Bovine Viral Diarrhea Virus Antigen Research Articles

Severe disease in neonatal calves with detection of cytopathic BVDV

ALL bovine viral diarrhoea virus (BVDV) strains can appear both as the cytopathic and the non-cytopathic biotype. Although both can infect the fetus, only non-cytopathic BVDV is able to cause...

Fetal protection in heifers vaccinated with a modified-live virus vaccine containing bovine viral diarrhea virus subtypes 1a and 2a and exposed during gestation to cattle persistently infected with bovine viral diarrhea virus subtype 1b

To determine efficacy of a modified-live virus (MLV) vaccine containing bovine viral diarrhea virus (BVDV) 1a and 2a against fetal infection in heifers exposed to cattle persistently infected (PI) with BVDV subtype 1 b. 50 heifers and their fetuses. Susceptible heifers received a placebo vaccine administered IM or a vaccine containing MLV strains of BVDV1a and BVDV2a administered IM or SC. On day 124 (64 to 89 days of gestation), 50 pregnant heifers (20 vaccinated SC, 20 vaccinated IM, and 10 control heifers) were challenge exposed to 8 PI cattle. On days 207 to 209, fetuses were recovered from heifers and used for testing. 2 control heifers aborted following challenge exposure; both fetuses were unavailable for testing. Eleven fetuses (8 control heifers and 1 IM and 2 SC vaccinates) were positive for BVDV via virus isolation (VI) and for BVDV antigen via immunohistochemical analysis in multiple tissues. Two additional fetuses from IM vaccinates were considered exposed to BVDV (one was seropositive for BVDV and the second was positive via VI in fetal tissues). A third fetus in the SC vaccinates was positive for BVDV via VI from serum alone. Vaccination against BVDV provided fetal protection in IM vaccinated (17/20) and SC vaccinated (17/20) heifers, but all control heifers (10/10) were considered infected. 1 dose of a BVDV1a and 2a MLV vaccine administered SC or IM prior to breeding helped protect against fetal infection in pregnant heifers exposed to cattle PI with BVDV1b.

Natural <i>in utero</i> infection of neonatal calves with bovine viral diarrhoea virus on a large dairy farm in Saudi Arabia

The dairy industry is a large and important business in Saudi Arabia. Although farms are administered to high international standards, some reproduction problems, of uncertain aetiology, are encountered. The most frequently seen are conception failures, abortions, stillbirths and the birth of weak or malformed calves. These conditions are suggestive of bovine viral diarrhoea virus (BVDV) infection. Unfortunately, very little published information is available regarding the impact of this disease on cattle populations in Saudi Arabia. As a consequence, the present study was carried out and is the first of its kind in Saudi Arabia and the Gulf region. The aim of the study was to elucidate the role of in utero BVDV infection leading to the birth of weak or malformed calves on a large dairy farm in Saudi Arabia. The study was divided into two parts. Firstly, apparently healthy neonatal calves were sampled for the detection of pre-colostral serum antibodies to BVDV. The presence of these antibodies indicates exposure of the foetus to BVDV during the last two trimesters of gestation. Secondly, tissue samples from malformed neonatal calves were examined for the presence of BVDV antigens. Detection of such antigens confirms exposure of the foetus to the virus during the first trimester of gestation. The results of the investigation indicated that 36.1% of the neonatal calves were exposed to BVDV infection in utero. This is higher than what has been reported in the literature and suggests that dairy farmers in the Arabian Peninsula need to be made aware of the dangers of BVDV infections in their herds. The epidemiological significance of the results is discussed.

