney cell lines, consistent with wild-type LSDV. The cytopathic effect, viral particle morphology, and growth performance of LSDV-ΔTK/EGFP are consistent with those of wild-type LSDV. High-throughput screening allowed to identify several molecules that inhibit LSDV-ΔTK/EGFP replication. The strong inhibitory effect of theaflavin on LSDV was identified when 100 antiviral drugs were screened in vitro. An infection time analysis showed that theaflavin plays a role in the entry of LSDV into cells and in subsequent viral replication stages. The development of this recombinant virus will contribute to the development of LSDV-directed antiviral drugs and the study of viral replication and mechanisms of action.

First evidence of lumpy skin disease in mithun (Bos frontalis) in India

Lumpy skin disease (LSD) is a disease of cattle that is also known to cause mild infection in buffaloes. To date, there have been no reports of LSD in mithun (Bos frontalis), a bovine species distributed in Northeast India, Bangladesh, Myanmar, and parts of China. In the present study, the presence of typical clinical signs, virus isolation, PCR amplification, sequence analysis, and the demonstration of antibodies in serum by indirect enzyme-linked immunosorbent assay and serum neutralization test, confirmed the occurrence of LSD in mithun for the first time in India. Phylogenetic analysis based on the full-length RPO30 and P32 genes of LSD virus from mithun and cattle revealed 100% sequence identity, indicating circulation of the same strain in both species in India and the possibility of spillover between species.

Emergence of lumpy skin disease virus (LSDV) infection in domestic Himalayan yaks (Bos grunniens) in Himachal Pradesh, India

In this study, we investigated and confirmed natural lumpy skin disease virus (LSDV) infection in Himalayan yaks (Bos grunniens) in Himachal Pradesh, India, based on clinical manifestations and results of genome detection, antibody detection, virus isolation, and nucleotide sequencing. Subsequent phylogenetic analysis based on complete GPCR, RPO30, and EEV gene sequences revealed that the LSDV isolates from these yaks and local cattle belonged to LSDV subcluster 1.2.1 rather than the dominant subcluster 1.2.2, which is currently circulating in India, suggesting a separate recent introduction. This is the first report of natural LSDV infection in yaks in India, expanding the known host range of LSDV. Further investigations are needed to assess the impact of LSDV infection in yaks.

Unravelling the genomic origins of lumpy skin disease virus in recent outbreaks

Lumpy skin disease virus (LSDV) belongs to the genus Capripoxvirus and family Poxviridae. LSDV was endemic in most of Africa, the Middle East and Turkey, but since 2015, several outbreaks have been reported in other countries. In this study, we used whole genome sequencing approach to investigate the origin of the outbreak and understand the genomic landscape of the virus. Our study showed that the LSDV strain of 2022 outbreak exhibited many genetic variations compared to the Reference Neethling strain sequence and the previous field strains. A total of 1819 variations were found in 22 genome sequences, which includes 399 extragenic mutations, 153 insertion frameshift mutations, 234 deletion frameshift mutations, 271 Single nucleotide polymorphisms (SNPs) and 762 silent SNPs. Thirty-eight genes have more than 2 variations per gene, and these genes belong to viral-core proteins, viral binding proteins, replication, and RNA polymerase proteins. We highlight the importance of several SNPs in various genes, which may play an essential role in the pathogenesis of LSDV. Phylogenetic analysis performed on all whole genome sequences of LSDV showed two types of variants in India. One group of the variant with fewer mutations was found to lie closer to the LSDV 2019 strain from Ranchi while the other group clustered with previous Russian outbreaks from 2015. Our study highlights the importance of genomic characterization of viral outbreaks to not only monitor the frequency of mutations but also address its role in pathogenesis of LSDV as the outbreak continues.

