Bovine Viral Diarrhea Research Articles

Seroprevalence of Bovine Viral Diarrhea Virus in Wild Pigs (Sus scrofa) in 17 States in the USA.

Wild pigs (Sus scrofa) are among the most detrimental invasive species in the USA. They are damaging to crops and agriculture, pose a public health risk as reservoirs of zoonotic pathogens, and may also spread disease to livestock. One pathogen identified in wild pigs is bovine viral diarrhea virus (BVDV), a virus that causes an economically important disease of cattle (Bos taurus and Bos indicus). We sought to determine the BVDV seroprevalence in wild pigs in 17 states across the US and to determine whether age category, sex, or location were associated with a positive antibody titer. Serum samples from 945 wild pigs were collected from 17 US states. Virus neutralization assays were performed to determine antibody titers against BVDV-1b and BVDV-2a. Total BVDV seroprevalence for the study area was 5.8% (95% confidence interval [CI], 4.11-8.89). Seroprevalence across all evaluated states was determined to be 4.4% (95% CI, 2.48-6.82) for BVDV-1b and 3.6% (95% CI, 1.54-5.60) for BVDV-2a. The seroprevalence for individual states varied from 0% to 16.7%. There was no statistical difference in median antibody titer for BVDV-1b or BVDV-2a by sex or age category. State seroprevalences for both BVDV-1b and BVDV-2a were associated with wild pig population estimates for those states.

Influence of bovine pestivirus heterogeneity on serological responses to 10 different commercial vaccine formulation

Bovine Pestivirus typically involves one or more organ systems, with clinical manifestations ranging from mild to severe fatal systemic illness that lead to significant reproductive, productive, and economic losses. Vaccines face the challenge of addressing the significant variability of pestiviruses, which affects the interaction between viral antigens and the immune system’s ability to provide protection. This study aimed to evaluate the serological responses against bovine viral diarrhea virus 1 (Pestivirus A) and Pestivirus B induced by 10 commercial vaccines, including one recombinant (vaccine E), two modified live (MLV multivalent, vaccine I, and MLV monovalent, vaccine J), and seven killed vaccines (KLV, vaccines A to H). Additionally, we evaluated the cross-reactivity between Pestivirus A and B from vaccines and HoBi-like pestivirus (Pestivirus H). In Phase 1, guinea pigs were used to screen for non-MLVs. They were divided into nine groups (n=6 each) and received two doses (⅕ of bovine dose) of eight different non-MLV on Days 0 and 21. Serum samples were collected on Days 0 and 30 for serological analyse. In Phase 2, Holstein × Gir heifers (n= 45) were divided into five groups, comprising 6–9 animals. They were vaccinated either once with MLVs or twice with the top non-MLVs screened in Phase 1. Serum samples were harvested on d0 (vaccination day) and d60 (60 days after the first dose) for MLV and non-MLV. Specific antibody titers were assessed virus neutralization (VN) and transformed in log2 for statistical analysis using PROC-MIXED. Significant effects were observed for vaccine groups, time points, and their interactions concerning neutralizing antibodies against Pestivirus A and B in both Guinea pigs and heifers. The Phase 1 study revealed serological responses against Pestivirus A exclusively in non-MLV D (85.33±13.49) and E (72.00±19.26). In the bovine study, the KLD vaccine D (72.00±15.10), recombinant vaccine E (90.66±25.85), and MLV I (170.66±28.22) resulted in an average of neutralizing antibodies against Pestivirus A that exceeded the protective threshold (≥ 60). However,individual analysis of heifers showed a higher frequency of animals presenting titers of Pestivirus A Ab surpassing 32 following vaccination with MLV I and J. None of the vaccine formulations in either study elicited a protective immune response against Pestivirus B or demonstrated cross-reactivity against Pestivirus H.

Genetic analyses of the structural protein E2 bovine viral diarrhea virus isolated from dairy cattle in Yogyakarta, Indonesia.

