Seminal Transmission of Lumpy Skin Disease Virus in Heifers

Lumpy Skin Disease: Insights into Molecular Pathogenesis and Control Strategies

Lumpy skin disease (LSD) is a viral infection that affects buffaloes and cattle across various regions, including both tropical and temperate climates. Intriguingly, the virus-carrying skin sores remain the primary source of infection for extended periods, exacerbated by the abundance of vectors in disease-endemic countries. Recent scientific advances have revealed the molecular aspects of LSD and offered improved vaccines and valuable antiviral targets. This review summarizes the molecular features of LSD and its effect on various livestock species. We then provide an extensive discussion on the transmission dynamics of LSD and the roles of vectors in its continued spread among livestock populations. Additionally, this review critically analyses the rationales behind, as well as the affordability and effectiveness, of current control strategies worldwide.

An extensive investigation of convolutional neural network designs for the diagnosis of lumpy skin disease in dairy cows

Cow diseases are a major source of concern for people. Some diseases in animals that are discovered in their early stages can be treated while they are still treatable. If lumpy skin disease (LSD) is not properly treated, it can result in significant financial losses for the farm animal industry. Animals like cows that sign this disease have their skin seriously affected. A reduction in milk production, reduced fertility, growth retardation, miscarriage, and occasionally death are all detrimental effects of this disease in cows. Over the past three months, LSD has affected thousands of cattle in nearly fifty districts across Bangladesh, causing cattle farmers to worry about their livelihood. Although the virus is very contagious, after receiving the right care for a few months, the affected cattle can be cured. The goal of this study was to use various deep learning and machine learning models to determine whether or not cows had lumpy disease. To accomplish this work, a Convolution neural network (CNN) based novel architecture is proposed for detecting the illness. The lumpy disease-affected area has been identified using image preprocessing and segmentation techniques. After the extraction of numerous features, our proposed model has been evaluated to classify LSD. Four CNN models, DenseNet, MobileNetV2, Xception, and InceptionResNetV2 were used to classify the framework, and evaluation metrics were computed to determine how well the classifiers worked. MobileNetV2 has been able to achieve 96% classification accuracy and an AUC score of 98% by comparing results with recently published relevant works, which seems both good and promising.

Molecular characterization of recombinant LSDV isolates from 2022 outbreak in Indonesia through phylogenetic networks and whole-genome SNP-based analysis

Lumpy skin disease (LSD) is a transboundary viral disease of cattle and water buffaloes caused by the LSD virus, leading to high morbidity, low mortality, and a significant economic impact. Initially endemic to Africa only, LSD has spread to the Middle East, Europe, and Asia in the past decade. The most effective control strategy for LSD is the vaccination of cattle with live-attenuated LSDV vaccines. Consequently, the emergence of two groups of LSDV strains in Asian countries, one closely related to the ancient Kenyan LSDV isolates and the second made of recombinant viruses with a backbone of Neethling-vaccine and field isolates, emphasized the need for constant molecular surveillance. This current study investigated the first outbreak of LSD in Indonesia in 2022. Molecular characterization of the isolate circulating in the country based on selected LSDV-marker genes: RPO30, GPCR, EEV glycoprotein gene, and B22R, as well as whole genome analysis using several analytical tools, indicated the Indonesia LSDV isolate as a recombinant of LSDV_Neethling_vaccine_LW_1959 and LSDV_NI-2490. The analysis clustered the Indonesia_LSDV with the previously reported LSDV recombinants circulating in East and Southeast Asia, but different from the recombinant viruses in Russia and the field isolates in South-Asian countries. Additionally, this study has demonstrated alternative accurate ways of LSDV whole genome analysis and clustering of isolates, including the recombinants, instead of whole-genome phylogenetic tree analysis. These data will strengthen our understanding of the pathogens' origin, the extent of their spread, and determination of suitable control measures required.

Analysis of factors associated with the first lumpy skin disease outbreaks in naïve cattle herds in different regions of Thailand

Introduction

Thailand experienced a nationwide outbreak of lumpy skin disease (LSD) in 2021, highlighting the need for effective prevention and control strategies. This study aimed to identify herd-level risk factors associated with LSD outbreaks in beef cattle herds across different regions of Thailand.

Methods

A case-control study was conducted in upper northeastern, northeastern, and central regions, where face-to-face interviews were conducted with farmers using a semi-structured questionnaire. Univariable and multivariable mixed effect logistic regression analyses were employed to determine the factors associated with LSD outbreaks. A total of 489 beef herds, including 161 LSD outbreak herds and 328 non-LSD herds, were investigated.

Results and discussion

Results showed that 66% of farmers have operated beef herds for more than five years. There were very few animal movements during the outbreak period. None of the cattle had been vaccinated with LSD vaccines. Insects that have the potential to act as vectors for LSD were observed in all herds. Thirty-four percent of farmers have implemented insect control measures. The final mixed effect logistic regression model identified herds operating for more than five years (odds ratio [OR]: 1.62, 95% confidence interval [CI]: 1.04-2.53) and the absence of insect control management on the herd (OR: 2.05, 95% CI: 1.29-3.25) to be associated with LSD outbreaks. The implementation of insect-vector control measures in areas at risk of LSD, especially for herds without vaccination against the disease, should be emphasized. This study provides the first report on risk factors for LSD outbreaks in naïve cattle herds in Thailand and offers useful information for the development of LSD prevention and control programs within the country's context.

Metagenomic profiling of viral and microbial communities from the pox lesions of lumpy skin disease virus and sheeppox virus-infected hosts

Introduction

It has been recognized that capripoxvirus infections have a strong cutaneous tropism with the manifestation of skin lesions in the form of nodules and scabs in the respective hosts, followed by necrosis and sloughing off. Considering that the skin microbiota is a complex community of commensal bacteria, fungi and viruses that are influenced by infections leading to pathological states, there is no evidence on how the skin microbiome is affected during capripoxvirus pathogenesis.

Methods

In this study, shotgun metagenomic sequencing was used to investigate the microbiome in pox lesions from hosts infected with lumpy skin disease virus and sheep pox virus.

Results

The analysis revealed a high degree of variability in bacterial community structures across affected skin samples, indicating the importance of specific commensal microorganisms colonizing individual hosts. The most common and abundant bacteria found in scab samples were Fusobacterium necrophorum, Streptococcus dysgalactiae, Helcococcus ovis and Trueperella pyogenes, irrespective of host. Bacterial reads belonging to the genera Moraxella, Mannheimia, Corynebacterium, Staphylococcus and Micrococcus were identified.

Discussion

This study is the first to investigate capripox virus-associated changes in the skin microbiome using whole-genome metagenomic profiling. The findings will provide a basis for further investigation into capripoxvirus pathogenesis. In addition, this study highlights the challenge of selecting an optimal bioinformatics approach for the analysis of metagenomic data in clinical and veterinary practice. For example, direct classification of reads using a kmer-based algorithm resulted in a significant number of systematic false positives, which may be attributed to the peculiarities of the algorithm and database selection. On the contrary, the process of de novo assembly requires a large number of target reads from the symbiotic microbial community. In this work, the obtained sequencing data were processed by three different approaches, including direct classification of reads based on k-mers, mapping of reads to a marker gene database, and de novo assembly and binning of metagenomic contigs. The advantages and disadvantages of these techniques and their practicality in veterinary settings are discussed in relation to the results obtained.