Lumpy skin disease: Insights into current status and geographical expansion of a transboundary viral disease

Lumpy skin disease (LSD) is an emerging transboundary viral disease of livestock animals which was first reported in 1929 in Zambia. Although LSD is a neglected disease of economic importance, it extends a direct impact on the international trade and economy in livestock-dependent countries. Lumpy skin disease virus (LSDV) has been endemic in African countries, where several outbreaks have been reported previously. However, the virus has spread rapidly across the Middle East in the past two decades, reaching Russia and, recently, the Asian subcontinent. With unprecedented cluster outbreaks being reported across Asian countries like India, China, Nepal, Bangladesh, and Pakistan, LSDV is certainly undergoing an epidemiological shift and expanding its geographical footprint worldwide. Due to high mortality among livestock animals, the recent LSD outbreaks have gained attention from global regulatory authorities and raised serious concerns among epidemiologists and veterinary researchers. Despite networked global surveillance of the disease, recurrent LSD cases pose a threat to the livestock industry. Hence, this review provides recent insights into the LSDV biology by augmenting the latest literature associated with its pathogenesis, transmission, current intervention strategies, and economic implications. The review critically examines the changing epidemiological footprint of LSDV globally, especially in relation to developing countries of the Asian subcontinent. We also speculate the possible reasons contributing to the ongoing LSD outbreaks, including illegal animal trade, climate change, genetic recombination events between wild-type and vaccine strains, reversion of vaccine strains to virulent phenotype, and deficiencies in active monitoring during the COVID-19 pandemic.

Cracking the Code of Lumpy Skin Disease: Identifying Causes, Symptoms and Treatment Options for Livestock Farmers

The novel bovine viral infection known as lumpy skin disease is common in most African and Middle Eastern countries, with a significant likelihood of disease transfer to Asia and Europe. Recent rapid disease spread in formerly disease-free zones highlights the need of understanding disease limits and distribution mechanisms. Capripox virus, the causal agent, may also cause sheeppox and Goatpox. Even though the virus is expelled through several bodily fluids and excretions, the most common causes of infection include sperm and skin sores. Thus, vulnerable hosts are mostly infected mechanically by hematophagous arthropods such as biting flies, mosquitoes, and ticks. As a result, milk production lowers, abortions, permanent or temporary sterility, hide damage, and mortality occur, contributing to a massive financial loss for countries that raise cattle. These illnesses are economically significant because they affect international trade. The spread of Capripox viruses appears to be spreading because to a lack of effectual vaccinations and poverty in rural areas. Lumpy skin disease has reached historic levels; as a consequence, vaccination remains the only viable option to keep the illness from spreading in endemic as well as newly impacted areas. This study is intended to offer a full update on existing knowledge of the disease's pathological characteristics, mechanisms of spread, transmission, control measures, and available vaccinations.

Biological properties and diverse cytokine profiles followed by in vitro and in vivo infections with LSDV strain isolated in first outbreaks in Vietnam

Preliminary information about LSD virus isolated from the first outbreaks in Vietnam has been reported by our laboratory. In the current study, LSDV strain, LSDV/Vietnam/Langson/HL01(HL01) was further analyzed to provide a better understanding of this viral pathogen. HL01 LSDV strain was propagated at MOI 0.01 in MDBK cells and then given to cattle at dose of 106.5 TCID50/ml (2ml/animal). The production of proinflammatory (IFN-γ, IL-1α, and TNF-α) and anti-inflammatory (IL-6, IL-10, and TGF-ß1) cytokines were measured by real-time PCR, both In vitro and In vivo. The results demonstrated that HL01 strain caused the typical signs of LSD and LSDV In vitro and In vivo, respectively suggesting a virulent field LSDV strain. Additionally, different cytokine profiles were observed in these In vitro and In vivo studies. In MDBK cells, different cytokines profiles were observed in two phases: in the early phase, the expression levels of all examined cytokines were significantly increased at 6 h (p < 0.05). In the later phase, the peak levels of the cytokine secretion were recognized from 72 to 96 h, with the exception of IL-1α when compared to controls. In cattle, the expression levels of all six cytokines were significantly higher at day 7 following LSDV challenge (p < 0.05) when compared to controls, especially expression levels of TGF-β1 and IL-10. These findings suggest the important roles of these cytokines in protection against LSDV infections. Additionally, the data from diverse cytokine profiles followed by this LSDV strain challenge provides key understanding of the underlying cellular immune mechanisms in the host against LSDV infection In vitro and In vivo.

