The prevalence of antibodies to bovine viral diarrhoea/mucosal disease virus in African wildlife

Eradication of Bovine Viral Diarrhoea (BVD) in Cattle in Switzerland: Lessons Taught by the Complex Biology of the Virus

Bovine viral diarrhoea virus (BVDV) and related ruminant pestiviruses occur worldwide and cause considerable economic losses in livestock and severely impair animal welfare. Switzerland started a national mandatory control programme in 2008 aiming to eradicate BVD from the Swiss cattle population. The peculiar biology of pestiviruses with the birth of persistently infected (PI) animals upon in utero infection in addition to transient infection of naïve animals requires vertical and horizontal transmission to be taken into account. Initially, every animal was tested for PI within the first year, followed by testing for the presence of virus in all newborn calves for the next four years. Prevalence of calves being born PI thus diminished substantially from around 1.4% to <0.02%, which enabled broad testing for the virus to be abandoned and switching to economically more favourable serological surveillance with vaccination being prohibited. By the end of 2020, more than 99.5% of all cattle farms in Switzerland were free of BVDV but eliminating the last remaining PI animals turned out to be a tougher nut to crack. In this review, we describe the Swiss BVD eradication scheme and the hurdles that were encountered and still remain during the implementation of the programme. The main challenge is to rapidly identify the source of infection in case of a positive result during antibody surveillance, and to efficiently protect the cattle population from re-infection, particularly in light of the endemic presence of the related pestivirus border disease virus (BDV) in sheep. As a consequence of these measures, complete eradication will (hopefully) soon be achieved, and the final step will then be the continuous documentation of freedom of disease.

A Scoping Review of Viral Diseases in African Ungulates

(1) Background: Viral diseases are important as they can cause significant clinical disease in both wild and domestic animals, as well as in humans. They also make up a large proportion of emerging infectious diseases. (2) Methods: A scoping review of peer-reviewed publications was performed and based on the guidelines set out in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. (3) Results: The final set of publications consisted of 145 publications. Thirty-two viruses were identified in the publications and 50 African ungulates were reported/diagnosed with viral infections. Eighteen countries had viruses diagnosed in wild ungulates reported in the literature. (4) Conclusions: A comprehensive review identified several areas where little information was available and recommendations were made. It is recommended that governments and research institutions offer more funding to investigate and report viral diseases of greater clinical and zoonotic significance. A further recommendation is for appropriate One Health approaches to be adopted for investigating, controlling, managing and preventing diseases. Diseases which may threaten the conservation of certain wildlife species also require focused attention. In order to keep track of these diseases, it may be necessary to consider adding a “Wildlife disease and infection” category to the World Organisation for Animal Health-listed diseases.

First report on serological evidence of bovine viral diarrhea virus (BVDV) infection in farmed and free ranging mithuns (Bos frontalis)

Despite reports of BVDV infection in several domestic and wild ruminants, no information exists for mithun (Bos frontalis) species. Hence, this study was undertaken to determine prevalence of BVDV infection in mithuns, which contribute significantly to local economy in the North Eastern region of India. Blood and serum samples were collected between 2013 and 2016 from mithuns (n = 466) belonging to the states of Nagaland, Mizoram, and Arunachal Pradesh. Serum samples were tested for BVDV antibodies by a commercial ELISA and leukocytes were tested for BVDV by real-time RT-PCR. The overall true seroprevalence rate was 13.1% (95% confidence interval, CI: 6.9-17.8%) with higher prevalence in mithuns reared under semi-intensive system (27.5%) than in free-ranging mithuns (7.6%). Among the three states, seroprevalence (16.2%) was highest in Nagaland, while prevalence rates varied markedly among geographical locations. Age-wise data showed highest seroprevalence rate in >6-year-old animals (20.6%) than 2-6 years old (16.9%), 6 months-2 years old (8.5%), and <6-month-old animals (11.3%). The seroprevalence was higher in males (20.9%) than in females (12.1%). Among the four mithun strains, higher prevalence was evident in Manipur (30.3%) than Arunachal (21.3%), Nagaland (11.7%), and Mizoram strain (10.2%). However, no BVDV genomic RNA could be detected. The results provide first serological evidence of BVDV infection in mithun species and extend the knowledge on BVDV host range. The baseline data will help further investigations on epidemiology of BVD in mithun and its impact on mithun production.