Bovine viral diarrhea (BVD), a highly pathogenic ribonucleic acid (RNA) virus, causes devastating financial losses and reproductive deaths among dairy cattle in Yogyakarta and globally. This study aimed to identify point mutations within the E2 structural protein of the acquired BVD virus (BVDV) isolates using genetic analysis. The study period shows that we performed the research in 2023. We collected 118 serum samples from 2019 to 2023, among which only 10 BVDV positive were used and 108 were negative lacking the BVDV antigen. An anti-Erns monoclonal antibody-coated protein was used in indirect antigen capture enzyme-linked immunosorbent assay (I-ACE) to detect the BVD antigen present in positive BVDV serum specimens. In the initial step of the two-step reverse transcription polymerase chain reaction, the enzyme (superscript III reverse transcriptase) and the primer (random hexamer) were used to convert the RNA of the BVDV into complementary deoxyribonucleic acid (cDNA) during the process of reverse transcription. The final step involved the amplification of the E2 gene of the resultant BVDV cDNA through gene-specific primers (E2_fwd: 5'-TGGTGGCCTTATGAGAC-3' and P7_rev: 5'-CCCATCATCACTATTTCACC-3') and enzyme (platinum taq DNA polymerase high fidelity). For conducting Sanger sequencing, those 3 BVDV-1-positive isolates (about 2.6% of all isolates) were selected as a typical specimen for each site and year between 2019 and 2023 using a proportional computation. Therefore, only two BVDV isolates with complete genomes were chosen to perform their homological and genetic analysis based on the E2 gene by means of Blast and MEGA Version 11 in addition to the Bioedit 7.2.5 program. By applying phylogenetic analysis relying on the E2 gene, a sum of 1011 nucleotides of the BVDV-1 isolates derived from each of the two BVDV-1 Indonesian isolates (n = 2) and its 23 reference BVDV strains were acquired from the National Center for Biotechnology Information (NCBI) database. The findings of the genetic analysis inside the phylogenetic tree revealed that the two BVDV Indonesian isolates were clustered into BVDV-1a subgenotype, while the reference BVDV strains were clustered into the five BVDV subgenotype, BVDV-1a (n = 6), BVDV-1b (n = 3), BVDV-1c (n = 11), BVDV-1m (n = 1), and BVDV-1n (n = 2). The branch exists in phylogenetic tree located before the division of our two BVDV isolates was divided into two branches with the same maximum bootstrap values of 99%, indicating a high degree of confidence, was seen. Next, we observed the branch near our study samples, which displayed the bootstrap value of 100, indicating that our 02 isolates were identical. In both isolates, V11 BVDV1/Indonesia/Yogyakarta/2023 and V16 BVDV1/Indonesia/Yogyakarta/2023 with GenBank accession numbers PP836388 and PP836389, respectively, conserved D7E residues were mutated as well as cysteine changed/altered into serine (S) was identified at amino acid position 201. We identified two isolates of BVDV belonging to the BVDV-1a subgenotype. Our findings indicate that the conserved D7E residues of isolates V11 BVDV1/Indonesia/Yogyakarta/2023 and V16 BVDV1/Indonesia/Yogyakarta/2023 were altered. The Indonesian BVDV isolates exhibited a cysteine to serine mutation at amino acid position 201, leads to vaccination failure, range of animal's host will increase, and diagnostic kit will not be effective.

Development of a nucleic acid detection method based on the CRISPR-Cas13 for point-of-care testing of bovine viral diarrhea virus-1b.