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.

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.

Comparison of Gross Pathology between Classical and Recombinant Lumpy Skin Disease Viruses

The pathology caused by three different isolates of lumpy skin disease virus, classical field cluster 1.2 strain Dagestan/2015, recombinant vaccine-like cluster 2.1 strain Saratov/2017, and cluster 2.2 strain Udmurtiya/2019, in cattle was compared from experimental infections. The infection of cattle was performed using intravenous administration of 2 mL of 105 TCID50/mL of each specific LSDV. Both classical and recombinant forms of LSDV cause pathological changes in the skin and lymph nodes, as well as the trachea and lungs. Due to circulatory disorders in the affected organs, multiple areas of tissue necrosis were observed, which, with the resurgence of secondary microflora, led to the development of purulent inflammation. Observed pathological changes caused by the recombinant vaccine-like strain Udmurtiya/2019 were characterized by a more pronounced manifestation of the pathoanatomical picture compared to the classical field strains Dagestan/2015 and Saratov/2017. Interestingly, Dagestan/2015 and Udmurtiya/2019 caused damage to the lymph nodes, characterized by serous inflammation and focal purulent lymphadenitis caused by purulent microflora. "Saratov/2017" did not cause pathology in the lymph nodes. All LSDVs were virulent and caused pathology, which was not distinguishable between viruses. This data set will serve as the experimentally validated basis for the comparative examination of novel LSDV strains in gross pathology.

A quantitative risk assessment for the incursion of lumpy skin disease virus into Australia via long-distance windborne dispersal of arthropod vectors

Lumpy skin disease (LSD) is an infectious disease of cattle and water buffalo caused by lumpy skin disease virus (LSDV). It is primarily transmitted mechanically by biting insects. LSDV has spread from Africa to the Middle-East, the Balkans, Caucasus, Russia, Kazakhstan, China, Asia and India, suggesting that a wide variety of arthropod vectors are capable of mechanical transmission. In 2022, LSD was detected in Indonesia, heightening awareness for Australia's livestock industries. To better understand the risk of LSDV incursion to Australia we undertook a quantitative risk assessment (QRA) looking at windborne dispersal of arthropod vectors, assuming a hypothetical situation where LSD is endemic in south-east Asia and Papua New Guinea. We estimated the risk of LSDV incursion to be low, with a median incursion rate of one incursion every 403 years, based on a model where several infectious insects (i.e. a 'small batch' of 3-5) must bite a single bovine to transmit infection. The incursion risk increases substantially to one incursion every 7-8 years if a bite from a single insect is sufficient for transmission. The risk becomes negligible (one incursion every 20,706 years) if bites from many insects (i.e. a 'large batch' of 30-50 insects) are necessary. Critically, several of our parameter estimates were highly uncertain during sensitivity analyses. Thus, a key outcome of this QRA was to better prioritise surveillance activities and to understand the key research gaps associated with LSDV in the Australasian context. The current literature shows that multiple vectors are required for successful bovine-to-vector transmission of LSDV, suggesting that our estimate of one outbreak every 403 years more accurately represents the risk to Australia; however, the role of single insects in transmission has not yet been evaluated. Similarly, attempts to transmit LSDV between bovines by Culicoides have not been successful, although midges were the highest risk vector category in our model due to the high vector-to-host ratio for midges compared to other vector categories. Our findings provide further insight into the risk of LSD to Australian cattle industries and identify the Tiwi Islands and areas east of Darwin as priority regions for LSDV surveillance, especially between December and March.

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.

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.

Poxvirus Infections in Dairy Farms and Transhumance Cattle Herds in Nigeria

Lumpy Skin disease (LSD) is an economically important disease in cattle caused by the LSD virus (LSDV) of the genus Capripoxvirus, while pseudocowpox (PCP) is a widely distributed zoonotic cattle disease caused by the PCP virus (PCPV) of the genus Parapoxvirus. Though both viral pox infections are reportedly present in Nigeria, similarities in their clinical presentation and limited access to laboratories often lead to misdiagnosis in the field. This study investigated suspected LSD outbreaks in organized and transhumance cattle herds in Nigeria in 2020. A total of 42 scab/skin biopsy samples were collected from 16 outbreaks of suspected LSD in five northern States of Nigeria. The samples were analyzed using a high-resolution multiplex melting (HRM) assay to differentiate poxviruses belonging to Orthopoxvirus, Capripoxvirus, and Parapoxvirus genera. LSDV was characterized using four gene segments, namely the RNA polymerase 30 kDa subunit (RPO30), G-protein-coupled receptor (GPCR), the extracellular enveloped virus (EEV) glycoprotein and CaPV homolog of the variola virus B22R. Likewise, the partial B2L gene of PCPV was also analyzed. Nineteen samples (45.2%) were positive according to the HRM assay for LSDV, and five (11.9%) were co-infected with LSDV and PCPV. The multiple sequence alignments of the GPCR, EEV, and B22R showed 100% similarity among the Nigerian LSDV samples, unlike the RPO30 phylogeny, which showed two clusters. Some of the Nigerian LSDVs clustered within LSDV SG II were with commonly circulating LSDV field isolates in Africa, the Middle East, and Europe, while the remaining Nigerian LSDVs produced a unique sub-group. The B2L sequences of Nigerian PCPVs were 100% identical and clustered within the PCPV group containing cattle/Reindeer isolates, close to PCPVs from Zambia and Botswana. The results show the diversity of Nigerian LSDV strains. This paper also reports the first documented co-infection of LSDV and PCPV in Nigeria.

Lumpy Skin Disease—An Emerging Cattle Disease in Europe and Asia

Lumpy skin disease virus (LSDV) is a member of the Capripoxvirus genus, mainly infecting cattle and buffalo, which until relatively recently was only endemic in parts of Africa and then spread to the Middle East and lately Europe and Asia. Lumpy skin disease (LSD) is a notifiable disease with a serious impact on the beef industry as it causes mortality of up to 10% and has impacts on milk and meat production, as well as fertility. The close serological relationship between LSDV, goat poxvirus (GTPV) and sheep poxvirus (SPPV) has led to live attenuated GTPV and SPPV vaccines being used to protect against LSD in some countries. There is evidence that the SPPV vaccine does not protect from LSD as well as the GTPV and LSDV vaccines. One of the LSD vaccines used in Eastern Europe was found to be a combination of different Capripoxviruses, and a series of recombination events in the manufacturing process resulted in cattle being vaccinated with a range of recombinant LSDVs resulting in virulent LSDV which spread throughout Asia. It is likely that LSD will become endemic throughout Asia as it will be very challenging to control the spread of the virus without widespread vaccination.