Evaluation of the safety, immunogenicity and efficacy of a new live-attenuated lumpy skin disease vaccine in India

Lumpy skin disease (LSD) was reported for the first time in India in 2019 and since then, it has become endemic. Since a homologous (LSD-virus based) vaccine was not available in the country, goatpox virus (GPV)-based heterologous vaccine was authorized for mass immunization to induce protection against LSD in cattle. This study describes the evaluation of safety, immunogenicity and efficacy of a new live-attenuated LSD vaccine developed by using an Indian field strain, isolated in 2019 from cattle. The virus was attenuated by continuous passage (P = 50) in Vero cells. The vaccine (50^th LSDV passage in Vero cells, named as Lumpi-ProVac^Ind) did not induce any local or systemic reaction upon its experimental inoculation in calves (n = 10). At day 30 post-vaccination (pv), the vaccinated animals were shown to develop antibody- and cell-mediated immune responses and exhibited complete protection upon virulent LSDV challenge. A minimum Neethling response (0.018% animals; 5 out of 26,940 animals) of the vaccine was observed in the field trials conducted in 26,940 animals. There was no significant reduction in the milk yield in lactating animals (n = 10108), besides there was no abortion or any other reproductive disorder in the pregnant animals (n = 2889). Sero-conversion was observed in 85.18% animals in the field by day 30 pv.

Molecular characterization of lumpy skin disease virus from recent outbreaks in Pakistan

Lumpy skin disease (LSD) is a contagious viral transboundary disease listed as a notifiable disease by the World Organization of Animal Health (WOAH). The first case of this disease was reported in Pakistan in late 2021. Since then, numerous outbreaks have been documented in various regions and provinces across the country. The current study primarily aimed to analyze samples collected during LSD outbreaks in cattle populations in the Sindh and Punjab provinces of Pakistan. Phylogenetic analysis was conducted using partial sequences of the GPCR, p32, and RP030 genes. Collectively, the LSDV strains originating from outbreaks in Pakistan exhibited a noticeable clustering pattern with LSDV strains reported in African, Middle Eastern, and Asian countries, including Egypt, the Kingdom of Saudi Arabia, India, China, and Thailand. The precise reasons behind the origin of the virus strain and its subsequent spread to Pakistan remain unknown. This underscores the need for further investigations into outbreaks across the country. The findings of the current study can contribute to the establishment of effective disease control strategies, including the implementation of a mass vaccination campaign in disease-endemic countries such as Pakistan.

Lumpy Skin Disease (LSD) in Yak (Bos grunniens): An Evidence of Species Spillover from Cattle in India

Lumpy skin disease (LSD), caused by the lumpy skin disease virus (LSDV), is a global concern that affects cattle and buffalo. Recently, the disease has been reported in new species such as the Indian Gazelle, Camel, Banteng, Gaur, and Giraffe from various parts of the world. This report provides an insight into the occurrence of LSD in Yak from Sikkim, a North-Eastern state of India. During the investigation, both cattle and yak exhibited typical clinical signs of LSD, including skin nodular lesions. The morbidity, mortality, and case fatality rates for cattle were 9.08%, 1.84%, and 20.24%, respectively. Similarly, the morbidity, mortality, and case fatality rates in yak were 7.57%, 1.24%, and 16.33%, respectively. The virus isolation and amplification of LSDV-specific genes confirmed the presence of LSDV in cattle, yak, and vectors. Further, demonstrated antibodies in randomly collected sera from naïve and unvaccinated cattle and yak using indirect Enzyme Linked Immuno-sorbent Assay (iELISA) and Serum Neutralisation test (SNT) from this region. Sequencing and phylogenetic analysis of P32, GPCR, and RPO30 genes revealed that the virus isolated from both species was 100% identical to each other and also closely related to the field LSDV isolates circulating in the Indian subcontinent. The study highlighted the emergence of LSDV in unconventional hosts and underscored the need to include other bovine species in national disease control programs, encompassing disease surveillance initiatives.

Complete genome sequence of the lumpy skin disease virus reported from Jammu and Kashmir, India, during 2022 outbreak

Lumpy skin disease virus (LSDV) is the causative agent of an economically important disease of cattle and water buffaloes. Here, we announce the complete genome sequence of the LSDV from Jammu and Kashmir, India. LSDV/02/KASH/IND/2022 was detected in skin biopsy sample of an LSD-infected dairy cow on 24 October 2022.