Bovine viral diarrhea (BVD) is a single-stranded, positive-sense ribonucleic acid (RNA) virus belonging to the genus Pestivirus of the Flaviviridae family. BVD frequently causes economic losses to farmers. Among bovine viral diarrhea virus (BVDV) strains, BVDV-1b is predominant and widespread in Hanwoo calves. Reverse-transcription polymerase chain reaction (RT-PCR) is an essential method for diagnosing BVDV-1b and has become the gold standard for diagnosis in the Republic of Korea. However, this diagnostic method is time-consuming and requires expensive equipment. Therefore, Clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) systems have been used for point-of-care (POC) testing of viruses. Developing a sensitive and specific method for POC testing of BVDV-1b would be advantageous for controlling the spread of infection. Thus, this study aimed to develop a novel nucleic acid detection method using the CRISPR-Cas13 system for POC testing of BVDV-1b. The sequence of the BVD virus was extracted from National Center for Biotechnology Information (NC_001461.1), and the 5' untranslated region, commonly used for detection, was selected. CRISPR RNA (crRNA) was designed using the Cas13 design program and optimized for the expression and purification of the LwCas13a protein. Madin Darby bovine kidney (MDBK) cells were infected with BVDV-1b, incubated, and the viral RNA was extracted. To enable POC viral detection, the compatibility of the CRISPR-Cas13 system was verified with a paper-based strip through collateral cleavage activity. Finally, a colorimetric assay was used to evaluate the detection of BVDV-1b by combining the previously obtained crRNA and Cas13a protein on a paper strip. In conclusion, the CRISPR-Cas13 system is highly sensitive, specific, and capable of nucleic acid detection, making it an optimal system for the early point-of-care testing of BVDV-1b.

Infection status of bovine viral diarrhea virus in Korean native cattle in Jeonbuk State, Korea

Infection status of bovine viral diarrhea virus in Korean native cattle in Jeonbuk State, Korea

Coding-complete genome sequence of a bovine viral diarrhea virus isolate NX2023 from a calf in China.

The coding-complete genome sequence of bovine viral diarrhea virus (BVDV) isolate NX2023 that originated from a calf in China was determined. Phylogenetic analysis showed that the NX2023 strain belongs to the BVDV-1d subgenotype.

Potential role of peste des petits ruminants virus in small ruminant abortions

The aim of the present study was to investigate the frequency, genetic variability, and phylogeny of the peste des petits ruminants virus (PPRV) in ovine and caprine fetuses. During 2014 and 2017, a total of 1054 embryos/fetuses were collected in Turkey. A real-time RT-PCR assay was used for the detection of the PPRV RNA. Genetic characterization and phylogenetic analysis of the PPRV field isolates were conducted by sequencing fusion (F) protein and nucleoprotein (N) gene segments. Samples were also collected from ewes (n = 83) and nanny goats (n = 3) that had aborted and whose embryos/fetuses were found to be PPRV positive. PPRV positive embryos/fetuses were also tested for the presence of Listeria monocytogenes, Campylobacter spp., Coxiella burnetii, Chlamydophila abortus, Brucella spp., akabane virus, aino virus, bluetongue virus, border disease virus, bovine viral diarrhea virus, Cache Valley virus, and Schmallenberg virus. PPRV RNA was detected in 123 (11.7 %) of the 1054 embryos/fetuses, 78 of the 83 (94 %) ewes and 3 (100 %) nanny goats. Border disease virus RNA and Chlamydophila abortus DNA were detected in 7 and 12 PPRV positive sheep fetuses, respectively, while other bacterial and viral agents were not detected. Phylogenetically, the field isolates in this study belong to lineage IV, and compared to other strains of lineage IV considered in this study, they showed 1 and 5 new amino acid substitutions in the F and N gene sequences, respectively. The results of the study suggest that PPRV plays an important role in abortion. Therefore, PPRV needs to be taken into consideration in sheep and goats abortions.

In Vitro Virucidal Activity of Different Essential Oils against Bovine Viral Diarrhea Virus Used as Surrogate of Human Hepatitis C Virus.

The hepatitis C virus (HCV) is a major hepatotropic virus that affects humans with increased risk of developing hepatocellular carcinoma. The bovine viral diarrhea virus (BVDV) causes abortion, calf mortality and poor reproductive performance in cattle. Due the difficulties of in vitro cultivation for HCV, BVDV has been used as surrogate for in vitro assessment of the efficacy of antivirals. Essential oils (EOs) display antiviral and virucidal activity on several viral pathogens. In this study, the virucidal activity of five EOs, Salvia officinalis L. EO (SEO), Melissa officinalis L. EO (MEO), Citrus lemon EO (LEO), Rosmarinus officinalis L. EO (REO) and Thymus vulgaris L. EO (TEO) against BVDV was evaluated in vitro at different concentrations for several time contacts. MEO and LEO were able to considerably inactivate BVDV with a time- and dose-dependent fashion. MEO and LEO at the highest concentrations decreased viral titer by 2.00 and 2.25 log10 TCID50/50 μL at 8 h contact time, respectively. SEO, REO and TEO displayed mild virucidal activity at the highest concentrations for 8 h contact times. In this study, the virucidal efficacies of MEO and LEO against BVDV were observed regardless of compound concentration and contact time. Further studies are needed to confirm the potential use of MEO and LEO as surface disinfectants.