Understanding the research advances on lumpy skin disease: A comprehensive literature review of experimental evidence

Lumpy skin disease is caused by lumpy skin disease virus (LSDV), which can induce cattle with high fever and extensive nodules on the mucosa or the scarfskin, seriously influencing the cattle industry development and international import and export trade. Since 2013, the disease has spread rapidly and widely throughout the Russia and Asia. In the past few decades, progress has been made in the study of LSDV. It is mainly transmitted by blood-sucking insects, and various modes of transmission with distinct seasonality. Figuring out how the virus spreads will help eradicate LSDV at its source. In the event of an outbreak, selecting the most effective vaccine to block and eliminate the threat posed by LSDV in a timely manner is the main choice for farmers and authorities. At present, a variety of vaccines for LSDV have been developed. The available vaccine products vary in quality, protection rate, safety and side effects. Early detection of LSDV can help reduce the cost of disease. In addition, because LSDV has a huge genome, it is currently also used as a vaccine carrier, forming a new complex with other viral genes through homologous recombination. The vaccine prepared based on this can have a certain preventive effect on many kinds of diseases. Clinical detection of disease including nucleic acid and antigen level. Each method varies in convenience, accuracy, cost, time and complexity of equipment. This article reviews our current understanding of the mode of transmission of LSDV and advances in vaccine types and detection methods, providing a background for further research into various aspects of LSDV in the future.

Lumpy Skin Disease: An Economically Significant Emerging Disease

Lumpy skin disease (LSD) is a severe viral disease of cattle caused by the lumpy skin disease virus (LSDV), a member of the Capripoxvirus genus of the poxviridae family. Fever and flat disk-like skin nodules on the skin characterize the disease. It can also lead to death and significant economic losses, especially in herds, that have never been exposed to the virus. Blood-feeding insects, such as specific types of flies, mosquitoes, and ticks, are thought to be the primary vectors of LSDV transmission. Most African and middle eastern countries have a high prevalence of lumpy skin disease. The disease extended to southeast Europe, the Balkans, and the Caucasus in 2015 and 2016 and is still spreading throughout Asia. The World Organization for Animal Health [WOAH] has designated LSD as a notifiable illness due to the likelihood of fast transmission. The rapid spread of disease in formerly disease-free areas emphasizes the need to know the disease epidemiology and the virus’s interaction with its host. This chapter aims to provide the latest developments in the etiology, epidemiology, diagnosis, and control of LSD.

The changing epidemiology of lumpy skin disease in Russia since the first introduction from 2015 to 2020

Lumpy skin disease (LSD) is an economically important transboundary disease affecting cattle, causing large economic losses such as decreased production and trade restrictions. LSD has been a historically neglected disease since it previously caused disease limited to the African continent. Currently, the epidemiology of LSD virus is based on how the disease is transmitted in tropical and sub-tropical climates. The understanding of its epidemiology in hemiboreal climates is not well understood and needs urgent attention to expand the current knowledge. In this study, the epidemiological findings on LSD in Russia over a 6-year period are summarized and discussed. A total of 471 outbreaks were identified spanning over a 9000 km range. The outbreaks of LSD occur primarily in small holder farms (backyard) compared to commercial farms between mid-May through mid-November including weather conditions with snow and freezing temperatures that preclude vector activity. Mortality and morbidity varied across the 6 years ranging from 1.19% to 61.8% and 0% to 50%, respectively, with a tendency to decline from 2015 to 2020. The geographic pattern of spread was assessed by means of directionality, indicating a northward movement from 2015 to 2016, with a consequent East turn in 2017 through Siberia to the Far East by 2020. All cases occurred along the border with Kazakhstan. Mathematical modelling showed that the disease tended to form statistically verified annual spatiotemporal clusters in 2016-2018, whereas in 2019 and 2020 such segregation was not evident. The trend of spread was mainly either from south to north or from south to a north-east direction.

Update of Lumpy Skin Disease: Emergence in Asian Part of Eurasia

Lumpy skin disease (LSD) is an infectious disease mostly of cattle. The typical clinical picture is usually characterized by the appearance of multiple nodules on the skin and internal organs. They can cover the entire body of the animal in the course of severe illness. This disease causes serious economic damage despite the fact that mortality of cattle with LSD is often low. Now LSD is a serious danger for cattle in the Asian part of Russia (part of the territory of the Russian Federation geographically belonging to Asia) and the Southeast Asia. Initially LSD was an endemic disease in many Sub-Saharan African countries, then it spread to Asia and Europe. In order to prevent the spread of the lumpy skin disease virus (LSDV), strict quarantine is introduced, vector control is carried out and various other LSD control measures are implemented. An effective vaccination campaign is required to significantly reduce the morbidity. However, the risk of spreading this transboundary disease to neighboring LSDV virus-free countries and regions of Asia, remains high enough. This article contains a summary of the available information about the spread of LSD in Asian part of Eurasia for the period of 1984 - February 2022. We are also discussing the latest available findings on the epidemiology of LSD and the methods currently used for the prevention and control of the LSDV.

Assessment of the control measures of the Category A diseases of the Animal Health Law: prohibitions in restricted zones and risk-mitigating treatments for products of animal origin and other materials

EFSA received a mandate from the European Commission to assess the effectiveness of prohibitions of certain activities in restricted zones, and of certain risk mitigation treatments for products of animal origin and other materials with respect to diseases included in the Category A list in the Animal Health Law (Regulation (EU) 2016/429). This opinion belongs to a series of opinions where other disease-specific control measures have been assessed. In this opinion, EFSA and the AHAW Panel of experts review the effectiveness of (i) prohibiting the movements of certain products, notably germinal products (semen, oocytes, embryos and hatching eggs), products of animal origin and animal by-products and feed of plant origin, hay and straw, and (ii) risk mitigation treatments for products of animal origin. In terms of semen, oocytes, embryos and hatching eggs, it was agreed that there was a lack of evidence particularly for embryos and oocytes reflected in a varying degree of uncertainty, whether these commodities could potentially contain the pathogen under consideration. The scenario assessed did not consider whether the presence of pathogen would lead to infection in the recipient animal. In terms of animal products, certain animal by-products and movement of feed of plant origin and straw, the assessment considered the ability of the commodity to transmit disease to another animal if exposed. For most pathogens, products were to some degree considered a risk, but lack of field evidence contributed to the uncertainty, particularly as potential exposure of ruminants to meat products is concerned. In terms of the risk mitigating treatments, recommendations have been made for several of these treatments, because the treatment description is not complete, the evidence is poor or inconclusive, or the evidence points to the treatment being ineffective.