Challenges in Identifying and Determining the Impacts of Infection with Pestiviruses on the Herd Health of Free Ranging Cervid Populations

Although most commonly associated with the infection of domestic livestock, the replication of pestiviruses, in particular the two species of bovine viral diarrhea virus (BVDV), occurs in a wide range of free ranging cervids including white-tailed deer, mule deer, fallow deer, elk, red deer, roe deer, eland and mousedeer. While virus isolation and serologic analyses indicate that pestiviruses are circulating in these populations, little is known regarding their impact. The lack of regular surveillance programs, challenges in sampling wild populations, and scarcity of tests and vaccines compound the difficulties in detecting and controlling pestivirus infections in wild cervids. Improved detection rests upon the development and validation of tests specific for use with cervid samples and development and validation of tests that reliably detect emerging pestiviruses. Estimation of impact of pestivirus infections on herd health will require the integration of several disciplines including epidemiology, cervid natural history, veterinary medicine, pathology and microbiology.

Serological survey of bovine viral diarrhoea virus in Namibian and South African kudu (Tragelaphus strepsiceros) and eland (Taurotragus oryx)

Bovine viral diarrhoea virus (BVDV) is a pestivirus that affects members of the order Artiodactyla, including members of the subfamily Bovinae. Little is known about the seroprevalence of BVDV in southern Africa, especially the prevalence in wild ruminant populations such as kudu (Tragelaphus strepsiceros). A handful of random surveys suggested that seroprevalence ranged between 6% and 70% in southern African wild ruminants. The present study aimed to determine the seroprevalence of BVDV amongst kudu and eland (Taurotragus oryx) from Namibia and South Africa. A BVDV-specific enzyme-linked immunosorbent assay was performed on 50 serum samples from kudu and eland from South Africa and Namibia. The seroprevalence of BVDV in South African kudu was 71%, identical to that in Namibian kudu. The seroprevalence in Namibian eland was 40%. The kudu and cattle farming (free ranging) regions in Namibia predominantly overlap in the central regions, ensuring ample opportunity for cross-species transmission of BVDV. It is therefore important to determine the true prevalence of BVDV in southern Africa in both domesticated and wild animals. In addition, a potential link between BVDV incidence and a devastating rabies epidemic in Namibian kudu was proposed and such a notion could be supported or discredited by comparative prevalence data.

Bovine viral diarrhea virus: global status

Despite the success of regional bovine viral diarrhea viruses (BVDV) eradication programs, infections remain a source of economic loss for producers. The wide variation among BVDV results in differences in genotype, biotype, virulence, and types of infections. BVDV infect a range of domestic and wild ruminants. Clinical presentation varies depending on strain of virus, species of host, immune status of host, reproductive status of host, age of host, and concurrent infections. Recent advances in BVDV research and diagnostics have led to the development of regional eradication/control programs, the most efficacious of which focus on biosecurity, surveillance, and control.

Bovine viral diarrhea virus infections in heterologous species

Infections with Bovine viral diarrhea virus (BVDV) are not limited to cattle, but may be detected in various species in the mammalian order Artiodactyla. Despite epidemiological evidence of BVDV infections in species other than cattle, current knowledge regarding the impact of BVDV on heterologous species is incomplete. In heterologous hosts, BVDV infections with clinical signs analogous to those in cattle have been described and include disease of multiple organ systems, most notably the reproductive tract and immune system. Clinical infections may negatively impact the health and well-being of heterologous species, including camelids and captive and free-ranging wildlife. Of additional importance are BVDV infections in small ruminants and swine where difficulties arise in laboratory testing for Border disease virus (BDV) and Classical swine fever virus (CSFV), respectively. Pestiviruses are antigenically closely related and their cross-reactivity requires additional efforts in virological testing. In cattle populations, persistently infected animals are considered the main source of BVDV transmission. This phenomenon has also been detected in heterologous species, which could facilitate reservoirs for BVDV that may be of great importance where control programs are in progress. This review summarizes the current epidemiological and clinical knowledge on heterologous BVDV infections and discusses their implications.