Vaccination protocols in Québec dairy herds

Information is needed on vaccination protocols used by veterinarians and dairy producers to prevent and control infections in dairy herds. This observational study described farm's vaccination standard operating procedures (SOP) developed by veterinarians in collaboration with dairy producers in Québec. Data pertaining to vaccination protocols and dairy producer practices were collected as part of the biosecurity component of the National Mandatory Quality Assurance Certification Program (proAction). Generalized statistical mixed-effects models were used to assess associations between dairy herd characteristics and the vaccination SOP, encompassing various vaccination types. These included any vaccination, core vaccines only (bovine respiratory syncytial virus, infectious bovine rhinotracheitis herpesvirus, parainfluenza virus type 3, bovine viral diarrhea virus type 1 and type 2) and vaccination against diarrhea, mastitis, or clostridial diseases. These models accounted for random variations related to clustering by veterinarians and veterinary clinics. Furthermore, the variance of the outcome was partitioned into producer, veterinarian, and veterinary clinic levels to explore the proportion of the total variance attributable to each group. A total of 3,759 standardized vaccination procedures completed between 2018 and 2021 were analyzed. At least one vaccination target was included in the vaccination SOP in 89% of the dairy herds. The most frequently included vaccine in the SOP was core vaccines, comprising 88%, followed by mastitis (22%), neonatal diarrhea (18%), and clostridial diseases (15%). The vaccination SOPs, particularly core, mastitis, and diarrhea vaccinations, mainly varied due to the veterinarian's characteristics, followed by the clinic's characteristics. In contrast, the decision to included clostridial vaccination primarily varied with the veterinary clinic (76%). Organic producers generally included fewer vaccinations in their SOPs, including core vaccines, than conventional producers. In addition, producers who were providing access to pasture had fewer vaccination SOP for vaccination against mastitis and neonatal diarrhea but more vaccination SOP for clostridial vaccination.

Prevalence and Evolutionary Characteristics of Bovine Coronavirus in China.

Bovine coronavirus (BCoV), bovine rotavirus, bovine viral diarrhea virus, and bovine astrovirus are the most common intestinal pathogenic viruses causing diarrhea in cattle. We collected 1646 bovine fecal samples from January 2020 to August 2023. BCoV was the major pathogen detected, with a positive rate of 34.02% (560/1646). Of the 670 diarrheal samples and 976 asymptomatic samples, 209 and 351 were BCoV-positive, respectively. Studying the relevance of diarrhea associated with BCoV has shown that the onset of diarrheal symptoms post-infection is strongly correlated with the cattle's age and may also be related to the breed. We amplified and sequenced the hemagglutinin esterase (HE), spike protein, and whole genomes of the partially positive samples and obtained six complete HE sequences, seven complete spike sequences, and six whole genomes. Molecular characterization revealed that six strains were branched Chinese strains, Japanese strains, and partial American strains from the GⅡb subgroup. Strains HBSJZ2202 and JSYZ2209 had four amino acid insertions on HE. We also analyzed ORF1a and found disparities across various regions within GIIb, which were positioned on separate branches within the phylogenetic tree. This work provides data for further investigating the epidemiology of BCoV and for understanding and analyzing BCoV distribution and dynamics.

