Common, Emerging, Vector-Borne and Infrequent Abortogenic Virus Infections of Cattle

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.

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.

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.

North American Arboviruses and White-Tailed Deer (Odocoileus virginianus): Associated Diseases and Role in Transmission

Background: Arboviral disease is of increasing concern to human and animal health professionals as emerging and re-emerging arboviruses are more frequently recognized. Wildlife species are known to play a role in the transmission and maintenance of arboviruses and infections can result in morbidity and mortality in wildlife hosts. Materials and Methods: In this review, we detail existing evidence of white-tailed deer (Odocoileus virginianus) as an important host to a diverse collection of arboviruses and evaluate the utility of this species as a resource to better understand the epidemiology of related viral diseases. Results: Relevant veterinary and zoonotic viral pathogens endemic to North America include epizootic hemorrhagic disease virus, bluetongue virus, orthobunyaviruses, vesicular stomatitis virus, Eastern equine encephalitis virus, West Nile virus, and Powassan virus. Exotic viral pathogens that may infect white-tailed deer are also identified with an emphasis on zoonotic disease risks. The utility of this species is attributed to the high degree of contact with humans and domestic livestock and evidence of preferential feeding by various insect vectors. Conclusions: There is mounting evidence that white-tailed deer are a useful, widely available source of information regarding arboviral circulation, and that surveillance and monitoring of deer populations would be of value to the understanding of certain viral transmission dynamics, with implications for improving human and domestic animal health.

Clinico-molecular diagnosis and characterization of bovine lumpy skin disease virus in Andhra Pradesh, India

Lumpy skin disease (LSD) is an emerging transboundary disease in India. In the recent past, Andhra Pradesh is experiencing outbreaks of LSD in several pockets with a severe economic impact on the farming community. The affected animals showed nodular lesions all over the body in severely affected cases, whereas the lesions were confined to the face, neck, jowl, back, udder, and scrotum in less affected cases. Young ones are highly susceptible to the disease than adults. The mortality was found to be more in young ones than adult cattle which might be due to subsequent secondary bacterial complications. Clinical samples like blood, serum, and tissues were collected randomly from affected animals from four different pockets of Andhra Pradesh. The tissue samples gave positive amplification in PCR targeting LSDV fusion protein gene (ORF 117) and yielded 472 bp product. Another gene specifically targeting ORF036 of LSDV also gave amplification in tissue samples with a product size of 606 bp. The representative samples from four different regions were sequenced for ORF 117 and 036 genes. The phylogeny of the sequenced products of ORF 117 showed more similarity with Kenya Neethling 2490 strain and Russian isolates of 2019. In addition, the phylogeny of ORF 036 showed the path of entry of the virus into the country and also to Andhra Pradesh. The isolates showed similarity with the isolates of India (Odisha), Bangladesh, Russia, Egypt, and Kenya. These studies paved way for the future perspective of developing a vaccine to control the disease.

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.

Shuni Virus Replicates at the Maternal-Fetal Interface of the Ovine and Human Placenta

Shuni virus (SHUV) is a neglected teratogenic and neurotropic orthobunyavirus that was discovered in the 1960s in Nigeria and was subsequently detected in South Africa, Zimbabwe, and Israel. The virus was isolated from field-collected biting midges and mosquitoes and shown to disseminate efficiently in laboratory-reared biting midges, suggesting that members of the families Culicidae and Ceratopogonidae may function as vectors. SHUV infections have been associated with severe neurological disease in horses, a variety of wildlife species, and domesticated ruminants. SHUV infection of ruminants is additionally associated with abortion, stillbirth, and congenital malformations. The detection of antibodies in human sera also suggests that the virus may have zoonotic potential. To understand how SHUV crosses the ruminant placenta, we here infected pregnant ewes and subsequently performed detailed clinical- and histopathological examination of placental tissue. We found that SHUV targets both maternal epithelial cells and fetal trophoblasts, that together form the maternal-fetal interface of the ovine placenta. Experiments with human placental explants, furthermore, revealed replication of SHUV in syncytiotrophoblasts, which are generally highly resistant to virus infections. Our findings provide novel insights into vertical transmission of SHUV in sheep and call for research on the potential risk of SHUV infection during human pregnancies.

