First detection of Lumpy Skin Disease virus in Tunisia

BackgroundLumpy Skin Disease (LSD) is endemic in sub-Saharan countries and is currently a global threat to the cattle industry. Information on the circulating Capripoxvirus lumpyskinpox, formerly known as Lumpy Skin Disease Virus (LSDV), and other poxviruses infecting cattle is very scant in Tanzania. The current study aimed to confirm and characterize LSDV and other poxviruses infecting cattle, from LSD suspected outbreaks in Tanzania.MethodsA total of 24 samples were collected from four LSD suspected outbreaks reported in Tanzania between February and May 2023. Samples were screened for LSDV genome by real-time PCR and then subjected to a high-resolution multiplex melting (HRM) assay where 10 samples were positive for Capripoxvirus (CaPV) and one sample was Parapoxvirus (PPV) positive. Four LSDV genes; RPO30, GPCR, EEV glycoprotein and B22R and the partial B2L gene of PPVs were analyzed.ResultsAll targeted LSDV genes from the Tanzanian isolates showed 100% similarity and isolates clustered with commonly circulating LSDV field isolates. Furthermore, the single nucleotide polymorphism (SNP) at position 240 (A-> G) of the EEV gene differentiates the Tanzanian LSDVs from the group of ancient Kenyan LSDV isolates while the B22R sequences of the Tanzanian LSDV isolates differed from the LSDV Neethling and LSDV KSGP-0240 derived vaccines. Sequence analysis of the partial B2L gene of the Tanzanian parapoxvirus bovinestomatitis, formerly known as Bovine papular stomatitis virus (BPSV) showed a different BPSV strain circulating compared to publicly available sequences.ConclusionThese findings confirm the presence of LSDV in Tanzania, which suggesting the need for establishing an effective control program and continuous monitoring. The presence of a typical profile for Tanzania BPSV is an indication that, although never reported before, BPSV is established in the country therefore this virus should be included in the differential diagnosis of LSDV.

Lumpy skin disease (LSD) is a highly contagious disease in bovine animals. An outbreak of LSD can cause devastating economic losses to the cattle industry. To investigate the distribution characteristics of historical LSD epidemics, LSD was divided into four phases for directional distribution analysis based on trends in epidemic prevalence. Ecological niche models were developed for LSD as well as for two vectors (Stomoxys calcitrans and Aedes aegypti), and global predictive maps were generated for the probability of LSD occurrence and the potential distribution of the two LSD vectors. The models had good predictive performance (the AUC values were 0.894 for the LSD model, 0.911 for the S. calcitrans model, and 0.950 for the A. aegypti model). The LSD combined vector prediction map was generated by combining the distribution maps of Stomoxys calcitrans and Aedes aegyptiwith fuzzy overlay tool in ArcGIS. The LSD combined vector prediction map was combined with the LSD prediction map to generate the LSD vector transmission risk map. The eastern and northwestern regions of North America, the eastern and northern regions of South America, the central and southern regions of Africa, the southern region of Europe, the northwestern and southeastern regions of Asia, and the eastern region of Australia were predicted to provide suitable environmental conditions for the occurrence of LSD. Cattle density, buffalo density, and bio2 (mean diurnal range) were identified as key variables for the occurrence of LSD. The findings of this study can be useful to policymakers in developing and implementing preventive measures of LSD for the health of cattle and the cattle industry.

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 (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.