Leptospirosis as a cause of infertility in Uruguayan beef cattle

Leptospirosis, caused by pathogenic spirochetes of the genus Leptospira spp., is a globally significant zoonotic disease that affects humans and animals. In cattle, leptospirosis is associated not only with overt clinical manifestations but also with reproductive diseases, including infertility. This study assesses the potential correlation between leptospirosis and infertility in Uruguayan beef cattle. A case-control study involved 31 beef herds with no prior history of Leptospira vaccination. In each herd, veterinarians identified 10 non-pregnant (cases) and 25 pregnant cows (controls) using ultrasound, and blood and urine samples were collected from each cow. Serological diagnosis was performed using the Microscopic Agglutination Test (MAT), and quantitative PCR (qPCR) was used to assess Leptospira excretion. Additionally, antibodies against bovine viral diarrhea virus (BVDV) and infectious bovine rhinotracheitis (IBR) were tested. The results demonstrated an association between seropositivity to the Sejroe serogroup (cut-off 1:200) and infertility in cattle (OR=1.31; p-value=0.06). Furthermore, the level of Leptospira excretion (qPCR) in urine was associated with increased infertility risk, with cows excreting over 100 copies per mL of urine having the highest odds of infertility (OR=2.34; p-value<0.01). This study suggests a potential association between leptospirosis and infertility in Uruguayan beef cattle, emphasizing the importance of both serological and molecular diagnostics for assessing reproductive health in cattle herds. Future research should explore the impact of Leptospira serogroups on other reproductive disorders in cattle.

Utilizing Rapid Hydrogen Peroxide Generation from 6-Hydroxycatechol to Design Moisture-Activated, Self-Disinfecting Coating.

A coating that can be activated by moisture found in respiratory droplets could be a convenient and effective way to control the spread of airborne pathogens and reduce fomite transmission. Here, the ability of a novel 6-hydroxycatechol-containing polymer to function as a self-disinfecting coating on the surface of polypropylene (PP) fabric was explored. Catechol is the main adhesive molecule found in mussel adhesive proteins. Molecular oxygen found in an aqueous solution can oxidize catechol and generate a known disinfectant, hydrogen peroxide (H2O2), as a byproduct. However, given the limited amount of moisture found in respiratory droplets, there is a need to enhance the rate of catechol autoxidation to generate antipathogenic levels of H2O2. 6-Hydroxycatechol contains an electron donating hydroxyl group on the 6-position of the benzene ring, which makes catechol more susceptible to autoxidation. 6-Hydroxycatechol-coated PP generated over 3000 μM of H2O2 within 1 h when hydrated with a small amount of aqueous solution (100 μL of PBS). The generated H2O2 was three orders of magnitude higher when compared to the amount generated by unmodified catechol. 6-Hydroxycatechol-containing coating demonstrated a more effective antimicrobial effect against both Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria when compared to unmodified catechol. Similarly, the self-disinfecting coating reduced the infectivity of both bovine viral diarrhea virus and human coronavirus 229E by as much as a 2.5 log reduction value (a 99.7% reduction in viral load). Coatings containing unmodified catechol did not generate sufficient H2O2 to demonstrate significant virucidal effects. 6-Hydroxycatechol-containing coating can potentially function as a self-disinfecting coating that can be activated by the moisture present in respiratory droplets to generate H2O2 for disinfecting a broad range of pathogens.

Exosomes-mediated transmission of standard bovine viral diarrhea strain OregonC24Va in bovine trophoblast cells

Bovine viral diarrhoea virus (BVDV) can infect cows on days 30–110 of gestation and crossing the placental barrier, resulting in persistently infected (PI) and causing significant economic losses to dairy farming. Bovine placental trophoblast cells (BTCs) are the major cells in the early chorionic tissue of the placenta and play important roles in placental resistance to viral transmission. In this study, we have confirmed that BTCs is among a groups of cell types those could be infected by BVDV in vivo, and BVDV infection stimulates the autophagic responses in BTCs and promotes the release of exosomes. Meanwhile, the exosomes derived from BTCs can be used by BVDV to spread between placental trophoblast cells, and this mode of transmission cannot be blocked by antibodies against the BVDV E2 protein, whereas the replication and spread of BVDV in BTCs can be blocked by inhibiting autophagy and exosomogenesis. Our study provides a theoretical and practical basis for scientific prediction and intervention of reproductive disorders caused by BVDV infection in cows of different gestation periods from a novel perspective.