Lumpy skin disease: history, current understanding and research gaps in the context of recent geographic expansion

Lumpy skin disease is recognized as a transboundary and emerging disease of cattle, buffaloes and other wild ruminants. Being initially restricted to Africa, and since 1989 the Middle East, the unprecedented recent spread across Eurasia demonstrates how underestimated and neglected this disease is. The initial identification of the causative agent of LSD as a poxvirus called LSD virus, was well as findings on LSDV transmission and epidemiology were pioneered at Onderstepoort, South Africa, from as early as the 1940s by researchers such as Weiss, Haig and Alexander. As more data emerges from an ever-increasing number of epidemiological studies, previously emphasized research gaps are being revisited and discussed. The currently available knowledge is in agreement with the previously described South African research experience that LSDV transmission can occur by multiple routes, including indirect contact, shared water sources and arthropods. The virus population is prone to molecular evolution, generating novel phylogenetically distinct variants resulting from a diverse range of selective pressures, including recombination between field and homologous vaccine strains in cell culture that produce virulent recombinants which pose diagnostic challenges. Host restriction is not limited to livestock, with certain wild ruminants being susceptible, with unknown consequences for the epidemiology of the disease.

Field-friendly and ultra-fast detection platform without nucleic acid extraction for virus detection

The polymeric chain reaction (PCR) has come under fire for being time-consuming, requiring expensive equipments, and requiring the extraction and purification of nucleic acids. Here, an ultra-fast and sensitive detection platform without nucleic acid extraction solved the above problems. Firstly, the RoomTemp Sample Lysis Kit released the nucleic acid in 3 min and removed the inhibition to facilitate the amplification reaction. What's more, ultra-fast PCR (UF-PCR) can complete 40 cycles in just 15 min and 50 s. To improve the sensitivity and provide more convenient reading modes, CRISPR/Cas12a was mediated to detect Lumpy skin disease virus (LSDV). The platform output fluorescence and Lateral flow dipstick (LFD) signals. The actual detection limit was 2 × 101 copies·μL-1. The portable platform realized visualization, excellent sensitivity and quick speed. In summary, the field-friendly testing platform had great potential in practical testing.

Global Burden of Lumpy Skin Disease, Outbreaks, and Future Challenges

Lumpy skin disease (LSD), a current global concern, causes economic devastation in livestock industries, with cattle and water buffalo reported to have higher morbidity and lower mortality rates. LSD is caused by lumpy skin disease virus (LSDV), a member of the Poxviridae family. It is an enzootic, rapidly explorative and sometimes fatal infection, characterized by multiple raised nodules on the skin of infected animals. It was first reported in Zambia in 1929 and is considered endemic in Africa south of the Sahara desert. It has gradually spread beyond Africa into the Middle East, with periodic occurrences in Asian and East European countries. Recently, it has been spreading in most Asian countries including far East Asia and threatens incursion to LSD-free countries. Rapid and accurate diagnostic capabilities, virus identification, vaccine development, vector control, regional and international collaborations and effective biosecurity policies are important for the control, prevention, and eradication of LSD infections. This review critically evaluates the global burden of LSD, the chronological historical outbreaks of LSD, and future directions for collaborative global actions.

Multiple accurate and sensitive arrays for Capripoxvirus (CaPV) differentiation

Capripoxvirus (CaPV) contains three viruses that have caused massive losses in the livestock and dairy industries. Accurate CaPV differentiation has far-reaching implications for effectively controlling outbreaks. However, it has a great challenge to distinguishing three viruses due to high homology of 97%. Here, we established a sensitive CRISPR/Cas12a array based on Multiple-recombinase polymerase amplification (M-RPA) for CaPV differentiation, which provided a more comprehensive and accurate differentiation mode targeting VARV B22R and RPO30 genes. By sensitive CRISPR/Cas12a and M-RPA, the actual detection limits of three viruses were as low as 50, 40 and 60 copies, respectively. Moreover, Lateral flow dipstick (LFD) array based on CRISPR/Cas12a achieved portable and intuitive detection, making it suitable for point-of-care testing. Therefore, CRISPR/Cas12a array and LFD array paved the way for CaPV differentiation in practice. Additionally, we constructed a real-time quantitative PCR (qPCR) array to fill the qPCR technical gap in differentiation and to facilitate the quarantine departments.