Development and evaluation of a Luminex multiplex serology assay to detect antibodies to bovine herpes virus 1, parainfluenza 3 virus, bovine viral diarrhoea virus, and bovine respiratory syncytial virus, with comparison to existing ELISA detection methods

Detection of circulating antibodies to bovine herpes virus 1 (BHV-1), parainfluenza 3 virus (PI3V), bovine viral diarrhoea virus (BVDV) and bovine respiratory syncytial virus (BRSV) using ELISA is widely used for veterinary diagnostics and surveillance. In this paper, the potential of a multiplex serology test based on Luminex technology, where all antibodies are simultaneously detected in a single assay was investigated. The performance of “in-house” separate ELISAs which use relatively crude lysates of cultured virus as capture antigens, was compared to the multiplex assay where the same antigens were covalently bound to the fluorescent beads used in the Luminex platform. A panel of field serum samples was tested by the multiplex assay in parallel with the separate routine ELISAs to provide a comparison between tests. The BHV-1 and PI3V components of the multiplex test showed similar sensitivities and specificities to the separate “in-house” ELISAs. The performance of the BVDV and BRSV components was less successful and was attributed to relatively low signal strength for these antigens, leading to higher assay variability and a reduced ability to distinguish positive and negative samples compared to the “in-house” ELISAs. The results illustrated that antigens commonly used successfully in ELISAs cannot always be transferred for use in alternative assay systems. The use of recombinant BVDV E2 protein was investigated and was shown to lead to an appreciable increase in signal strength compared to the use of crude BVDV antigen in the Luminex system.

Bovine Viral Diarrhea Virus (BVDV) Infection in Relation to Fertility in Heifers

In this study, blood serum and leukocyte samples were collected from 400 Holstein heifers, all of which appeared to be healthy. Antibodies (Ab) against bovine viral diarrhea virus (BVDV) were detected in 57 serum samples, and BVDV antigen (Ag) was detected in 38 leukocyte samples. There were statistically important differences between the average first insemination ages (FIT) of the BVDV (Ag-/Ab+) heifers (p<0.0001) (pregnant p<0.05, nonpregnant p<0.0001) and BVDV (Ag-/Ab-) heifers. The average conception rates (CR) of BVDV (Ag-/Ab+) heifers and BVDV (Ag-/Ab-) heifers were not significant statistically. There were statistically important differences in average FIT between persistent infected (PI) BVDV (Ag+/Ab-) heifers (p<0.0001; PI pregnant p<0.05, PI nonpregnant p<0.0001) and BVDV (Ag-/Ab-) heifers. No significant differences in average CR between PI BVDV (Ag+/Ab-) heifers and BVDV (Ag-/Ab-) heifers were found. The differences in average FIT between BVDV (Ag+/Ab+; p<0.0001; nonpregnant p<0.0001) and BVDV (Ag-/Ab-) heifers were important statistically. Although there were no BVDV (Ag+/Ab+) pregnant heifers, the differences in average CR between BVDV (Ag+/Ab+) pregnant heifers and BVDV (Ag-/Ab-) heifers were found to be statistically important (p<0.0001). We conclude that fertility is affected in heifers with BVDV (Ag-/Ab+, Ag+/Ab- and Ag+/Ab+).

Indications of a relationship between buying-in policy and infectious diseases on dairy farms in Wales

During the period February to May 2008, bulk milk samples were collected from 57 dairy farms throughout Wales in the framework of a voluntary somatic cell count project. Bulk milk...

Characterization and Phylogenetic Analysis of Bovine Viral Diarrhea Virus in Brain Tissues from Nonambulatory (Downer) Cattle in Korea

Between August 2008 and May 2009, 386 brain and serum samples from adult cattle (2-7 years old) showing a variety of clinical signs of downer cow syndrome were received by the National Veterinary Research and Quarantine Service. All brain samples were tested for the presence of Bovine viral diarrhea virus (BVDV) by reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and antigen capture ELISA (Ag-ELISA). The BVDV nucleic acid was detected in 54 of 386 (15.5%) brain samples tested by RT-PCR. Positive results were detected in 14 (3.67%) and 13 (3.4%) of samples tested by IHC and Ag-ELISA, respectively. Both BVDV nucleic acid and antigen were detected in 11 cattle (2.9%) by all 3 diagnostic tests; however, antibodies against BVDV were not detected in these 11 cattle. A molecular classification of the identified viral strains (n = 40) was also carried out. Neighbor-joining phylogenetic analysis revealed that most of the identified viruses belonged to BVDV genotype 1a (n = 10), 1b (n = 16), and 2a (n = 8). The remaining strains were subtypes 1c (n = 1), 1n (n = 4), and 1m (n = 1). Interestingly, most of the BVDV-1b strains (n = 9) identified in brain samples were confirmed by all 3 diagnostic tests. Further studies should be performed to determine why the BVDV-1b strain was found in brain samples that were positive using all 3 diagnostic tests.