Effective utilization of vaccination to protect against viral reproductive pathogens

Bovine viral diarrhea virus (BVDV) and Bovine alphaherpes­virus-1 (BoHV-1) have long been recognized as major causes of reproductive disease in beef and dairy cattle. Enhancing im­munity through prebreeding vaccination and annual revaccina­tion of the cowherd provide important contributions to limiting reproductive losses associated with these viral infections and are also important control procedures to limit transmission of these viruses among cattle populations. While providing efficacy, vaccination should also be safe. Safety concerns are often associated with the BoHV-1 fractions, while efficacy con­cerns are often associated with BVDV fractions of multivalent vaccines. Vaccination against BVDV and BoHV-1 effectively decrease risk of fetal infection, including abortions, birth of per­sistently infected BVDV carriers, and pregnancy loss. Safety con­cerns associated with viral vaccines, more specifically modified-live viral vaccines, should not overshadow the protective effects associated with sound vaccination principles and programs.

Leukocyte dynamics in vaccinated and unvaccinated animals following dual challenge with Bovine Viral Diarrhea Virus-Mannheimia haemolytica model to compare vaccine efficacy in calves

Bovine respiratory disease continues to be the greatest threat to calf health. One of the common recommendations is to vaccinate young beef and dairy calves at 30-60 days of age to provide protection at weaning or when commingled. The study objective was to determine whether there were any dif­ferential leukocyte changes that could be measured following a dual challenge with Bovine Viral Diarrhea Virus (BVDV) and M. haemolytica ~5 months after vaccination.

Pigs in southern Italy are exposed to three ruminant pathogens: an analysis of seroprevalence and risk factors analysis study

BackgroundPigs are susceptible to several ruminant pathogens, including Coxiella burnetti, Schmallenberg virus (SBV) and bovine viral diarrhea virus (BVDV). These pathogens have already been described in the pig population, although the dynamics of the infection and the impact on pig farms are currently unclear. The aim of this work was to evaluate the presence of these infections in the pig population of the Campania region, southern Italy, and to evaluate the risk factors associated with a greater risk of exposure.ResultsA total of 414 serum samples belonging to 32 herds were tested for the presence of antibodies against SBV, Coxiella, and BVD using commercial multispecies ELISA kits. SBV (5.3%) was the most prevalent pathogen, followed by Coxiella (4.1%) and BVD (3%). The risk factors included in the study (age, sex, province, farming system, ruminant density and major ruminant species) had no influence on the probability of being exposed to BVD and Coxiella, except for the location, in fact more pigs seropositive to Coxiella were found in the province of Caserta. However, the univariate analysis highlighted the influence of age, location, and sex on exposure to SBV. The subsequent multivariate analysis statistically confirmed the importance of these factors. The presence of neutralizing antibodies for SBV and BVDV, or antibodies directed towards a specific phase of infection for Coxiella was further confirmed with virus-neutralization assays and phase-specific ELISAs in a large proportion of positive samples. The presence of high neutralizing antibody titers (especially for SBV) could indicate recent exposures. Twelve of the 17 positive samples tested positive for antibodies against Coxiella phase I or II antigens, indicating the presence of both acute and chronic infections (one animal tested positive for both phases antibodies).ConclusionsOur study indicates a non-negligible exposure of pigs from southern Italy to the above pathogens. Further studies are necessary to fully understand the dynamics of these infections in pigs, the impact on productivity, and the public health consequences in the case of Coxiella.

Simultaneous detection of bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BoHV-1) using recombinase polymerase amplification

Bovine viral diarrhea virus (BVDV) is considered to be the most common agent of severe diarrhea in cattle worldwide, causing fever, diarrhea, ulcers, and abortion. Bovine herpesvirus 1 (BoHV-1) is also a major bovine respiratory disease agent that spreads worldwide and causes extensive damage to the livestock industry. Recombinase polymerase amplification (RPA) is a novel nucleic acid amplification method with the advantages of high efficiency, rapidity and sensitivity, which has been widely used in the diagnosis of infectious diseases. A dual RPA assay was developed for the simultaneous detection of BVDV and BoHV-1. The assay was completed at a constant temperature of 37 °C for 30 min. It was highly sensitive and had no cross-reactivity with other common bovine viruses. The detection rate of BVDV RPA in clinical samples (36.67%) was higher than that of PCR (33.33%), the detection rate of BoHV-1 RPA and PCR were equal. Therefore, the established dual RPA assay for BVDV and BoHV-1 could be a potential candidate for use as an immediate diagnostic.