First report of BVDV circulation in sheep in Argentina

Pestiviruses are capable of infecting a wide range of animals within the order Artyodactila. Currently, the genus Pestivirus includes Bovine Viral Diarrhea Virus 1 (BVDV-1) and 2 (BVDV-2), Border Disease Virus (BDV), and Classical Swine Fever Virus (CSFV). BVDV-1, BVDV-2 and BDV are able to cross species barrier to infect a wide range of hosts, whereas CSFV is restricted to domestic pigs and wild boars. In Argentina, 70% of cattle are seropositive to BVDV. Although there were some serological studies in llamas, alpacas and buffaloes, no reports existed about the circulation of BVDV in sheep in Argentina. Based on these, 54 blood samples of healthy ovines were analysed by serology. The results showed that 46.3% of the analysed sheep were seropositive to BVDV-1, 13% to BVDV-2 and 20.4% for both BVDV-1 and BVDV-2. The molecular analysis confirmed the presence of BVDV-1a in some samples.

Evidence for persistent Bovine viral diarrhea virus infection in a captive mountain goat (Oreamnos americanus)

Bovine viral diarrhea (BVD) viruses are pestiviruses that have been isolated from domestic and wild ruminants. There is serologic evidence of pestiviral infection in more than 40 species of free-range and captive mammals. Vertical transmission can produce persistently infected animals that are immunotolerant to the infecting strain of Bovine viral diarrhea virus (BVDV) and shed virus throughout their lives. Seven species (white-tailed deer, mouse deer, eland, domestic cattle, alpaca, sheep, and pigs) have been definitively identified as persistently infected with BVDV. This study provides serological, molecular, immunohistochemical, and histological evidence for BVDV infection in 2 captive mountain goats from a zoological park in Idaho. The study was triggered by isolation of BVDV from tissues and immunohistochemical identification of viral antigen within lesions of a 7-month-old male mountain goat (goat 1). Blood was collected from other mountain goats and white-tailed and mule deer on the premises for BVDV serum neutralization, viral isolation, and reverse transcription polymerase chain reaction. One 3-month-old mountain goat (goat 2) was antibody negative and BVDV positive in serum samples collected 3 months apart. This goat subsequently died, and though still antibody negative, BVDV was isolated from tissues and identified by immunohistochemistry within lesions. Sequencing and phylogenetic analysis identified the isolates as BVDV-2. These findings provide evidence of persistent infection in a mountain goat, underscoring the need for pestivirus control strategies for wild ruminants in zoological collections.

Identification of bovine viral diarrhea virus type 1 in yaks (Bos poephagus grunniens) in the Himalayan region

Since cattle are widely infected by bovine viral diarrhea virus (BVDV) in India, we searched for pestivirus infection in yaks. Of 71 pure and crossbred yaks from Himalayan region, pestivirus antigen was detected by Ag-ELISA in three animals. Pestivirus in leukocyte and cell culture isolated virus samples originating from positive yaks was also confirmed by RT-PCR using panpestivirus specific primers selected from 5'-untranslated region (5' UTR). The 5' UTR, N(pro) and E2 regions were sequenced and used for genetic typing. Phylogenetic analysis revealed that pestiviruses detected in three Himalayan yaks were similar genetically, belonging to BVDV-1. Antigenic characterisation of yak pestivirus also confirmed the typing as BVDV-1. This is the first report on the identification of BVDV type 1 in yaks.

Evidence for positive selection on the E2 gene of bovine viral diarrhoea virus type 1

Despite the growing interest in the molecular epidemiology of pestivirus, there have been few attempts to determine which regions of the pestivirus genome are subject to positive selection, although this may be a key indicator of the nature of the interaction between host and virus. By using likelihood-based methods for phylogenetic inference, the positive selection pressure of BVDV-1 E2 gene were assessed and a site-by-site analysis of the dN/dS ratio was performed, to identify specific codons undergoing diversifying positive selection. The overall omega was 0.20, indicating that most sites were subject to strong purifying selection and five positively selected sites (886, 888, 905, 944, and 946) were identified. It is surprising to find that all the potential positively selected sites fall within the C-terminal of E2, and out of the N-terminal of E2 which is thought to be surface-exposed and therefore prime targets for host antibody response. In conclusion, these results suggest that selection favoring avoidance of antibody recognition has not been a major factor in the history of BVDV-1. Further analysis is necessary to see if amino acid substitutions in the BVDV-1 positively selected sites can lead to change of host tropism or\and escape from epitope-specific CD8 T-cell response.