The first report on the prevalence of pestivirus infection in camels in Sudan

The role of pestivirus particularly bovine viral diarrhea virus (BVDV) in causing respiratory infections in camels was studied in four different localities in Sudan. The evaluation was carried out using ELISA, and positive specimens were further tested using direct fluorescent antibody technique (FAT) and reverse transcriptase polymerase chain reaction (RT-PCR) for confirmation. The overall detected seroprevalence of BVD in camel sera was 84.6% with the highest prevalence in Western Sudan (92.5%) and with most of positives showing 2+ and 3+ titer. Out of 186 lung specimens examined for BVDV antigen, 13 were found positive (7%) with the highest prevalence in Central Sudan. All ELISA-positive specimens were positive using FAT and RT-PCR. To our knowledge, this is the first report for the detection of BVDV antigen and antibodies in camels in Sudan.

Prevalência da infecção pelo Vírus da Diarréia Viral Bovina (BVDV) no Estado de Goiás, Brasil

This study was performed to estimate the seroprevalence of bovine viral diarrhea virus (BVDV) in a population of non-vaccinated cattle in Goias State, Brazil, and to determine the potential risk factors related to the seropositivity. Serum samples were collected from 3,533 animals of 888 herds from 232 municipalities in Goias between March and September, 2002. These samples were submitted to the serum neutralization test and an epidemiological questionnaire was filled out for each herd to investigate variables that could be associated with this infection. The data were analyzed using Epi Info 6.04. In addition, 960 BVDV antibody-negative sera were further tested by antigen-ELISA in order to identify persistently infected animals (PI). The seroprevalence was 64.0% and 784 (88.3%) herds had at least one seropositive animal. Two hundred and twenty six (97.4%) municipalities showed at least one positive herd/animal. Only age influenced the presence of neutralizing antibodies to this virus in animals. None of the exposure variables analyzed was considered as a risk factor for the infection with BVDV in cattle herds. Four (0.4%) of 960 seronegative samples were BVDV antigen positive. Based on these results, we concluded that BVDV infection is spread among cattle herds in Goias State, Brazil.

Effect of the viral protein Npro on virulence of bovine viral diarrhea virus and induction of interferon type I in calves

To characterize the influence of the viral protein N(pro) on virulence of bovine viral diarrhea virus (BVDV) and on type I interferon responses in calves. 10 calves, 4 to 6 months of age. BVDV virulence and type I interferon responses of calves (n = 5) infected with a noncytopathic BVDV with a deleted N(pro) were compared with those of calves (5) infected with a noncytopathic BVDV with a functional N(pro). Rectal temperatures, clinical signs, platelet counts, and total and differential WBC counts were evaluted daily. Histologic examinations and immunohistochemical analyses of tissues were conducted to assess lesions and distribution of viral antigens, respectively. Serum type I interferon concentrations were determined. Calves infected with N(pro)-deleted BVDV developed leukopenia and lymphopenia, without developing increased rectal temperatures or lymphoid depletion of target lymphoid organs. There was minimal antigen deposition in lymphoid organs. Calves infected with N(pro) BVDV developed increased rectal temperatures, leukopenia, lymphopenia, and lymphoid depletion with marked BVDV antigen deposition in lymphatic tissues. Interferon type I responses were detected in both groups of calves. Deletion of N(pro) resulted in attenuation of BVDV as evidenced by reduced virulence in calves, compared with BVDV with a functional N(pro). Deletion of N(pro) did not affect induction of type I interferon. The N(pro)-deleted BVDV mutant may represent a safe noncytopathic virus candidate for vaccine development.

