Case report: Lumpy skin disease in an endangered wild banteng (Bos javanicus) and initiation of a vaccination campaign in domestic livestock in Cambodia

Whole Genome Sequencing of Lumpy Skin Disease Virus from 2021-2023 in Eastern Eurasia Reveals No More Recombination Signals in the Circulating Pool of Strains

Having spanned thousands of kilometers from Africa through Europe, the Middle East, Central Asia through to the south eastern part of Eurasia in the recent decade, lumpy skin disease virus has now become entrenched in China, Thailand, Vietnam, and South Korea. In light of discovered findings on recombination, cluster 2.5 lineage strains are now dominant and continue to spread throughout Southeast Asia. To gain a better picture of the phylogenetic landscape in the field, whole genome sequencing of 11 LSDV isolates from Russia and Mongolia collected from 2021 to 2023 has been attempted to see the dynamics of recombination signals, as was shown for LSDV circulating in 2017-2019 in Russia and Kazakhstan. Deep sequencing performed direct from skin nodules along with data retrieved from Genbank provides the most recent update on molecular epidemiology of LSDV and demonstrates that no more mosaic variant of LSDV has been observed, and cluster 2.5 lineage is now the dominant lineage currently on the rise in the region with its own patterns of monophyletic evolution. These discoveries may help future investigations aimed at epidemiological surveillance and virus tracking in the context of currently identified lineages worldwide.

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

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

Infection, dissemination, and transmission of lumpy skin disease virus in Aedes aegypti (Linnaeus), Culex tritaeniorhynchus (Giles), and Culex quinquefasciatus (Say) mosquitoes

Lumpy skin disease virus (LSDV) is a transboundary viral disease in cattle and water buffaloes. Although this Poxvirus is supposedly transmitted by mechanical vectors, only a few studies have investigated the role of local vectors in the transmission of LSDV. This study examined the infection, dissemination, and transmission rates of LSDV in Aedes aegypti, Culex tritaeniorhynchus, and Culex quinquefasciatus following artificial membrane feeding of 102.7, 103.7, 104.7 TCID50/mL LSDV in sheep blood. The results demonstrated that these mosquito species were susceptible to LSDV, with Cx tritaeniorhynchus exhibiting significantly different characteristics from Ae. aegypti and Cx. quinquefasciatus. These three mosquito species were susceptible to LSDV. Ae. aegypti showed it as early as 2 days post-infection (dpi), indicating swift dissemination in this particular species. The extrinsic incubation period (EIP) of LSDV in Cx. tritaeniorhynchus and Cx. quinquefasciatus was 8 and 14 dpi, respectively. Ingestion of different viral titers in blood did not affect the infection, dissemination, or transmission rates of Cx. tritaeniorhynchus and Cx. quinquefasciatus. All rates remained consistently high at 8-14 dpi for Cx. tritaeniorhynchus. In all three species, LSDV remained detectable until 14 dpi. The present findings indicate that, Ae. aegypti, Cx. tritaeniorhynchus, and Cx. quinquefasciatus may act as vectors during the LSDV outbreak; their involvement may extend beyond being solely mechanical vectors.

Analysis of Acute Phase Response Using Acute Phase Proteins Following Simultaneous Vaccination of Lumpy Skin Disease and Foot-and-Mouth Disease

Since 2011, South Korea has implemented biannual vaccinations against foot-and-mouth disease (FMD) and recently, lumpy skin disease (LSD), to mitigate the spread of transboundary animal diseases. However, due to past adverse reactions, potentially linked to acute phase responses from FMD vaccinations, there is hesitancy among Korean livestock farmers regarding new strategies for simultaneous vaccinations against both FMD and LSD. This study was conducted to assess possible adverse reactions to the LSD vaccination by analyzing acute phase proteins (APPs) in three groups: cows vaccinated against FMD (G1-FMDV), LSD (G2-LSDV), and both (G3-FMDV/LSDV). In G1-FMDV, APP levels peaked on day 3 post-vaccination (p < 0.001) and returned to baseline. In G2-LSDV, APP levels increased gradually, peaking on day 10 post-vaccination. In G3-FMDV/LSDV, APP levels peaked on day 3 post-vaccination and remained high until day 10 (p < 0.001). These results indicate that LSD vaccines trigger a later immune response compared to FMD vaccines, possibly due to different adjuvants. Therefore, a longer follow-up period for monitoring adverse reactions to LSD vaccinations may be required to understand and mitigate potential risks.

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

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

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

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

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

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

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

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

Detection and Genome Sequencing of Lumpy Skin Disease Viruses in Wildlife Game Species in South Africa

Lumpy skin disease virus (LSDV) has recently undergone rapid spread, now being reported from more than 80 countries, affecting predominantly cattle and to a lesser extent, water buffalo. This poxvirus was previously considered to be highly host-range restricted. However, there is an increasing number of published reports on the detection of the virus from different game animal species. The virus has not only been shown to infect a wide range of game species under experimental conditions, but has also been naturally detected in oryx, giraffe, camels and gazelle. In addition, clinical lumpy skin disease has previously been described in springbok (Antidorcas marsupialis), an African antelope species, in South Africa. This report describes the characterization of lumpy skin disease virus belonging to cluster 1.2, from field samples from springbok, impala (Aepyceros melampus) and a giraffe (Giraffa camelopardalis) in South Africa using PCR, Sanger and whole genome sequencing. Most of these samples were submitted from wild animals in nature reserves or game parks, indicating that the disease is not restricted to captive-bred animals on game farms or zoological gardens. The potential role of wildlife species in the transmission and maintenance of LSDV is further discussed and requires continuing investigation, as the virus and disease may pose a serious threat to endangered species.

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

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