Lumpy skin disease (LSD) is WOAH listed transboundary disease of cattle with high economic impact which threaten the global cattle industry. The disease was first diagnosed in Zambia in 1929 and the first outbreak in Tanzania was in 1981. LSD is regarded endemic in sub-Saharan countries. However, the community knowledge, attitude and practice (KAP) towards LSD in Tanzania is poorly understood. This cross-sectional study was conducted in Tanga and Pwani region between December 2022 and February 2023 to assess KAP towards LSD. A questionnaire tool was used to collect information from116 herds/households. Questionnaire was administered by face-to-face. Data analysis was done using descriptive statistic and univariate logistic regression model. In this study, it was found that majority of the respondents were aware of LSD occurrence (86.93%, CI=79.40-92.51) and over half of the respondents 54.78% (CI=45.23-64.04) had past LSD experience in their herds. However, our study revealed limited knowledge on LSD sign, associated losses, transmission control and on the role of vectors in LSD epidemiology. Majority of the respondent believed LSD has impact (86.09%, CI=78.39-91.83) and believe cattle are at risk (78.26%, CI=69.60-85.41). Moreover, respondents believed vaccine is important in LSD control (70.26%, CI=69.60-85.41). Nevertheless, majority believed they had limited access to vaccine. Respondent age, herd size, district, role in the households, main source of income, time in livestock farming, cattle type and past experience on LSD occurrence appeared to influence both the knowledge and attitude towards LSD in Tanga and Pwani regions.

Lumpy skin disease (LSD) is a contagious viral disease that has a significant impact on the cattle and buffalo agricultural industries. The use of live attenuated LSD virus (LSDV) vaccines (LAVs) is the most efficient method of disease prevention. However, it is well recognized that LAVs might result in viral mutation that could enhance viral infectivity or virulence. The goal of this research was to monitor the changes in genetic characteristics of LSDV in cattle after vaccination in Thailand. Five LSDV DNA samples from five different regions of Thailand including North, Northeast, West, Central, and South were selected. All samples came from non-vaccinated animals that developed LSD clinical signs after vaccination with the LAVs in each area. The samples were examined using real-time polymerase chain reaction (PCR) targeting the p32 gene and the whole genome sequences were analyzed. The genomes were compared to LSDV / Thailand / Yasothon / 2021, a recombinant LSDV strain discovered during the early stage of the outbreak in Northeast Thailand. Single nucleotide polymorphisms (SNPs), amino acid changes, and affected proteins were analyzed. The study discovered that following immunization in the area, LSDVs from Chiang Mai (North), Khon Kaen (Northeast), and Nakhon Pathom (Central) differed from the Yasothon isolate. Open reading frame (ORF) 032 Poly (A) polymerase large subunit, ORF094 virion core protein, and ORF133 DNA ligase-like protein, as well as virulence and host range genes; ORF144 Kelch-like protein and ORF148 Ankyrin-like protein had mutations, while the genomic sequences of Prachuap Khiri Khan (West) and Trang (South) isolates are 100% identical to the Yasothon virus. Mutations occurred in LSDV genomes from the North, Northeast, and Central regions following immunization. As a result, viral genetics should be examined on an annual basis for effective diagnosis and control of the disease.

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.

Lumpy skin disease (LSD) of cattle is a highly contagious viral skin disease causing sever economic losses. In Egypt, Protection of cattle against LSD was carried out using sheep poxvirus vaccines. In the present study, confirmative identification of previously isolated lumpy skin disease virus (LSDV) and commonly used sheep poxvirus (SPPV) vaccine (RM65 strain) nucleic acids was carried out by conventional polymerase chain reaction (PCR) and dot blot hybridization (DBH) depending on attachment protein gene (192 bp) of capripoxviruses. Differentiation between this LSDV isolate and SPPV vaccine (RM65 strain) was performed via PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and real time-PCR melting curve analysis depending on 390 bp genome fragment in which EcoRV sites is present in case of SPPV and absent in LSDV. Therefore, the amplified 390 bp genome fragment was digested by EcoRV in case of SPPV and not digested in LSDV isolate. Also, real time-PCR melting curve analysis revealed that melting temperature (Tm) of LSDV isolate was 78°C where Tm of SPPV vaccine was 76 °C. from this study, we concluded that PCR-RFLP and real time-PCR melting curve analysis could be used to differentiate between cattle infected with LSDV and those vaccinated with SPPV vaccine.