Assessment of the control measures for category A diseases of Animal Health Law: Lumpy Skin Disease

EFSA received a mandate from the EC to assess the effectiveness of some of the control measures against diseases included in the Category A list according to Regulation (EU) 2016/429 on transmissible animal diseases ('Animal Health Law'). This opinion belongs to a series of opinions where these control measures are assessed, with this opinion covering the assessment of control measures for Lumpy Skin Disease (LSD). In this opinion, EFSA and the AHAW Panel of experts review the effectiveness of: i) clinical and laboratory sampling procedures, ii) monitoring period and iii) the minimum radius of the protection and surveillance zones, and the minimum length of time that measures should be applied in these zones. The general methodology used for this series of opinions has been published elsewhere; nonetheless, the transmission kernels used for the assessment of the minimum radius of the protection and surveillance zones are shown. Several scenarios for which these control measures had to be assessed were designed and agreed prior to the start of the assessment. The monitoring period was assessed as effective, and based on the transmission kernels available, it was concluded that the protection zone of 20 km radius and the surveillance zone of 50 km radius would comprise > 99% of the transmission from an affected establishment if transmission occurred. Recommendations provided for each of the assessed scenarios aim to support the European Commission in the drafting of further pieces of legislation, as well as for plausible ad hoc requests in relation to LSD.

Characterization of a Nigerian Lumpy Skin Disease Virus Isolate after Experimental Infection of Cattle

Lumpy skin disease virus (LSDV), together with sheeppox virus and goatpox virus, belong to the genus Capripoxvirus within the family Poxviridae. Collectively, they are considered the most serious poxvirus diseases of agricultural livestock. Due to their severe clinical course and consequent loss of production, as well as high mortality of naïve small and large ruminant populations, they are known to have a significant impact on the economy and global trade restrictions of affected countries. Therefore, all capripox diseases are classified as notifiable under the guidelines of the World Organization of Animal Health (OIE). Since the 1970s, several outbreaks of LSD have been recorded in Nigeria. Until now, only a little information on the virus strains leading to the reported outbreaks have been published, dealing mainly with the phylogenetic relationship of those strains and the description of field outbreaks. During the present study, we experimentally infected cattle with a low-passage Nigerian LSDV strain isolated from a skin sample of LSD positive cattle in Nigeria in 2018. Clinical, molecular and serological data indicate that this LSDV isolate is highly pathogenic in cattle since it induced a severe clinical course and approximately 33% mortality in naïve Holstein Friesian cattle after experimental infection.

Lumpy skin disease is expanding its geographic range: A challenge for Asian livestock management and food security

In recent years, lumpy skin disease virus has extended its geographical range outside of endemic sub-Saharan countries to the Middle East and Asia indicating transboundary spread. Recently, lumpy skin disease (LSD) outbreaks have been reported in Asian countries such as Bangladesh, India, China, Nepal, Bhutan, Vietnam, Myanmar, Sri Lanka, Thailand, Malaysia, Laos and for the first time and represent a cause of serious concern for their livestock and dairy industries. This report summarizes information on the recent outbreaks of LSD in southern Asia and emphasizes the threat it poses to neighbouring countries. Various strategies and actions needed to control outbreaks of this emerging disease in Asia are also suggested.

Review: Vaccines and Vaccination against Lumpy Skin Disease

The geographical distribution of lumpy skin disease (LSD), an economically important cattle disease caused by a capripoxvirus, has reached an unprecedented extent. Vaccination is the only way to prevent the spread of the infection in endemic and newly affected regions. Yet, in the event of an outbreak, selection of the best vaccine is a major challenge for veterinary authorities and farmers. Decision makers need sound scientific information to support their decisions and subsequent actions. The available vaccine products vary in terms of quality, efficacy, safety, side effects, and price. The pros and cons of different types of live attenuated and inactivated vaccines, vaccination strategies, and associated risks are discussed. Seroconversion, which typically follows vaccination, places specific demands on the tools and methods used to evaluate the effectiveness of the LSD vaccination campaigns in the field. We aimed to give a comprehensive update on available vaccines and vaccination against LSD, to better prepare affected and at-risk countries to control LSD and ensure the safe trade of cattle.

Emergence and transboundary spread of lumpy skin disease in South Asia

Lumpy skin disease (LSD) is an OIE notifiable, transboundary pox viral disease of livestock. LSD is an emerging disease severely affecting livestock economics. The zoonotic potential of the LSD virus has not been extensively studied and reported. In approximately 90 years, the virus dispersed to numerous world locations after its first emergence in Zambia. LSD virus emergence in South Asia prevailed among livestock (cattle and water buffalo) owners due to economic/financial losses. The estimate of the economic impact of LSD in the southern, eastern and southeastern countries suggested direct losses of livestock and production of approximately USD 1.45 billion. In 2019, nearly the same time, the disease was reported for the first time from many bordering countries, such as India, Nepal, China, and Bangladesh. In 2020, the LSD was also recorded in Bhutan, Sri Lanka, Bangladesh, Vietnam and Southeast China. In 2021, it further spread to new countries such as Thailand, Malaysia and Cambodia. Cattle affected with LSD show a characteristic nodular lesion or skin lump over the whole body and may occasionally be associated with systemic signs. Hematophagous arthropod-borne mechanical transmission is considered primary and the most common route; however, other transmission routes related to illegal animal trade have played a role in the emergence of LSD in countries otherwise/earlier free from it. Among serological diagnostic tests, OIE recommends virus neutralization as the standard gold test. Diagnosis in LSD-free countries requires virus isolation and further sequencing of the isolate. Control of LSD is possible by most of the measures applied for rapidly transmitting viral infection, including vaccination. LSD virus-specific vaccines are considered suitable to confer protection to cattle and buffalo over heterologous vaccines. In countries such as India, the lack of a specific policy for LSD at the time of the first onset of this disease, the high density of susceptible unvaccinated populations, unawareness among farmers, veterinarians and prevailing laws of no slaughter of cattle created a favourable situation of its spread to many states. Amid COVID-19, the whole world is in turmoil; the emergence of diseases such as LSD is further lowering the economy, and hence must be reviewed to save and sustain the backbone of the developing country's economy in Southeast Asia.

Transboundary Animal Diseases, an Overview of 17 Diseases with Potential for Global Spread and Serious Consequences

Animals provide food and other critical resources to most of the global population. As such, diseases of animals can cause dire consequences, especially disease with high rates of morbidity or mortality. Transboundary animal diseases (TADs) are highly contagious or transmissible, epidemic diseases, with the potential to spread rapidly across the globe and the potential to cause substantial socioeconomic and public health consequences. Transboundary animal diseases can threaten the global food supply, reduce the availability of non-food animal products, or cause the loss of human productivity or life. Further, TADs result in socioeconomic consequences from costs of control or preventative measures, and from trade restrictions. A greater understanding of the transmission, spread, and pathogenesis of these diseases is required. Further work is also needed to improve the efficacy and cost of both diagnostics and vaccines. This review aims to give a broad overview of 17 TADs, providing researchers and veterinarians with a current, succinct resource of salient details regarding these significant diseases. For each disease, we provide a synopsis of the disease and its status, species and geographic areas affected, a summary of in vitro or in vivo research models, and when available, information regarding prevention or treatment.