Extracellular Vesicle-Related Thrombosis in Viral Infection

Although the outcomes of viral infectious diseases are remarkably varied, most infections cause acute diseases after a short period. Novel coronavirus disease 2019, which recently spread worldwide, is no exception. Extracellular vesicles (EVs) are small circulating membrane-enclosed entities shed from the cell surface in response to cell activation or apoptosis. EVs transport various kinds of bioactive molecules between cells, including functional RNAs, such as viral RNAs and proteins. Therefore, when EVs are at high levels, changes in cell activation, inflammation, angioplasty and transportation suggest that EVs are associated with various diseases. Clinical research on EVs includes studies on the coagulatory system. In particular, abnormal enhancement of the coagulatory system through EVs can cause thrombosis. In this review, we address the functions of EVs, thrombosis, and their involvement in viral infection.

Importance of Viral Disease in Dairy Cow Fertility

Many viral diseases are endemic in cattle populations worldwide. The ability of many viruses to cross the placenta and cause abortions and fetal malformations is well understood. There is also significant evidence that viral infections have additional actions in dairy cows, which are reflected in reduced conception rates. These effects are, however, highly dependent on the time at which an individual animal first contracts the disease and are less easy to quantify. This paper reviews the evidence relating to five viruses that can affect fertility, together with their potential mechanisms of action. Acute infection with non-cytopathic bovine viral diarrhea virus (BVDV) in mid-gestation increases abortion rates or causes the birth of persistently infected calves. BVDV infections closer to the time of breeding can have direct effects on the ovaries and uterine endometrium, which cause estrous cycle irregularities and early embryo mortality. Fertility may also be reduced by BVDV-induced immunosuppression, which increases the susceptibility to bacterial infections. Bovine herpesvirus (BHV)-1 is most common in pre-pubertal heifers, and can slow their growth, delay breeding, and increase the age at first calving. Previously infected animals subsequently show reduced fertility. Although this may be associated with lung damage, ovarian lesions have also been reported. Both BHV-1 and BHV-4 remain latent in the host following initial infection and may be reactivated later by stress, for example associated with calving and early lactation. While BHV-4 infection alone may not reduce fertility, it appears to act as a co-factor with established bacterial pathogens such as Escherichia coli and Trueperella pyogenes to promote the development of endometritis and delay uterine repair mechanisms after calving. Both Schmallenberg virus (SBV) and bluetongue virus (BTV) are transmitted by insect vectors and lead to increased abortion rates and congenital malformations. BTV-8 also impairs the development of hatched blastocysts; furthermore, infection around the time of breeding with either virus appears to reduce conception rates. Although the reductions in conception rates are often difficult to quantify, they are nevertheless sufficient to cause economic losses, which help to justify the benefits of vaccination and eradication schemes.

Modeling the lumpy skin disease risk probability in central Zagros Mountains of Iran

BACKGROUND

New Lumpy Skin Disease (LSD) outbreaks are currently circulating in Chaharmahal and Bakhtiari province, (western Iran, in central Zagros Mountains).

OBJECTIVES

The aim of this study was to model the risk probability of LSD in this area.

METHOD

Data were collected from veterinary organizations between 2012 and 2016. During this period, 290 outbreaks were registered. The herds were grazing and zero grazing. The average size of herds was 2958. We analyzed the potential for an outbreak of LSD in this area basing on the grid maps with the resolution of 1 km. In this study, 22 environmental variables (19 bioclimatic and 3 topography variables) were used to explore the environmental influences on LSD outbreak by maximum entropy ecological niche modeling (MaxEnt).

RESULTS

The results showed that mainly the central, northern, northeast and southern parts of Charmahal and Bakhtiari were the most very high risk areas for LSD. The MaxEnt model performed, with an area under the receiver operating characteristic curve (AUC) of 0.977 and 0.972 for training and test data, respectively. It showed high accuracy for predicting the prevalence of LSD (AUC close to 1). The precipitation of coldest season, isothermality and mean temperature of wettest season made the greatest contribution to the model (68.1%). Evaluating the importance of environmental variables, which were derived from the jackknife test, stated the precipitation of the wettest period and the coldest season and isothermality as the bioclimatic variables in explaining LSD prevalence compared to the other variables.