Lumpy skin disease (LSD) is a highly contagious viral disease in cattle caused by lumpy skin disease virus (LSDV), which belongs to the genus Capripoxvirus (CaPVs) within the family Poxviridae. Since its first outbreak in China in August 2019, LSD has spread widely across mainland China, posing significant threats to the cattle industry. This study aimed to isolate and identify a clinical strain of LSDV via Vero cells. Skin tissue samples from lump lesions were homogenized and inoculated onto cell cultures. After 7 passages, the inoculated cells exhibited typical cytopathic effects (CPEs). PCR amplification of the LSDV132 gene confirmed the presence of LSDV nucleic acid. In addition, quantitative PCR (qPCR) demonstrated a significant increase in viral copy number over time. Transmission electron microscopy (TEM) revealed typical brick-shaped viral particles. Furthermore, an indirect immunofluorescence assay (IFA) of infected Vero cells exhibiting CPEs produced a positive reaction with antiserum from cattle naturally infected with LSDV. Additionally, nucleotide similarity analysis of 123 LSDV strains revealed a high degree of similarity (98.4%-100%) among different geographic lineages. Nucleotide sequencing and recombination analysis of the LSDV011 gene from LSDV/China/HB01/2020 revealed close similarity to Asian strains and revealed a recombination event. Furthermore, similarity plot analysis confirmed two genomic exchange sites at nucleotide positions 120 and 762 within the LSDV011 gene. Recombination events between 65 Asian LSDV strains and 13 goatpox virus (GTPV) strains have raised safety concerns regarding the use of attenuated goatpox vaccines, highlighting the need for novel and safer LSDV vaccines. In summary, this study successfully isolated a clinical LSDV strain, demonstrating its evolutionary status and providing crucial insights for LSD control in the cattle industry.

Potential mechanical transmission of Lumpy skin disease virus (LSDV) by the stable fly (Stomoxys calcitrans) through regurgitation and defecation

Lumpy skin disease (LSD) is an economically important emerging vector-borne viral disease of cattle caused by the LSD virus. The recent outbreak of LSD has severely affected the economy of the cattle industry in many countries, including Bangladesh. LSD was first reported in Zambia in 1929 and has occurred in most African countries and sporadically in the Middle East region. LSD has now become a threat to Europe and Asia. The current outbreak in Bangladesh occurred in the second half of 2019. LSD was first reported in Zambia in 1929 and has occurred in most African countries and sporadically in the Middle East region. LSD has now become a threat to Europe and Asia. The current outbreak in Bangladesh occurred in the second half of 2019. The present study was carried out based on 210 LSD virus affected cattle of different breeds in the Jhenaidah district of Bangladesh from September, 2019 to December, 2019 to investigate the epidemiology of lumpy skin disease. Data was collected directly from the animal owners and through physical observation of the affected cattle based on clinical signs of LSD. About 61% of affected cases were found in high mosquito/fly prevalence areas. Young, female, and crossbred cattle were found to be more susceptible to LSD as compared to the adult, male, and indigenous breeds of cattle, respectively. LSD was found to be more prevalent among cattle ≤ 24 months of age. About 57.6% (95% CI: 50.6–64.4) of cattle were affected where bush was present around the farm/herd. Public awareness and biosecurity measures around the cattle farm are important to minimize the vector population and prevent the spread of LSD. Over 80% of affected cattle required more than a month of recovery. The present study also reviewed the latest research findings on the epidemiology of LSD. It will provide readers with a promising idea about LSD, which will be useful in developing a plan for the prevention and control of this disease.