A review: Surveillance of lumpy skin disease (LSD) a growing problem in Asia

Lumpy skin disease (LSD) is a viral disease caused by lumpy skin disease virus (LSDV), a member of Capripoxvirus, genus of Poxviridae family. It is a transboundary infection of monetary significance that primarily affects water buffaloes and cattle. LSD was known to be once endemic in Saharan regions of Africa but later on reported in central Asian and neighboring countries of Pakistan like, India, Iran and China. It is a vector borne disease and arthropods are believed to be the main perpetrators. It is discernible by its high morbidity and low mortality. Characteristic lumps on skin and high fever are considered as major signs while reduced milk production, infertility, early embryonic death and anorexia are some of the salient clinical manifestations of the disease. Additionally, nodules on mucosa of oro-pharynx, udder, genitalia and rectum are usually observed on examination. This article summarizes LSD outbreaks across Asia during last fifteen years. It is a general consensus amongst the veterinary community that disease is endemic in Pakistan as it shares borders with India, Iran and China where recent outbreaks are reported. Historically Pakistan is free of LSD, however it is at high risk of a LSDV outbreak as neighboring regions are becoming endemic. Vaccination, strict quarantine measures, limited movement of livestock along with vector control could be effective for preventing the spread of the disease. This review aims to summarize the latest developments in the epidemiology of LSD with the focus on transboundary spread, possible emergence and economic implications on Pakistan.

Quantifying and Modeling the Acquisition and Retention of Lumpy Skin Disease Virus by Hematophagus Insects Reveals Clinically but Not Subclinically Affected Cattle Are Promoters of Viral Transmission and Key Targets for Control of Disease Outbreaks

Lumpy skin disease virus (LSDV) causes a severe systemic disease characterized by cutaneous nodules in cattle. LSDV is a rapidly emerging pathogen, having spread since 2012 into Europe and Russia and across Asia.

Lumpy skin disease virus (LSDV) is a vector-transmitted poxvirus that causes disease in cattle. Vector species involved in LSDV transmission and their ability to acquire and transmit the virus are poorly characterized. Using a highly representative bovine experimental model of lumpy skin disease, we fed four model vector species (Aedes aegypti, Culex quinquefasciatus, Stomoxys calcitrans, and Culicoides nubeculosus) on LSDV-inoculated cattle in order to examine their acquisition and retention of LSDV. Subclinical disease was a more common outcome than clinical disease in the inoculated cattle. Importantly, the probability of vectors acquiring LSDV from a subclinical animal (0.006) was very low compared with that from a clinical animal (0.23), meaning an insect feeding on a subclinical animal was 97% less likely to acquire LSDV than one feeding on a clinical animal. All four potential vector species studied acquired LSDV from the host at a similar rate, but Aedes aegypti and Stomoxys calcitrans retained the virus for a longer time, up to 8 days. There was no evidence of virus replication in the vector, consistent with mechanical rather than biological transmission. The parameters obtained in this study were combined with data from studies of LSDV transmission and vector life history parameters to determine the basic reproduction number of LSDV in cattle mediated by each of the model species. This reproduction number was highest for Stomoxys calcitrans (19.1), followed by C. nubeculosus (7.1) and Ae. aegypti (2.4), indicating that these three species are potentially efficient transmitters of LSDV; this information can be used to inform LSD control programs.

IMPORTANCE Lumpy skin disease virus (LSDV) causes a severe systemic disease characterized by cutaneous nodules in cattle. LSDV is a rapidly emerging pathogen, having spread since 2012 into Europe and Russia and across Asia. The vector-borne nature of LSDV transmission is believed to have promoted this rapid geographic spread of the virus; however, a lack of quantitative evidence about LSDV transmission has hampered effective control of the disease during the current epidemic. Our research shows subclinical cattle play little part in virus transmission relative to clinical cattle and reveals a low probability of virus acquisition by insects at the preclinical stage. We have also calculated the reproductive number of different insect species, therefore identifying efficient transmitters of LSDV. This information is of utmost importance, as it will help to define epidemiological control measures during LSDV epidemics and of particular consequence in resource-poor regions where LSD vaccination may be less than adequate.

Lumpy skin disease, an emerging transboundary viral disease: A review

Lumpy skin disease is an emerging bovine viral disease, which is endemic in most African countries and some Middle East ones, and the elevated risk of the spread of disease into the rest of Asia and Europe should be considered. The recent rapid spread of disease in currently disease-free countries indicates the importance of understanding the limitations and routes of distribution. The causative agent, Capripoxvirus, can also induce sheeppox and goatpox. The economic significance of these diseases is of great concern, given that they threaten international trade and could be used as economic bioterrorism agents. The distribution of capripoxviruses seems to be expanding due to limited access to effective vaccines and poverty within farming communities. This is largely due to the economic effects of the Covid-19 pandemic and the imposition of crippling sanctions in endemic regions, as well as an increase in the legal and illegal trade of live animals and animal products, and also global climate change. The present review is designed to provide existing information on the various aspects of the disease such as its clinicopathology, transmission, epidemiology, diagnosis, prevention and control measures, and the potential role of wildlife in the further spread of disease.

Development of a Safe and Highly Efficient Inactivated Vaccine Candidate against Lumpy Skin Disease Virus

Capripox virus (CaPV)-induced diseases (lumpy skin disease, sheeppox, goatpox) are described as the most serious pox diseases of livestock animals, and therefore are listed as notifiable diseases under guidelines of the World Organisation for Animal Health (OIE). Until now, only live-attenuated vaccines are commercially available for the control of CaPV. Due to numerous potential problems after vaccination (e.g., loss of the disease-free status of the respective country, the possibility of vaccine virus shedding and transmission as well as the risk of recombination with field strains during natural outbreaks), the use of these vaccines must be considered carefully and is not recommended in CaPV-free countries. Therefore, innocuous and efficacious inactivated vaccines against CaPV would provide a great tool for control of these diseases. Unfortunately, most inactivated Capripox vaccines were reported as insufficient and protection seemed to be only short-lived. Nevertheless, a few studies dealing with inactivated vaccines against CaPV are published, giving evidence for good clinical protection against CaPV-infections. In our studies, a low molecular weight copolymer-adjuvanted vaccine formulation was able to induce sterile immunity in the respective animals after severe challenge infection. Our findings strongly support the possibility of useful inactivated vaccines against CaPV-infections, and indicate a marked impact of the chosen adjuvant for the level of protection.

Potential link of single nucleotide polymorphisms to virulence of vaccine-associated field strains of lumpy skin disease virus in South Africa

South Africa is endemic for lumpy skin disease and is therefore reliant on various live attenuated vaccines for the control and prevention of the disease. In recent years, widespread outbreaks of vaccine‐like strains of lumpy skin disease virus (LSDV) were reported internationally, leading to an increase in the generation of full genome sequences from field isolates. In this study, the complete genomes of six LSDVs submitted during active outbreaks in the 1990s in South Africa were generated. Based on phylogenetic analysis, the six viruses clustered with vaccine strains in LSDV Subgroup 1.1 and are subsequently referred to as vaccine‐associated. The genetic differences between the phenotypically distinct vaccine and vaccine‐associated strains were 67 single nucleotide polymorphisms (SNPs). This study characterized the location and possible importance of each of these SNPs in their role during virulence and host specificity.