CONCLUSION

The MaxEnt model could be applied to predict the LSD risk probability of occurrence in central Zagros Mountains of Iran based on the current prevalence data of the disease. Also, the model confirmed that coexistence of weather conditions including defined humidity and temperature is necessary for the disease occurrence.

Mapping changes in the spatiotemporal distribution of lumpy skin disease virus

Lumpy skin disease virus (LSDV) is an infectious disease of cattle transmitted by arthropod vectors which results in substantial economic losses due to impact on production efficiency and profitability, and represents an emerging threat to international trade of livestock products and live animals. Since 2015, the disease has spread into the Northern Hemisphere including Azerbaijan, Kazakhstan, the Russian Federation and the Balkans. The rapid expansion of LSDV in those regions represented the emergence of the virus in more temperate regions than those in which LSDV traditionally occurred. The goal of this study was to assess the risk for further LSDV spread through the (a) analysis of environmental factors conducive for LSDV, and (b) estimate of the underlying LSDV risk, using a combination of ecological niche modelling and fine spatiotemporally explicit Bayesian hierarchical model on LSDV outbreak occurrence data. We used ecological niche modelling to estimate the potential distribution of LSDV outbreaks for 2014-2016. That analysis resulted in a spatial representation of environmental limits where, if introduced, LSDV is expected to efficiently spread. The Bayesian space-time model incorporated both environmental factors and the changing spatiotemporal distribution of the disease to capture the dynamics of disease spread and predict areas in which there is an increased risk for LSDV occurrence. Variables related to the average temperature, precipitation, wind speed, as well as land cover and host densities were important drivers explaining the observed distribution of LSDV in both modelling approaches. Areas of elevated LSDV risks were identified mainly in Russia, Turkey, Serbia and Bulgaria. The results suggest that, if current ecological and epidemiological conditions persist, further spread of LSDV in Eurasia may be expected. The results presented here advance our understanding of the ecological requirements of LSDV in temperate regions and may help in the design and implementation of prevention and surveillance strategies in the region.

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.

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.

Inhibitors of nucleotidyltransferase superfamily enzymes suppress herpes simplex virus replication

Herpesviruses are large double-stranded DNA viruses that cause serious human diseases. Herpesvirus DNA replication depends on multiple processes typically catalyzed by nucleotidyltransferase superfamily (NTS) enzymes. Therefore, we investigated whether inhibitors of NTS enzymes would suppress replication of herpes simplex virus 1 (HSV-1) and HSV-2. Eight of 42 NTS inhibitors suppressed HSV-1 and/or HSV-2 replication by >10-fold at 5 μM, with suppression at 50 μM reaching ∼1 million-fold. Five compounds in two chemical families inhibited HSV replication in Vero and human foreskin fibroblast cells as well as the approved drug acyclovir did. The compounds had 50% effective concentration values as low as 0.22 μM with negligible cytotoxicity in the assays employed. The inhibitors suppressed accumulation of viral genomes and infectious particles and blocked events in the viral replication cycle before and during viral DNA replication. Acyclovir-resistant mutants of HSV-1 and HSV-2 remained highly sensitive to the NTS inhibitors. Five of six NTS inhibitors of the HSVs also blocked replication of another herpesvirus pathogen, human cytomegalovirus. Therefore, NTS enzyme inhibitors are promising candidates for new herpesvirus treatments that may have broad efficacy against members of the herpesvirus family.

Deletion of the NSm virulence gene of Rift Valley fever virus inhibits virus replication in and dissemination from the midgut of Aedes aegypti mosquitoes

BACKGROUND

Previously, we investigated the role of the Rift Valley fever virus (RVFV) virulence genes NSs and NSm in mosquitoes and demonstrated that deletion of NSm significantly reduced the infection, dissemination, and transmission rates of RVFV in Aedes aegypti mosquitoes. The specific aim of this study was to further characterize midgut infection and escape barriers of RVFV in Ae. aegypti infected with reverse genetics-generated wild type RVFV (rRVF-wt) or RVFV lacking the NSm virulence gene (rRVF-ΔNSm) by examining sagittal sections of infected mosquitoes for viral antigen at various time points post-infection.