Development and validation of an ELISA for quantitation of Bovine Viral Diarrhea Virus antigen in the critical stages of vaccine production

Bovine Viral Diarrhea Virus (BVDV) is the causative agent of a worldwide disease. The virus infects bovines of all ages, causing reproductive problems and contaminating biological products of high commercial value. The large-scale production of BVDV vaccines presents the challenge of processing antigenic proteins that are highly susceptible to the processing environment. Potency testing requires the immunization of cattle in order to determine the neutralizing antibodies titers induced by the vaccine. An alternative to the in vivo test is an in vitro measurement of key viral antigens. This paper describes the development and validation of a sandwich-type indirect ELISA that is able to detect and quantify BVDV E2 glycoprotein in live and inactivated BVDV. Validation parameters such as repeatability, intermediate precision, and reproducibility indicated that the developed ELISA constitutes an advanced tool for evaluating the BVDV antigen throughout manufacturing and vaccine release testing.

Morphological Changes and Virus Distribution in the Ileum of Colostrum-Deprived Calves Inoculated with Non-Cytopathic Bovine Viral Diarrhoea Virus Genotype-1

Eight colostrum-deprived calves were inoculated intranasally with a non-cytopathic strain of bovine viral diarrhoea virus (BVDV) genotype-1 and killed in batches of two at 3, 6, 9 and 14 days post-inoculation (dpi). Two non-inoculated animals with similar background served as controls. All infected calves developed mild pyrexia and transient leucopenia due primarily to lymphopenia. Viraemia was correlated with body temperature and inversely related to leucocyte count. Ileal Peyer's patches developed mild follicular lymphoid depletion from 3dpi. This change was accompanied by cellular fragmentation and pyknosis, characteristic of apoptosis, which was most prominent from 6dpi. Lymphocyte apoptosis was confirmed by ultrastructural examination. Stellate cells and macrophages located in the lymphoid follicles were identified as infected by virus from 3dpi and the number of these infected cells increased until 9dpi. Fewer lymphocytes expressed BVDV antigen. Macrophages had morphological features consistent with activation of secretory and phagocytic function from 3dpi. These findings suggest that BVDV is only directly responsible for the destruction of a small number of lymphocytes. Although lymphocyte infection coincided with the onset of apoptosis, the intensity of infection was disproportionate to the marked depletion of gut-associated lymphoid tissue, particularly during the early stages of this process. Characterization of the indirect pathogenic mechanisms involved in the lymphoid depletion associated with BVDV infection will require additional study.

Pestivirus infections in cervids from the Czech Republic

372 sera of cervids from the Czech Republic were examined for antibodies to the bovine viral diarrhea virus (BVDV) and border disease virus (BDV) by competitive-inhibition enzyme-linked immunosorbent assay (ELISA), and for the presence of the BVDV by AgELISA. Antibodies to BVDV/BDV were found in 0.6% (two positive/305 tested) red deer (&lt;I&gt;Cervus elaphus&lt;/I&gt;). BVDV/BDV antibodies were not found in four sika deer (&lt;I&gt;Cervus Nippon&lt;/I&gt;) and 63 fallow deer (&lt;I&gt;Dama dama&lt;/I&gt;). All serum samples were BVDV antigen negative. Our results confirmed that red deer in the Czech Republic are only rarely infected with Pestiviruses. This was the first survey of pestiviruses in farmed and wild cervids in the Czech Republic.

Development of a sandwich Dot-ELISA for detecting bovine viral diarrhea virus antigen with E2 recombinant protein