A viral disease known as lumpy skin disease (LSD) that infects cattle has recently become a danger to the global livestock industry. Capripoxvirus, which causes LSD, can contract through insect bites or through direct contact with infected animals. Cattle with the disease develop nodules on their skin, which reduce their ability to produce milk, cause them to lose weight, and eventually kill them. LSD significantly reduces milk production, which may decrease from 10% to 85%. Milk and meat sales have decreased by 60% to 70% in Karachi (Pakistan), as a result of LSD. Calves of all strains and ages are affected, although lactating cows and young cattle are more at risk. The bulk of LSD outbreaks occurs in hot, humid environments when a large percentage of insects that serve as vectors are active. LSD may be transmitted more quickly by wildlife. Nasal secretions, inappetence, fever, lachrymation with salivation, swollen lymph nodules, body weight loss, and sometimes death are all symptoms of LSD. Farmers and the cattle industry have suffered enormous financial losses because of the increase in LSD. Concerns regarding the disease's effects on human health have also been raised due to its zoonotic potential. Although there is no evidence that LSD may be transmitted to others, the risk still exists, especially for those with compromised immune systems. This article discusses the current knowledge of LSD, its clinical manifestations, transmission, and preventive measures. It also draws attention to the effects of LSD breakouts, including financial, social, and medical fallouts, on people's lives. The paper highlights the necessity of continuing research and surveillance to comprehend the illness better and create efficient controls to stop its spread.

Lumpy skin disease (LSD), a high-impact disease of cattle and water buffalo, is a direct threat to the European cattle industry. The causative agent is the lumpy skin disease virus (LSDV), an enveloped dsDNA virus which belongs to the family Poxviridae. Affected cattle present multiple cutaneous nodules that are characteristic of a LSDV infection. The case fatality rate of LSD is low, however affected animals suffer substantial production losses including weight loss and reduced milk production. On a wider scale, LSD is a high consequence transboundary disease with mandated export restrictions imposed on affected countries leading to substantial economic costs. Currently, there is no cure for LSDV infected cattle. Hence, mass vaccination is an important component in minimizing the spread of LSDV. There are only a handful of commercially available live attenuated vaccines in the current market. These vaccines vary in efficacy, quality, and safety, which leaves some scope for further development. This improvement is hampered by a poor understanding of the immunology of LSDV, particularly the protective immune mechanisms. In this project, we are investigating the immune response to LSDV with a focus on characterising the cell-mediated immune response. Peripheral blood mononuclear cells from LSDV immunised/infected cattle and flow cytometry assays are used to detect the production of IFN-γ by CD4+T-helper cells and CD8+cytotoxic T cells in response to live LSDV stimulation. Our goal is to improve understanding of the immune response to LSDV in order to develop effective vaccines and control programs in the future.

Screening and identification of LSDV-specific monoclonal antibodies to establish a double-antibody sandwich ELISA for distinguishing LSDV from SPPV and GTPV.

BackgroundPoxviruses within the Capripoxvirus, Orthopoxvirus, and Parapoxvirus genera can infect livestock, with the two former having zoonotic importance. In addition, they induce similar clinical symptoms in common host species, creating a challenge for diagnosis. Although endemic in the country, poxvirus infections of small ruminants and cattle have received little attention in Botswana, with no prior use of molecular tools to diagnose and characterize the pathogens.MethodsA high-resolution melting (HRM) assay was used to detect and differentiate poxviruses in skin biopsy and skin scab samples from four cattle, one sheep, and one goat. Molecular characterization of capripoxviruses and parapoxviruses was undertaken by sequence analysis of RPO30 and GPCR genes.ResultsThe HRM assay revealed lumpy skin disease virus (LSDV) in three cattle samples, pseudocowpox virus (PCPV) in one cattle sample, and orf virus (ORFV) in one goat and one sheep sample. The phylogenetic analyses, based on the RPO30 and GPCR multiple sequence alignments showed that the LSDV sequences of Botswana were similar to common LSDV field isolates encountered in Africa, Asia, and Europe. The Botswana PCPV presented unique features and clustered between camel and cattle PCPV isolates. The Botswana ORFV sequence isolated from goat differed from the ORFV sequence isolated from sheep.ConclusionsThis study is the first report on the genetic characterization of poxvirus diseases circulating in cattle, goats, and sheep in Botswana. It shows the importance of molecular methods to differentially diagnose poxvirus diseases of ruminants.