A review: Lumpy skin disease and its emergence in India

Lumpy skin disease (LSD) is a viral disease caused by lumpy skin disease virus (LSDV), a member of Capripoxvirus genus of Poxviridae family. It is a transboundary disease of the economic importance affecting cattle and water buffaloes. The disease is transmitted by arthropod vectors and causes high morbidity and low mortality. LSD has recently been reported first time in India with 7.1% morbidity among cattle. Generally, fever, anorexia, and characteristic nodules on the skin mucous membrane of mouth, nostrils, udder, genital, rectum, drop in milk production, abortion, infertility and sometimes death are the clinical manifestations of the disease. The disease is endemic in African and Middle East countries but has started spreading to Asian and other countries. It has been recently reported from China and Bangladesh sharing borders with India. We have summarized occurrence of LSD outbreaks in last 10 years in Asian countries for the first time. In India, currently epidemiological status of the disease is unknown. Vaccination along with strict quarantine measures and vector control could be effective for preventing the spread of the disease. This review aims to summarise the latest developments in the epidemiology with the focus on transboundary spread, aetiology and transmission, clinical presentations, diagnostics and management of the disease.

Minimum Infective Dose of a Lumpy Skin Disease Virus Field Strain from North Macedonia

Infection with Lumpy Skin Disease virus (LSDV), as well as infections with other Capripox virus species, are described as the most severe pox diseases of production animals and are therefore listed as notifiable diseases under the guidelines of the World Organization for Animal Health (OIE). To our knowledge there is only a single study examining dose dependency, clinical course, viremia, virus shedding, as well as serological response following experimental LSDV “Neethling” inoculation. Here, we inoculated cattle with four different doses of LSDV strain “Macedonia2016”, a recently characterized virulent LSDV field strain, and examined clinical symptoms, viremia, viral shedding, and seroconversion. Interestingly, around 400 cell culture infectious dose₅₀ (CCID₅₀) of LSDV-“Macedonia2016” were sufficient to induce generalized Lumpy Skin Disease (LSD) in two out of six cattle but with a different incubation time, whereas the other animals of this group showed only a mild course of LSD. However, differences in incubation time, viral loads, serology, and in the clinical scoring could not be observed in the other three groups. In summary, we concluded that experimental LSDV infection of cattle with an infectious virus titer of 10⁵ to 10⁶ CCID₅₀/_mL of “Macedonia2016” provides a robust and sufficient challenge model for future studies.

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

Lumpy skin disease (LSD) caused by lumpy skin disease virus (LSDV) inflicts significant economic losses in cattle production with impact on livelihoods of smallholders. This study reports the first occurrence of LSD in cattle in India and analyses epidemiological and genetic characterization data from LSD outbreaks in five districts of Odisha state in August 2019. In all, 182 of 2,539 cattle were affected with an apparent morbidity rate of 7.1% and no mortality. Out of 102 samples from 60 LSD suspected and 17 asymptomatic in-contact cattle tested, 29.87% cattle were positive by capripoxvirus generic PCR and 37.66% were positive by LSDV real-time PCR. All the in-contact cattle tested were negative for LSDV. Among affected cattle, LSDV genome was detected more in scabs (79.16%) than blood (31.81%) and frozen bull semen (20.45%). Differential diagnosis by PCR was negative for pseudo-LSD, buffalopox, cowpox, pseudo-cowpox and bovine papular stomatitis. Five selected PCR and real-time PCR-positive LSDV DNA were sequenced in three genomic regions, P32 (LSDV074), F (LSDV117) and RPO30 (LSDV036). Phylogenetic analysis based on partial P32 and F gene sequences and complete RPO30 gene sequences showed that all the five Indian LSDV strains were identical and clustered with other field strains of LSDV circulating globally. However, the F and RPO30 gene sequence analyses revealed that Indian LSDV strains are genetically closer to the South African NI2490/KSGP-like strains than the strains detected in Europe, which was rather surprising. The present study established the existence of LSDV in India and involvement of LSDV field strains in the outbreaks. Additionally, we provided evidence of LSDV shedding in semen of naturally infected bulls. Further studies are required to determine the source of LSD introduction, extent of spread, modes of transmission and impact on dairy cattle production in India and effective control measures must be undertaken urgently.

Emergence of a new lumpy skin disease virus variant in Kurgan Oblast, Russia, in 2018

In this paper, we report the resurgence of lumpy skin disease (LSD) in Kurgan Oblast, Russia, in 2018. The majority of the outbreaks were silent with no mortality and congregated within an area with a radius of about 30 km located 1-50 km away from the national border with Kazakhstan. Following primary molecular diagnosis, LSD virus (LSDV) isolates were analyzed using a panel of PCR assays targeting different genetic loci, namely, LSD008 (vaccine), LSDV126 (field), and GPCR (vaccine and field), for differentiation and genotype assignment. All isolates were positive for the vaccine genotype of GPCR and negative for the other field targets tested. A PCR assay with melt curve analysis utilizing LSD008, developed in this work, indicated that the strains melted with a profile similar to those of field strains. Surprisingly, sequence analysis of the RPO30 and GPCR genes aligned the Kurgan/2018 isolate with KSGP O-240 at the GPCR locus, but with Saratov/2017 at the RPO30 locus. The latter cluster forms an association with a sub-cluster of the field strains comprising the South African KSGP O-240 strain and NI-2490 strain. Due to these incongruent phylogenetic patterns, the sequences of three additional loci ORF19 (Kelch-like protein), ORF52 (putative transcriptional elongation factor), and ORF87 (mutT motif protein) were investigated. Phylogenetic analysis of these additional loci placed the strain Kurgan/2018 in either vaccine or field groups, strongly suggesting a novel recombinant profile. This is another piece of evidence exposing the potential for recombination in capripoxviruses and the ignored danger of using live homologous vaccines against LSD. The necessity to revise the PCR-based strategy differentiating infected from vaccinated animals is discussed. The potential scenarios of incursion and the contribution of the KSGP/NI-2490-like strain to the emergence of the recently identified vaccine-like recombinant are discussed.

Morphological Characteristics of Skin Lesions in Cattle Naturally Infected with Lumpy Skin Disease Virus in Serbia

Lumpy skin disease (LSD) is a disease of cattle and domestic buffaloes caused by Capripoxvirus which can lead to significant economic losses. Until several years ago it was limited to Africa and the Middle East, but recently it was reported in Turkey (2013), Greece (2015), and in 2016 it spread to Bulgaria, North Macedonia, Albania, Montenegro and Serbia. The aim of this study was to determine the microscopic lesions in the skin of naturally infected animals, highlight their features and compare them to the findings of other authors. Gross lesions in the skin of cattle infected with Lumpy skin disease virus (LSDV) were manifested in the form of skin nodules which were round, raised, clearly circumscribed, firm and randomly distributed in the whole skin including the vulva and udder. Histopathological lesions included degeneration of epithelial cells, hyperkeratosis, spongiosis, and acanthosis present in 85.88%, 81.18%, 84.71%, and 80.0% of samples, respectively. Intracytoplasmic inclusion bodies were noted in keratinocytes of the stratum spinosum in 56.47% of samples, and in hair follicle cells and sebaceous glands epithelial cells in 45.88% of samples. Cutaneous lesions were in the form of inflammatory infiltrate present in the dermis and subcutis in 97.65% of samples. Since there are only a few literature data in this field, this study expands the knowledge relating to morphological alterations in LSD. Based on the characteristic microscopic lesions described in the present study, histopathology should be considered as a very useful method for the diagnosis of LSD.