The IgG antibodies of rabbit anti-E2 protein of the bovine viral diarrhea virus were prepared by a general method from high efficiency serum immunized by E2 recombinant protein antigen expressed in E. coli prokaryotic expression system and were labeled to make enzyme-labeled antibody with the method of NaIO4. A sandwich Dot enzyme-linked immunosorbent assay (Dot-ELISA) for the detection of BVDV was developed. The optimal reaction conditions of Dot-ELISA were determined. The results show that optimal coating antibody was 300 μg·mL−1, the working concentration of HRP-labeled antibody was 1:50. The optimal blocking reagent and time were 5% bovine serum and 45 min. The minimum detection of the content of antigen reached 1.35 μg·mL−1. Compared with the routine IDEXX ELISA test kit with the whole virus, its specificity, sensitivity and coincidence rate were 90.48%, 96.55% and 95.24%, respectively. Compared with the sandwich Dot-ELISA with the negative staining electron microscope and RT-PCR, the coincidence rates were 90.9% and 93.1%, respectively. In addition, Bovine viral diarrhea virus (BVDV) antigen of 178 samples collected from cow farms in the Hebei Province, China, were detected by the developed Dot-ELISA and the IDEXX BVDV antigen Test Kit simultaneously, BVDV antigen positive rate was 39.89%–41.01%. The result of detecting clinical samples demonstrated that the established method showed its specificity, sensitivity and repeatability, whereas the results were easily interpreted without an ELISA reader.

Distribution of Bovine Viral Diarrhea Virus Antigen in Aborted Fetal and Neonatal Goats by Immunohistochemistry

Bovine viral diarrhea virus (BVDV) infection in goats can result in severe reproductive losses, with abortion rates reaching 80%. Infection with BVDV in aborted goat fetuses and stillborn kids can result in placentitis, encephalitis, myocarditis, and thymic depletion. This study investigates the distribution of viral antigen within the organ systems of aborted goat fetuses, stillborn kids, and nonviable kids infected with BVDV at various stages of gestation using immunohistochemistry (IHC). Virus antigen was detected within the placenta (8/13), thymus (4/9), heart (4/11), and brain (4/15) of affected goats. Uncommonly, BVDV antigen was detected within the skin (1/14), liver (1/13), kidney (1/12), lung (1/11), and trachea (1/3). BVDV antigen was not detected within the spleen (0/9), nasal turbinate (0/2), or thyroid (0/3). The results of this study indicate that placenta, heart, thymus, and brain are the most reliable tissues for BVDV antigen detection using IHC in aborted goat fetuses.

Testing of Cattle Ear Notch Samples Using a Bovine Viral Diarrhea Virus NS3 Antigen ELISA Kit for Detection of Persistently Infected Animals

Identification and elimination of persistently infected (PI) cattle is important to controlling bovine viral diarrhea virus (BVDV) in herds. Compared to many diagnostic laboratory techniques, ELISA (enzyme linked immunosorbent assay) is convenient due to the ability to test large number of samples rapidly and consistently. A virus can be detected by probing for a specific nonstructural antigen like the NS3 (p80 in former nomenclature) or a structural antigen like the glycoprotein Erns (E0 or gp48 in former nomenclatures). Ear notch samples can be obtained easily and quickly from cattle. Another important advantage of ear notch skin biopsy samples is that they contain a high concentration of BVDV antigen. Few publications can be found describing the detection of NS3 in ear notches from cattle. The objective of this study was to compare the performance of a current commercial ELISA which specifically detects the NS3 antigen on ear notches from cattle to other tests utilized in diagnostic laboratories.

Persistent Bovine Viral Diarrhea virus Infection in Wild Cervids of Colorado

Bovine viral diarrhea virus (BVDV) is a significant viral pathogen of domestic cattle. Worldwide, there is evidence of BVDV exposure and infection in wild ungulates; however, the frequency and significance of such events are unknown. To determine the prevalence and distribution of Colorado deer, elk, and moose persistently infected (PI) with BVDV, a cross-sectional study was conducted using full-thickness ear tissue samples collected from animals presented to the Colorado Division of Wildlife for chronic wasting disease surveillance in the 2005-2006 hunting season. Tissue from 5,597 harvested animals (2,934 mule deer, 2,516 elk, 141 white-tailed deer, and 6 moose) was paraffin-embedded and stained for BVDV using immunohistochemistry. A single adult male mule deer had BVDV antigen in the skin; staining distribution was consistent with that seen in PI cattle. Skin and lymph node were also positive for viral RNA by polymerase chain reaction, and the virus was determined to be a type 1. The prevalence of BVDV PI cervids in Colorado is very low. However, the identification of a naturally infected adult PI animal in the wild suggests that the virus infects free-ranging populations. The source of the BVDV is unknown and is assumed to be spillover from cattle or maintenance within wildlife populations. Consideration of a potential wild animal reservoir is important in the design and implementation of BVDV management practices in cattle.