Pestiviruses in wild animals

Pestiviruses are not strictly host-species specific and can infect not only domestic but also wild animals. The most important pestivirus, CSFV, infects domestic pigs and wild boars, which may cause a major problem for successful CSFV eradication programmes. Mainly BVDV specific antibodies have been reported in captive and free-living animals. Virus has been isolated from some of these animal species, but since BVDV can contaminate cell cultures and foetal calf serum, early reports of BVDV isolation have to be considered with caution. Genetic typing of early pestivirus isolates from wild species revealed that the majority were BVDV-1. Of the pestiviruses identified so far three species (CSFV, BVDV-1, giraffe pestivirus) and three genotypes (BDV-2, BDV-4, pronghorn) appear to circulate in wildlife animal populations. The potential for pestiviruses to spread between farm animals and free-living animals is discussed as are epidemiological and technical problems, and the future direction of research.

Seroprevalence of pestivirus in four species of alpine wild ungulates in the High Valley of Susa, Italy

Wildlife, once infected, can serve as a reservoir of infectious diseases that form a constant threat to domestic livestock. To make control and eradication programs successful in the long-term, presence of pestivirus in wildlife populations should be monitored. The goal of this study was to investigate seroprevalence of pestivirus in four alpine wild ungulates in the High Valley of Susa, north-west Italy. Species studied were: red deer (Cervus elaphus), roe deer (Capreolus capreolus), wild boar (Sus scrofa) and chamois (Rupicapra rupicapra). A further goal was using virus neutralisation tests (VNT) for four strains of pestivirus in chamois and wild boar. Three hundred and seventy-five serum samples collected during the hunting season of 1999 were tested for pestivirus specific antibodies. Positive sera of chamois and wild boar were subsequently tested in a VNT with four major subtypes of pestivirus, and virus isolation was performed. No antibodies were found in the 73 samples of roe deer, while 7 (12.5%), 8 (5.9%) and 28 (25.5%) of 56, 136 and 110 samples of wild boar, red deer and chamois were ELISA-positive, respectively. Different ranges of titers were found in the VNT and no pestivirus was isolated in the ELISA-positive wild boar and chamois samples. Several possibilities, which might explain the high seroprevalence in chamois are discussed. Pestivirus antibodies were found in three out of four large alpine ungulates in the High Valley of Susa. Seroprevalence was particularly high in chamois. Further investigation is needed to characterise the pestiviruses that circulate in these animals.

Characterization of a novel pestivirus originating from a pronghorn antelope

A unique pestivirus, isolated from a pronghorn antelope (Antilocopra americana), was characterized. Serum neutralization studies suggested that this virus was antigenically related to pestiviruses. Genomic characteristics, unique to pestiviruses, indicated that this virus belongs to the Pestivirus genus. These characteristics included the organization of the 5' untranslated region (5'-UTR), the presence and length of a viral Npro coding region, conservation of cysteine residues in Npro, conservation of predicted amino acid sequences flanking the cleavage sites between viral polypeptides Npro and C and between C and Erns and conservation of predicted hydrophobicity plots of Npro protein. While this data indicated the virus belongs to the Pestivirus genus, phylogenetic analysis in 5'-UTR, Npro and E2 regions suggested that it is the most divergent of the pestiviruses identified to date. This conclusion was also supported by the amino acid identity in coding regions. The corresponding values were much lower for the comparison of pronghorn pestivirus to other pestivirus genotypes than only between previous recognized genotypes. These results suggest the virus isolated from pronghorn antelope represents a new pestivirus genotype. It also represents the only pestivirus genotype first isolated from New World wildlife.

Genetic and antigenic characterization of an atypical pestivirus isolate, a putative member of a novel pestivirus species

The genus Pestivirus within the family Flaviviridae currently consists of four different main species: Classical swine fever virus, Bovine viral diarrhea virus types 1 and 2 and Border disease virus. A fifth tentative species is represented by an isolate from a giraffe. In this study, a completely new pestivirus, isolated from a batch of fetal calf serum that was collected in Brazil, is described. It is proposed that the isolate D32/00_'HoBi' may constitute a novel sixth pestivirus species, because it is genetically, as well as antigenically, markedly different from all other pestiviruses. Based on the entire N(pro)- and E2-encoding sequences, identities of <70 % to all other pestivirus species were determined. Similarly, cross-neutralization and binding studies using antisera and mAbs revealed marked antigenic differences between D32/00_'HoBi' and all other pestiviruses.