The first evidence of bovine viral diarrhea virus circulation in Libya.

Bovine viral diarrhea (BVD) is endemic in North Africa and the Mediterranean Basin with high socioeconomic impacts. However, there are no data on this disease in Libya. One of the aims of this study was to provide data on BVD in Libya, to fill in the gap in the region and to investigate the level of seroprevalence of BVD virus (BVDV) in Libya and associated risk factors. A total of 1599 serum samples were collected from cattle herds belonging to seven Libyan regions. All sera were assayed using a screening enzyme-linked immunosorbent assay for the detection of antibodies against BVDV. The overall seroprevalence of BVDV was estimated to be 48.6% (95% confidence interval, 46.08%-50.98%). A seroprevalence rate of 36.8% was detected in cattle aged <1 year, 41.0% in cattle aged between 1 and 2 years, and 49.7% in cattle aged >2 years. Statistically significant differences (p = 0.001) were observed between age groups. BVDV seroprevalence was significantly associated with geographical region (p = 0.033). To the best of our knowledge, this is the first study on BVD in Libya, and the results suggest that BVD is endemic in Libya. Further studies are required to isolate and characterize the circulated BVDV in Libya.

Epigenetic Modifications of White Blood Cell DNA Caused by Transient Fetal Infection with Bovine Viral Diarrhea Virus.

Bovine viral diarrhea virus (BVDV) infections cause USD 1.5-2 billion in losses annually. Maternal BVDV after 150 days of gestation causes transient fetal infection (TI) in which the fetal immune response clears the virus. The impact of fetal TI BVDV infections on postnatal growth and white blood cell (WBC) methylome as an index of epigenetic modifications was examined by inoculating pregnant heifers with noncytopathic type 2 BVDV or media (sham-inoculated controls) on Day 175 of gestation to generate TI (n = 11) and control heifer calves (n = 12). Fetal infection in TI calves was confirmed by virus-neutralizing antibody titers at birth and control calves were seronegative. Both control and TI calves were negative for BVDV RNA in WBCs by RT-PCR. The mean weight of the TI calves was less than that of the controls (p < 0.05). DNA methyl seq analysis of WBC DNA demonstrated 2349 differentially methylated cytosines (p ≤ 0.05) including 1277 hypomethylated cytosines, 1072 hypermethylated cytosines, 84 differentially methylated regions based on CpGs in promoters, and 89 DMRs in islands of TI WBC DNA compared to controls. Fetal BVDV infection during late gestation resulted in epigenomic modifications predicted to affect fetal development and immune pathways, suggesting potential consequences for postnatal growth and health of TI cattle.

Genotypic analysis of a localised hotspot of Pestivirus A (BVDV-1) infections in Northern Ireland.

Bovine viral diarrhoea (BVD) is caused by Pestivirus A and Pestivirus B. Northern Ireland (NI) embarkedon a compulsory BVD eradication scheme in 2016, which continues to this day, so an understanding of the composition of the pestivirus genotypes in the cattle population of NI is required. This molecular epidemiology study employed 5' untranslated region (5'UTR) genetic sequencing to examine the pestivirus genotypes circulating in samples taken from a hotspot of BVD outbreaks in the Enniskillen area in 2019. Bovine viral diarrhoea virus (BVDV)-1e (Pestivirus A) was detected for the first time in Northern Ireland, and at a highfrequency, in an infection hotspot in Enniskillen in 2019. There was no evidence of infection with BVDV-2 (Pestivirus B), Border disease virus (pestivirus D) or HoBi-like virus/BVDV-3 (pestivirus H). Only 5'UTR sequencing was used, so supplementary sequencing, along with phylogenetic trees that include all BVDV-1 genotype reference strains, would improve accuracy. Examination of farm locations and animal movement/trade is also required. Genotype BVDV-1e was found for the first time in Northern Ireland, indicating an increase in the genetic diversity of BVDV-1, which could have implications for vaccine design and highlights the need for continued pestivirus genotypic surveillance.