Systemic Reactive Angioendotheliomatosis-like Syndrome in a Steer Presumed to be Persistently Infected with Bovine Viral Diarrhea Virus

Unusual proliferative intravascular lesions were seen in multiple organs of a 2-year-old Corriente steer presumed to be persistently infected with bovine viral diarrhea virus (BVDV), based on widespread immunohistochemical detection of BVDV antigen. Proliferations of spindle cells, which were immunohistochemically positive for von Willebrand factor-related antigen, partially-to-completely occluded vessel lumens and were supported by cells that were immunohistochemically positive for smooth muscle actin. Distribution and character of the intraluminal proliferations are strikingly similar to those described in feline systemic reactive angioendotheliomatosis, a rare entity of unknown cause. The presence of occasional intravascular thrombi suggests that the proliferative vasculopathy was associated with an underlying thrombotic process with immunohistochemical similarities to thrombotic thrombocytopenic purpura of humans. Death of the steer was due to hemorrhage from a castration wound, which may indicate thrombocytopenia or platelet dysfunction. The role of persistent BVDV infection in the formation of the intravascular lesions is unknown.

Outbreak of Salmonella enterica serotype Newport in a beef cow-calf herd associated with exposure to bovine viral diarrhea virus

Severe disease and death in cows and calves affected 1 of 3 separate groups (A, B, and C) of cattle on a commercial cow-calf operation. Clinical illness consisting of severe watery and bloody diarrhea, dehydration, weakness, and death affected adult cows and calves in 1 group (group B). Salmonella enterica serotype Newport was recovered from tissues of cows and calves from group B. Despite supportive and antimicrobial treatment of cattle in group B, cow mortality rate attributable to salmonellosis in that group was 7.9% (32/407); calf mortality rate was 14.4% (52/361). None of the cows in Groups A or C died, and the calf mortality rate in those groups was low. Salmonella enterica serotype Newport was recovered from pooled fecal samples subsequently collected from each group of cows. Bovine viral diarrhea virus (BVDV) antigen was identified in an ear notch sample collected from a necropsied calf from group B. Subsequently, ear notch specimens from cattle in all 3 groups were tested for BVDV antigen. A significantly higher proportion of calves persistently infected with BVDV was identified in group B (8/295 [2.7%]), compared with the proportion in groups A and C combined (1/287 [0.3%]). Outbreaks of disease attributable to Salmonella Newport infection in beef cattle are unusual. Because of the immunosuppressive nature of BVDV, the possibility of animals persistently infected with BVDV within the herd should be considered during investigation of unusual outbreaks of infectious diseases.

Bovine Viral Diarrhea Virus Multiorgan Infection in Two White-Tailed Deer in Southeastern South Dakota

The susceptibility of wild ruminants, especially cervids, to bovine viral diarrhea virus (BVDV) has remained an enigma. Two white-tailed deer (Odocoileus virginianus) were submitted to the Animal Disease Research and Diagnostic Laboratory (ADRDL) in the fall of 2003 by the South Dakota Game Fish and Parks for chronic wasting disease (CWD) testing. Both animals were CWD negative. The animals were necropsied and histopathology, viral antigen detection, and virus isolation were performed. A noncytopathic (NCP) BVDV was isolated from the lungs and several other tissues of both animals. Formalin-fixed ear notches from both animals were positive for BVDV antigen by immunohistochemistry. The BVDV isolates were typed with the use of polymerase chain reaction in 5' untranslated region (UTR) and one isolate was typed a Type 2a and the other a Type 1b. Future field surveys to determine the incidence of BVDV along with experimental studies to determine if white-tailed deer fawns can be persistently infected with BVDV are needed.