Genetic and antigenic characterization of novel pestivirus genotypes: implications for classification

Currently, the genus Pestivirus comprises the four approved species Bovine viral diarrhea virus 1 (BVDV-1), BVDV-2, Classical swine fever virus (CSFV), and Border disease virus (BDV) and one tentative fifth species represented by a single strain (H138) isolated from a giraffe in Kenya more than 30 years ago. To further address the issue of heterogeneity of pestiviruses we have determined the entire N(pro) and E2 coding sequences for several new pestivirus isolates. Interestingly, phylogenetic analysis revealed that one pestivirus isolated in the 1990s in Africa is closely related to strain H138. Moreover, several novel pestiviruses isolated from sheep group together with the previously described strain V60 (Reindeer-1) isolated from a reindeer, whereas one ovine pestivirus strain (Gifhorn) significantly differs from all previously described pestiviruses, including BDV. We propose to term these mainly sheep-derived pestiviruses BDV-2 (V60-like isolates) and BDV-3 (Gifhorn); consequently, the "classical" BDV isolates should be termed BDV-1. As an additional criterion for segregation of pestiviruses, the antigenic relatedness of pestivirus isolates covering all observed major genotypes was studied by cross-neutralization assays. Analysis of the antigenic similarities indicated the presence of seven major antigenic groups corresponding to BVDV-1, BVDV-2, CSFV, BDV-1, BDV-2, BDV-3, and "giraffe". Taking into account the host origin, the lack of differences concerning the course of disease, and the results of our genetic and antigenic analyses, we suggest that BDV-1, BDV-2, and BDV-3 should be considered as major genotypes within the species BDV.

Evidence for the presence of two novel pestivirus species

The genus Pestivirus of the family Flaviviridae comprises four species, namely Bovine viral diarrhea virus-1 (BVDV-1), BVDV-2, Border disease virus (BDV), and Classical swine fever virus (CSFV). Comparative analyses of partial sequences have suggested that pestivirus isolates from giraffe (Giraffe-1) and reindeer (Reindeer-1) are distinct from the established species (Becher et al., Virology 262, 64--71, 1999). In this study, we report the complete genomic sequences of pestivirus strains Giraffe-1 and Reindeer-1. Comparative sequence analyses revealed considerable differences among Giraffe-1, Reindeer-1, and the currently recognized pestivirus species. Phylogenetic analysis of the complete coding sequences of these two strains, along with 13 other sequences representing the four established species, indicated that CSFV, BDV, and Reindeer-1 have bifurcated from one common branch and BVDV-1 and BVDV-2 from another. In the former branch BDV and the pestivirus from reindeer are more similar to each other than to CSFV. The giraffe pestivirus is equally distinct from both major branches. In addition, the antigenic relatedness of pestivirus isolates covering the observed major genetic groups was studied by cross-neutralization assays. A clustering procedure on the basis of antigenic differences indicated the presence of six major groups corresponding to the genetically defined groups. Taken together, the results of our analyses addressing both nucleotide sequence relatedness and serological relatedness argue for the inclusion of Giraffe-1 and Reindeer-1 as the first members of two separate novel species within the genus Pestivirus.

Diversity among bovine pestiviruses

Bovine viral diarrhoea virus (BVDV) isolates are characterized by an important genetic, antigenic and pathogenic diversity. The emergence of new hypervirulent BVDV strains in North America has provided clear evidence of pathogenic differences between BVDV strains. The origin of BVDV diversity is related to high mutation rate occurring in RNA viruses but the consequences of mutations obviously depend on the genes which are involved. Mutations in genes encoding for structural proteins of immunological importance may have practical implications. Knowledge of BVDV diversity is important for understanding the wide variety of pathogenesis of diseases caused by the virus, for monitoring the epidemiology of the different types and for the design of optimum laboratory tests and vaccines. This review focuses on the origin and consequences of BVDV diversity with regard to pathogenesis, biotypes, and antigenic and genetic variations.