Lumpy Skin Disease: A Systematic Review of Mode of Transmission, Risk of Emergence and Risk Entry Pathway

The spread of lumpy skin disease (LSD) to free countries over the last 10 years, particularly countries in Europe, Central and South East Asia, has highlighted the threat of emergence in new areas or re-emergence in countries that achieved eradication. This review aimed to identify studies on LSD epidemiology. A focus was made on hosts, modes of transmission and spread, risks of outbreaks and emergence in new areas. In order to summarize the research progress regarding the epidemiological characteristics of LSD virus over the last 40 years, the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement guidelines were followed, via two databases, i.e., PubMed (biomedical literature) and Scopus (peer-reviewed literature including scientific journals, books, and conference proceedings). A total of 86 scientific articles were considered and classified according to the type of epidemiological study, i.e., experimental versus observational. The main findings and limitations of the retrieved articles were summarized: buffaloes are the main non-cattle hosts, the main transmission mode is mechanical, i.e., via blood-sucking vectors, and stable flies are the most competent vectors. Vectors are mainly responsible for a short-distance spread, while cattle trade spread the virus over long distances. Furthermore, vaccine-recombinant strains have emerged. In conclusion, controlling animal trade and insects in animal transport trucks are the most appropriate measures to limit or prevent LSD (re)emergence.

Lumpy Skin Disease Virus Infection in Free-Ranging Indian Gazelles (Gazella bennettii), Rajasthan, India

Near a zoo in Bikaner, India, 2 free-ranging Indian gazelles (Gazella bennettii) displayed nodular skin lesions. Molecular testing revealed lumpy skin disease virus (LSDV) infection. Subsequent genome analyses revealed LSDV wild-type strain of Middle Eastern lineage. Evidence of natural LSDV infection in wild gazelles in this area indicates a broadening host range.

The End of the Gray Zone: One-Tube Nested Recombinase Polymerase Amplification with Ultrahigh Signal-to-Noise Ratio for Precisely Detecting and Surveilling Viruses

The samples were difficult to accurately determine positive or negative between 35 and 40 cycles by real-time quantitative PCR (qPCR) as the standard method. Here, we developed one-tube nested recombinase polymerase amplification (ONRPA) technology with CRISPR/Cas12a to overcome this difficulty. ONRPA broke the amplification plateau to substantially enhance the signals, which considerably improved the sensitivity and eliminated the problem of gray area. Using two pairs of primers one after another, it improved precision by lowering the probability of magnifying several target zones, which was completely free of contamination by nonspecific amplification. This was important in nucleic acid testing. Finally, by the CRISPR/Cas12a system as a terminal output, the approach achieved a high signal output as few as 2.169 copies·μL^-1 in 32 min. ONRPA was 100-fold more sensitive than conventional RPA and 1000-fold compared to qPCR. ONRPA coupled with CRISPR/Cas12a will be an important and new promoter of RPA in clinical applications.

The Spread of Lumpy Skin Disease Virus across Southeast Asia: Insights from Surveillance

Lumpy skin disease (LSD) is a notifiable, transboundary disease, causing substantial economic and welfare impacts in cattle. Prior to October 2020, LSD had not been reported in Southeast Asia; however, on 5 October 2020, Vietnam reported the first case in the region. This study aimed to investigate the initial spread of LSD virus (LSDV) in cattle across Southeast Asia between October 2020 and October 2021. LSD outbreak data were accessed from the World Organisation for Animal Health (WOAH) World Animal Health Information System (WAHIS) database and analysed to investigate this spread via epidemic curves, disease maps, clustering, and descriptive statistics. During the epidemic period, 866 LSD outbreaks were reported from six Southeast Asian countries, consisting of 1,758,923 susceptible cattle, 93,465 cases, 5,936 deaths, and 1,117 cattle culled. Analysis revealed a propagated epidemic throughout Southeast Asia, with four major peaks in case numbers across Thailand and Vietnam. Three clusters of reported outbreaks were identified, and Thailand was found to be the epicentre of the outbreak in the region, which could reflect reporting bias and underreporting from other countries in Southeast Asia. High morbidity and mortality rates were reported, particularly in Thailand, Vietnam, and Cambodia, likely reflective of infection in a naïve population and lack of an effective vaccination program. These findings are in contrast to what has generally been described in other parts of the world. Furthermore, studies should examine the risk factors associated with high morbidity and mortality rates in this region. A greater understanding of LSD epidemiology in Southeast Asia will assist farmers and governments to implement effective control and prevention strategies that reduce the spread of disease to other regions and the potentially devastating impacts of LSD.