METHODOLOGY AND PRINCIPAL FINDINGS

Ae. aegypti mosquitoes were fed an infectious blood meal containing either rRVF-wt or rRVF-ΔNSm. On days 0, 1, 2, 3, 4, 6, 8, 10, 12, and 14 post-infection, mosquitoes from each experimental group were fixed in 4% paraformaldehyde, paraffin-embedded, sectioned, and examined for RVFV antigen by immunofluorescence assay. Remaining mosquitoes at day 14 were assayed for infection, dissemination, and transmission. Disseminated infections were observed in mosquitoes as early as three days post infection for both virus strains. However, infection rates for rRVF-ΔNSm were statistically significantly less than for rRVF-wt. Posterior midgut infections in mosquitoes infected with rRVF-wt were extensive, whereas midgut infections of mosquitoes infected with rRVF-ΔNSm were confined to one or a few small foci.

CONCLUSIONS/SIGNIFICANCE

Deletion of NSm resulted in the reduced ability of RVFV to enter, replicate, and disseminate from the midgut epithelial cells. NSm appears to have a functional role in the vector competence of mosquitoes for RVFV at the level of the midgut barrier.

Immunophenotyping of inflammatory cells associated with Schmallenberg virus infection of the central nervous system of ruminants

Schmallenberg virus (SBV) is a recently discovered Bunyavirus associated mainly with abortions, stillbirths and malformations of the skeletal and central nervous system (CNS) in newborn ruminants. In this study, a detailed immunophenotyping of the inflammatory cells of the CNS of affected animals was carried out in order to increase our understanding of SBV pathogenesis. A total of 82 SBV-polymerase chain reaction (PCR) positive neonatal ruminants (46 sheep lambs, 34 calves and 2 goat kids) were investigated for the presence of inflammation in the brain and spinal cord. The study focused on 15 out of 82 animals (18.3%) showing inflammation in the CNS. All 15 neonates displayed lymphohistiocytic meningoencephalomyelitis affecting most frequently the mesencephalon and the parietal and temporal lobes. The majority of infiltrating cells were CD3-positive T cells, followed by CD79α-positive B cells and CD68-positive microglia/macrophages. Malformations like por- and hydranencephaly, frequently found in the temporal lobe, showed associated demyelination and axonal loss. SBV antigen was detected in 37 out of 82 (45.1%) neonatal brains by immunohistochemistry. In particular, SBV antigen was found in 93.3% (14 out of 15 ruminants) and 32.8% (22 out of 67 ruminants) of animals with and without encephalitis, respectively. Highest amounts of virus-protein expression levels were found in the temporal lobe. Our findings suggest that: (i) different brain regions display differential susceptibility to SBV infection; (ii) inflammatory cells in the CNS are found only in a minority of virus infected animals; (iii) malformations occur in association with and without inflammation in the CNS; and (iv) viral antigen is strongly associated with the presence of inflammation in naturally infected animals. Further studies are required to explore the cell tropism and pathogenesis of SBV infection in ruminants.

Lack of evidence for zoonotic transmission of Schmallenberg virus

The risk to public health is absent or extremely low.

The emergence of Schmallenberg virus (SBV), a novel orthobunyavirus, in ruminants in Europe triggered a joint veterinary and public health response to address the possible consequences to human health. Use of a risk profiling algorithm enabled the conclusion that the risk for zoonotic transmission of SBV could not be excluded completely. Self-reported health problems were monitored, and a serologic study was initiated among persons living and/or working on SBV-affected farms. In the study set-up, we addressed the vector and direct transmission routes for putative zoonotic transfer. In total, 69 sheep farms, 4 goat farms, and 50 cattle farms were included. No evidence for SBV-neutralizing antibodies was found in serum of 301 participants. The lack of evidence for zoonotic transmission from either syndromic illness monitoring or serologic testing of presumably highly exposed persons suggests that the public health risk for SBV, given the current situation, is absent or extremely low.