Epizootic features and control measures for lumpy skin disease in south-east Serbia in 2016

Lumpy skin disease (LSD) is an infectious disease of cattle caused by virus of the Capripoxvirus genus (LSDV), family Poxviridae. Until 2015, it had not appeared in the Balkans. In June 2016, LSD spread throughout Serbia. This study analyses the first LSD occurrence, epizootic features, applied diagnostic procedures and control measures in five districts in south-east Serbia (Pcinja, Jablanica, Pirot, Toplica and Nisava). In total, there were 225 LSD outbreaks reported in Serbia, out of which 189 (84%) were located in the study area. The highest number of outbreaks was registered in Pcinja district (169), where LSD was first registered. The median distance and time between the nearest previous outbreak sites were calculated (4.32 km and 9 days). The median altitude of outbreak locations was 992 m with more than 90% above 500 m (p ≤ 0.001). The average herd morbidity rate in the study area was 13.6% and the herd mortality rate was recorded only in Pcinja (0.5%) and Jablanica (1.6%) districts. Samples taken from the cattle suspected to LSD were subjected to real time PCR analysis. Out of 233 samples tested for LSDV 132 (56.7%) were positive. The LSDV genome was identified in skin nodules (85.4%), blood (72.7%) and nasal swabs (62.5%). Phylogenetic analysis indicated that the LSDV strain circulating in Serbia fell within the cluster of field LSDV found worldwide. In response to the LSD epizootic, animal trade and movement were prohibited, complete stamping out, disinfection, disinsection and an entire bovine population vaccination using the homologous Neethling live attenuated vaccine (OBP, South Africa) were conducted. A month and a half after the completion of the vaccination campaign, the LSD epizootic was stopped, and no new cases have been reported since.

Transmission of lumpy skin disease virus: A short review

Lumpy skin disease (LSD) is a viral transboundary disease endemic throughout Africa and of high economic importance that affects cattle and domestic water buffaloes. Since 2012, the disease has spread rapidly and widely throughout the Middle Eastern and Balkan regions, southern Caucasus and parts of the Russian Federation. Before vaccination campaigns took their full effect, the disease continued spreading from region to region, mainly showing seasonal patterns despite implementing control and eradication measures. The disease is capable of appearing several hundred kilometers away from initial (focal) outbreak sites within a short time period. These incursions have triggered a long-awaited renewed scientific interest in LSD resulting in the initiation of novel research into broad aspects of the disease, including epidemiology, modes of transmission and associated risk factors. Long-distance dispersal of LSDV seems to occur via the movement of infected animals, but distinct seasonal patterns indicate that arthropod-borne transmission is most likely responsible for the swift and aggressive short-distance spread of the disease. Elucidating the mechanisms of transmission of LSDV will enable the development of more targeted and effective actions for containment and eradication of the virus. The mode of vector-borne transmission of the disease is most likely mechanical, but there is no clear-cut evidence to confirm or disprove this assumption. To date, the most likely vectors for LSDV transmission are blood-sucking arthropods such as stable flies (Stomoxys calcitrans), mosquitoes (Aedes aegypti), and hard ticks (Rhipicephalus and Amblyomma species). New evidence suggests that the ubiquitous, synanthropic house fly, Musca domestica, may also play a role in LSDV transmission, but this has not yet been tested in a clinical setting. The aim of this review is to compile and discuss the earlier as well as the most recent research data on the transmission of LSDV.

Effect of using frozen-thawed bovine semen contaminated with lumpy skin disease virus on in vitro embryo production

Lumpy skin disease (LSD) is an important transboundary animal disease of cattle with significant economic impact because of the implications for international trade in live animals and animal products. LSD is caused by a Capripoxvirus, LSD virus (LSDV), and results in extensive hide and udder damage, fever and pneumonia. LSDV can be shed in semen of infected bulls for prolonged periods and transmitted venereally to cows at high doses. This study examined the effects of LSDV in frozen-thawed semen on in vitro embryo production parameters, including viral status of media and resulting embryos. Bovine oocytes were harvested from abattoir-collected ovaries and split into three experimental groups. After maturation, the oocytes were fertilized in vitro with frozen-thawed semen spiked with a high (HD) or a lower (LD) dose of LSDV, or with LSDV-free semen (control). Following day 7 and day 8 blastocyst evaluation, PCR and virus isolation were performed on all embryonic structures. After completing sufficient replicates to reach 1,000 inseminated oocytes, further in vitro fertilization (IVF) runs were performed to provide material for electron microscopy (EM) and embryo washing procedures. Overall, in vitro embryo yield was significantly reduced by the presence of LSDV in frozen-thawed semen, irrespective of viral dose. When semen with a lower viral dose was used, significantly lower oocyte cleavage rates were observed. LSDV could be detected in fertilization media and all embryo structures, when higher doses of LSDV were present in the frozen-thawed semen used for IVF. Electron microscopy demonstrated LSDV virions inside blastocysts. Following the International Embryo Transfer Society washing procedure resulted in embryos free of viral DNA; however, this may be attributable to a sampling dilution effect and should be interpreted with caution. Further research is required to better quantify the risk of LSDV transmission via assisted reproductive procedures.

Determination of lumpy skin disease virus in bovine meat and offal products following experimental infection

Lumpy skin disease (LSD) has recently expanded its range northwards to include the Balkans, Turkey and Russia. Because there was no solid evidence conclusively verifying the transmission mechanism in the field and LSDV viraemic animals with overt and asymptomatic presentation of disease and their products may represent a risk as an indirect transmission pathway. In this work, we used PCR positivity and infectivity in clinical and subclinical infection to evaluate the safety of meat and offal products from cows infected with the virulent LSDV strain Russia/Dagestan/2015. At day 21 post infection, seven of the 12 animals developed the generalized disease, and four animals became subclinically infected without apparent clinical signs. Upon examination and necropsy, the animals with the generalized disease had skin lesions; noticeably enlarged lymph nodes; and lesions in the lungs, trachea and testicles; whereas subclinically ill animals exhibited only enlarged lymph nodes and fever. For both disease presentations, testing of skeletal meat by PCR and virus isolation showed that the skeletal meat did not contain live virus or viral genome, whereas in cattle with generalized disease, meat with gross pathology physically connected under the site of a skin lesion was positive for the live virus. In subclinical infection, only enlarged lymph nodes carried the infectious virus, while the other internal organs tested in both types of disease manifestation were negative except for the testicles. Overall, our findings demonstrate that clinically and subclinically infected animals are reservoirs of live LSDV in lymph nodes and testicles, whereas deep skeletal meat in both types of infection do not carry live virus and the risk of transmission through this product seems very low. The detection of LSDV in testicular tissues in subclinically ill animals is concerning because of the potential to spread infection through contaminated semen. This aspect requires reconsideration of surveillance programmes to identify these Trojan horses of LSDV infection.