Evidence of lumpy skin disease virus infection in camels

Countries in the Indian subcontinent are currently facing a deadly epidemic of lumpy skin disease (LSD).  LSD is primarily a disease of cattle. Buffaloes may sometimes develop mild illness, however, other domestic animals are considered resistant to LSD. We confirmed the LSDV infection in camels as evidenced by skin nodules on the body surface of the affected camels, isolation of LSD virus (LSDV) and amplification of LSDV-specific gene segments from the skin nodules (PCR), nucleotide sequencing of the viral genome and, demonstration of anti-LSDV antibodies in serum. Phylogenetic analysis based on nucleotide sequencing of ORF011, ORF012 and ORF036 revealed that the virus (LSDV/Camel/India/2022/Bikaner) is related to the historical NI-2490/Kenya/KSGP-like field strains which are predominantly circulating in the Indian subcontinent. This is the first report wherein LSDV has been to infect camels.

First complete genome sequence of lumpy skin disease virus directly from a clinical sample in South India

Lumpy skin disease (LSD), a notifiable disease listed by the World Organization for Animal Health and a fast fast-moving transboundary viral disease infecting cattle and buffaloes, was reported in India in 2019 and has since rapidly spread across the country. This study reports the first complete genome sequence and analysis of a pathogenic LSD virus (LSDV) from India (LSDV/208/PVNRTVU/2020) obtained by direct sequencing of a suspected clinical sample using Illumina and Nanopore sequencing technologies. The complete genome sequence of LSDV/208/PVNRTVU/2020 is 150445 bp long, codes for 156 putative genes and carries identical 2254 bp inverted terminal repeats at either ends. The unique features reported in the LSDV isolates from the recent outbreaks in Asia, namely, the insertions of 12 nucleotides in the viral G-protein coupled receptor (GPCR) and 27 nucleotides leading to duplication of 9 aminoacids in the extracellular enveloped virus-specific (EEV) genes were also conserved in LSDV/208/PVNRTVU/2020. Phylogenetic analysis of the complete genome sequence of LSDV/208/PVNRTVU/2020 revealed its close relation with Kenyan strains and clustered away from vaccine strains. Further analysis showed evidence of strong purifying selection without any recombination events. The data presented in this study could be useful for designing effective strategies such as developing rapid diagnostics and vaccines to control LSD.

Development and Validation of a New DIVA Real-Time PCR Allowing to Differentiate Wild-Type Lumpy Skin Disease Virus Strains, Including the Asian Recombinant Strains, from Neethling-Based Vaccine Strains

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.

An Extensive Examination of the Warning Signs, Symptoms, Diagnosis, Available Therapies, and Prognosis for Lumpy Skin Disease

The lumpy skin disease virus (LSDV) infects cattle and buffalo and causes lumpy skin disease (LSD). It affects the lymph nodes of the sick animals, causing them to enlarge and appear as lumps (cutaneous nodules) that are 2–5 cm in diameter on their heads, necks, limbs, udders, genitalia, and perinea. A high temperature, a sharp drop in milk supply, discharge from the eyes and nose, salivation, a loss of appetite, depression, damaged hides, and emaciation are further warning signs and symptoms. As per the Food and Agriculture Organization (FAO), the incubation period, or the time between an infection and symptoms, is approximately 28 days. Infected animals can transfer the virus by direct contact with the vectors, direct virus secretion from mouth or nose, shared feeding and watering troughs, and even artificial insemination. The World Organization for Animal Health (WOAH) and the FAO both warn that the spread of illnesses could lead to serious economic losses. This illness reduces cow’s milk production because oral ulcers make the animal weak and lead them to lose their appetite. There are many diagnostics available for LSDV. However, very few tests yield accurate findings. The best methods for preventing and controlling the lumpy skin condition include vaccination and movement restrictions. As a specific cure is not available, the only available treatment for this illness is supportive care for cattle. Recently, India has developed a homologous, live-attenuated vaccine, Lumpi-ProVacInd, which is specifically intended to protect animals against the LSD virus. This study’s primary goal is to accumulate data on symptoms, the most accurate method of diagnosis, treatments, and controls to stop infections from spreading as well as to explore future possibilities for the management of LSDV.