Prevalence of antibodies to bovine viral diarrhoea virus and/or border disease virus in domestic ruminants

A total of 62 sera collected from cattle, buffalo, sheep, goats and camels were investigated for the presence of antibodies to bovine viral diarrhoea (BVD) virus. The prevalence of neutralizing antibodies to BVD virus was 49.2, 52.0, 27.5, 31.4 and 52.5% in cattle, buffalo, sheep, goats and camels, respectively. The positive sera were titrated against BVD virus (BVDV) strains NADL and Oregon C24V; the latter is closely related to border disease (BD) virus. The frequency distributions of the antibody titres to both strains are presented. The statistical analysis shows no significant difference between the antibody titres to BVDV strains NADL and Oregon C24V in cattle, buffalo, sheep, goats and camels. On the other hand antibody titres to BVDV were significantly higher (P < 0.05) in cattle and buffalo in comparison with sheep, goats and camels. The cell-bound immunoassay (CBIA) is a serological rest established for the detection and titration of antibodies to BVD virus and BD virus. The percentage of agreement between the CBIA and the neutralizing peroxidase-linked antibody (NPLA) test was 96.1 and 95.3% in cattle and buffalo, respectively. The sensitivity of the CBIA in comparison with the NPLA was 100% while the specificity was 92.3 and 90.3% when testing the sera of cattle and buffalo, respectively. The method is easy to perform, cheap and suitable for the conditions in Egypt.

Ruminant pestivirus infections in animals other than cattle and sheep

The current knowledge on infection with ruminant pestiviruses in animals other than cattle and sheep and reviewed. Natural infection is found to occur in goats, in captive and free-living ruminants, as well as in pigs. The viral agent, susceptible species, epidemiology, clinicopathologic lesions, pathogenesis, diagnosis, control, and consequences for control programs in domestic ruminants are discussed.

Sero-prevalences of selected cattle diseases in the Kafue flats of Zambia

Sera from five traditionally managed herds grazing in the Kafue flats were tested for antibodies to bovine viral diarrhoea-mucosal disease (BVD-MD), parainfluenza 3 (PI3), infectious bovine rhinotracheitis-infectious pustular vulvovaginitis (IBR-IPV), bovine adenovirus 3 (BAV3) and Bluetongue (BT). The sero-prevalences of the first four diseases were respectively 76.2, 94.4, 42.1 and 87.4%. Five samples (2.3%) gave doubtful reactions for BT. Prevalences of 28.5% for brucellosis, 14% for Rift Valley fever (RFV), 0.9% for Q fever and 11.2% for chlamydiosis were also recorded. Significantly higher values for BVD-MD (p less than 0.005), IBR-IPV (p less than 0.01) and brucellosis (p less than 0.05) were found in animals over 1 year of age. No differences were recorded between herds or between male and female animals. The high concentration of wild and domestic ruminants grazing together in the flood plains during the dry season may be a major determinant of the high values observed. Traditional farmers, slaughterhouse workers and other people involved in livestock production are particularly at risk of contracting brucellosis and RVF because of the high prevalences in cattle and local habits favourable to their transmission.

Pathogenesis of mucosal disease and molecular aspects of bovine virus diarrhoea virus

Studies carried out over three decades, on the pathogenesis and epidemiology of bovine virus diarrhoea virus (BVDV), have provided the basis for our understanding of the aetiology of mucosal disease. Experimental reproduction of the disease has demonstrated the mechanism of sequential infection and the role of the two virus biotypes. The need for "homogeneity" between the biotypes, causing mucosal disease, has demonstrated the precision of immunotolerance. The origin of the cytopathogenic biotype remains unclear but molecular studies may provide the solution. Recent findings have revealed the absence of an 80 kDa polypeptide in the non-cytopathogenic isolates. This protein is related to the 120 kDa polypeptide that is present in both biotypes. Genomic sequences for two isolates have been reported. An extensive homology to the protein ubiquitin has been identified only within the Osloss sequence in the region flanking coding sequences for the 80 kDa and 120 kDa proteins. Advances in the development of molecular gene probes and monoclonal antibodies will provide new tools for furthering our understanding of the pathogenesis, epidemiology and interrelationships of pestiviruses that infect pigs, cattle and sheep.

Prevalence of antibodies to bovine virus diarrhoea-mucosal disease virus in Tanzanian cattle

A serological survey to determine the prevalence of antibodies to bovine virus diarrhoea-mucosal disease (BVD-MD) virus was conducted on 419 bovine serum samples originating from 18 of 20 regions (except Mwanza and Shinyanga) of the Tanzania mainland. The sera were a small proportion of samples collected for the appraisal of immune response to rinderpest vaccination. The survey indicated that the virus is prevalent in cattle populations and approximately 12% of sera tested contained demonstrable neutralising antibodies against BVD-MD virus.