Spatial analysis of lumpy skin disease in Eurasia-Predicting areas at risk for further spread within the region

Data from affected lumpy skin disease (LSD) locations between July 2012 and September 2018 in the Balkans, Caucasus, and Middle East were retrieved from FAO's Global Animal Disease Information System (EMPRES-i) from the European Commission's Animal Disease Notification System (ADNS) and completed with data from the official veterinary services of some countries. During this period, a total of 7,593 locations from 22 countries were affected. Within this period, over 46,000 cattle were clinically affected by LSD, 3,700 animals died and 17,500 were slaughtered due to culling policies to stop the spread of the disease. Most outbreaks occurred in 2016, between the months of May and November. The affected region was divided into a grid of 10 × 10 km cells and we fit a spatial regression model to analyse the association between the reported LSD outbreaks and climatic variables, land cover, and cattle density. The results showed big differences in the odds of being LSD positive due to the type of land cover: the odds of a cell being LSD positive was increased in areas mostly covered with croplands, grassland, or shrubland. The odds was also increased for higher cattle density, as well as areas with higher annual mean temperature and higher temperature diurnal range. The resulting model was utilized to predict the LSD risk in neighbouring unaffected areas in Europe, the Caucasus, and Central Asia, identifying several areas with high risk of spread. Results from this study provide useful information for the design of surveillance and awareness systems, and preventive measures, e.g., vaccination programmes.

Review: Risks of disease transmission through semen in cattle

The purpose of this paper is to review scientific evidence concerning pathogens that could potentially be transmitted via bovine semen. As a result of a careful analysis of the characteristics of infections that may cause transmission of disease through semen, effective control procedures can be identified that provide minimal constraint to the introduction of new bulls into herds for natural breeding and importation of valuable novel genetics through artificial insemination. The potential for transmission through bovine semen and corresponding effective control procedures are described for bovine herpesvirus 1, bovine viral diarrhea virus, bovine leukemia virus, lumpy skin disease virus, bluetongue virus, foot-and-mouth disease virus, and Schmallenberg virus. Brief consideration is also provided regarding the potential for transmission via semen of Tritrichomonas foetus, Campylobacter fetus venerealis, Brucella abortus, Leptospira spp., Histophilus somni, Ureaplasma diversum, Mycobacterium avium subsp. paratuberculosis, Chlamydiaceae, Mycobacterium bovis, Coxiella burnetii, Mycoplasma mycoides ssp. mycoides and Neospora caninum. Thoughtful and systematic control procedures can ensure the safety of introducing new bulls and cryopreserved semen into cattle production systems.

Review: Capripoxvirus Diseases: Current Status and Opportunities for Control

Lumpy skin disease, sheeppox and goatpox are high-impact diseases of domestic ruminants with a devastating effect on cattle, sheep and goat farming industries in endemic regions. In this article, we review the current geographical distribution, economic impact of an outbreak, epidemiology, transmission and immunity of capripoxvirus. The special focus of the article is to scrutinize the use of currently available vaccines to investigate the resource needs and challenges that will have to be overcome to improve disease control and eradication, and progress on the development of safer and more effective vaccines. In addition, field evaluation of the efficacy of the vaccines and the genomic database available for poxviruses are discussed.

Emergence of Lumpy Skin Disease in Greece, 2015

Lumpy skin disease was first reported in the EU, Greece, in August 2015. Until the end of December 2015, six regional units have been affected in northern Greece and the island of Limnos. This article presents the epidemiological situation, the diagnosis, the control measures including emergency vaccination and the preliminary conclusions from the experience gained.

Seroprevalence of Rift Valley fever and lumpy skin disease in African buffalo (Syncerus caffer) in the Kruger National Park and Hluhluwe-iMfolozi Park, South Africa

Rift Valley fever and lumpy skin disease are transboundary viral diseases endemic in Africa and some parts of the Middle East, but with increasing potential for global emergence. Wild ruminants, such as the African buffalo (Syncerus caffer), are thought to play a role in the epidemiology of these diseases. This study sought to expand the understanding of the role of buffalo in the maintenance of Rift Valley fever virus (RVFV) and lumpy skin disease virus (LSDV) by determining seroprevalence to these viruses during an inter-epidemic period. Buffaloes from the Kruger National Park (n = 138) and Hluhluwe-iMfolozi Park (n = 110) in South Africa were sampled and tested for immunoglobulin G (IgG) and neutralising antibodies against LSDV and RVFV using an indirect enzyme-linked immunosorbent assay (I-ELISA) and the serum neutralisation test (SNT). The I-ELISA for LSDV and RVFV detected IgG antibodies in 70 of 248 (28.2%) and 15 of 248 (6.1%) buffaloes, respectively. Using the SNT, LSDV and RVFV neutralising antibodies were found in 5 of 66 (7.6%) and 12 of 57 (21.1%), respectively, of samples tested. The RVFV I-ELISA and SNT results correlated well with previously reported results. Of the 12 SNT RVFV-positive sera, three (25.0%) had very high SNT titres of 1:640. Neutralising antibody titres of more than 1:80 were found in 80.0% of the positive sera tested. The LSDV SNT results did not correlate with results obtained by the I-ELISA and neutralising antibody titres detected were low, with the highest (1:20) recorded in only two buffaloes, whilst 11 buffaloes (4.4%) had evidence of co-infection with both viruses. Results obtained in this study complement other reports suggesting a role for buffaloes in the epidemiology of these diseases during inter-epidemic periods.

Characterization of sheep pox virus vaccine for cattle against lumpy skin disease virus

Lumpy skin disease is of significant economic impact for the cattle industry in Africa. The disease is currently spreading aggressively in the Near East, posing a threat of incursion to Europe and Asia. Due to cross-protection within the Capripoxvirus genus, sheep pox virus (SPPV) vaccines have been widely used for cattle against lumpy skin disease virus (LSDV). In the Middle East and the Horn of Africa these vaccines have been associated with incomplete protection and adverse reactions in cattle post-vaccination. The present study confirms that the real identity of the commonly used Kenyan sheep and goat pox vaccine virus (KSGP) O-240 is not SPPV but is actually LSDV. The low level attenuation of this virus is likely to be not sufficient for safe use in cattle, causing clinical disease in vaccinated animals. In addition, Isiolo and Kedong goat pox strains, capable of infecting sheep, goats and cattle are identified for potential use as broad-spectrum vaccine candidates against all capripox diseases.