scholarly journals Seroprevalence and risk factors of Neospora caninum and Bovine Viral Diarrhoea Virus in smallholder dairy cattle in Kenya

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
John VanLeeuwen ◽  
Joan Muraya ◽  
George Gitau ◽  
Dennis Makau ◽  
Bronwyn Crane ◽  
...  
Keyword(s):  
Risk Factors ◽  
Dairy Cattle ◽  
Neospora Caninum ◽  
Bovine Viral Diarrhoea Virus ◽  
Border Disease Virus ◽  
Bovine Viral Diarrhoea ◽  
Factors Associated ◽  
Border Disease ◽  
Diarrhoea Virus ◽  
Smallholder Dairy

Little is known of the risk factors associated with occurrence of Neospora caninum and Bovine Viral Diarrhoea Virus (BVDV) infection in Kenya. This cross-sectional study hypothesized that there are significant biosecurity measures associated with N. caninum and BVDV infections on smallholder dairy farms in Kenya that could be adopted to reduce seroprevalence and impacts. From 158 randomly selected farms in Meru County, Kenya, 470 serum samples were collected from dairy cattle (over six months of age and unvaccinated for these two pathogens). Sera were analyzed for antibodies to N. caninum and antibodies and antigens to BVDV. Data on risk factors were obtained through face-to-face interviews with the farmers. Multivariable logistic regression models were used to identify significant risk factors associated with seropositivity for the pathogens. The apparent seroprevalence of N. caninum, BVDV antibody, BVDV antigen, and co-infection with N. caninum and BVDV antibody and/or antigen were 35.1%, 47.1%, 36.2% and 18.5%, respectively. Risk factors associated with N. caninum antibody included: introducing milking cows into the farm, lending of cattle between farms, farm dogs having access to bovine aborted fetuses, and dogs whelping in the farm compound, with an interaction between the last two variables. BVDV antigen was associated with cattle having contact with pigs, and an interaction between cattle age and whether farms introduced new calves onto farms, and cattle age and whether visiting dairy farmers have access to the cow shed. Cows had higher odds of having BVDV antibodies compared to heifers. Factors associated with co-infection included cow parity, direct contact between dairy cattle, dogs and goats, and introducing new milking cows into the farms. Antibody and antigen results may be partly a function of classical swine fever virus or border disease virus interactions. Farmer education on these biosecurity measures is recommended, along with introduction of BVDV vaccination.

scholarly journals Molecular analysis of bovine viral diarrhoea virus isolates from South Africa

2003 ◽  
Vol 70 (4) ◽  
Author(s):  
N. Kabongo ◽  
C. Baule ◽  
M. Van Vuuren
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Calf Serum ◽  
Bovine Viral Diarrhoea Virus ◽  
Border Disease Virus ◽  
Foetal Calf Serum ◽  
Type I ◽  
Bovine Viral Diarrhoea ◽  
Border Disease ◽  
Diarrhoea Virus

The presence of bovine viral diarrhoea virus in South Africa has been confirmed by several serological surveys. However, little is known about its biological properties. Twenty five isolates obtained by isolation in tissue culture and detected by means of the antigen capture ELISA from clinically sick cattle and from foetal calf serum in South Africa were characterized on the basis of analysis of the 5' non-translated (NTR) region of the genome. A reverse-transcription polymerase chain reaction (RT-PCR) was used to amplify specific sequences from the 5'NTR of the genome. The oligonucleotide primers corresponding to positions 105-125 and 399-378, respectively, in the sequence of BVDV strain NADL were used to generate the PCR products. Both strands were sequenced directly with these primers and fluorescence-labelled dideoxynucleotides in an automated nucleic acid sequencer. Reference strains of pestiviruses [(BVDV type I, BVDV type II, border disease virus (BDV) and hog cholera virus (HCV)] and isolates from a previous investigation on BVDV in southern Africa were included for comparative purposes. All the BVDV strains obtained during this study belong to subgroups of BVDV genotype I. No association could be demonstrated between the geographic origin of the isolates. A number of isolates formed another branch separate from the existing branches Ia, Ib and Ic. These findings suggest that extensive genetic diversity can be found within BVDV type I isolates from southern Africa. Isolates that group with the classical BVDV type I strains, particularly of American origin, coexist with variants that appear to represent a local genetic pool and or variants evolving from the classical strains.

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

2021 ◽  
Vol 8 ◽  
Author(s):  
Matthias Schweizer ◽  
Hanspeter Stalder ◽  
Anja Haslebacher ◽  
Martin Grisiger ◽  
Heinzpeter Schwermer ◽  
...  
Keyword(s):  
Horizontal Transmission ◽  
Bovine Viral Diarrhoea Virus ◽  
Control Programme ◽  
Economic Losses ◽  
Border Disease Virus ◽  
Cattle Population ◽  
Bovine Viral Diarrhoea ◽  
Main Challenge ◽  
Border Disease ◽  
Diarrhoea 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.

scholarly journals Serological survey of British sheep flocks for evidence of exposure to ovine pestiviruses

2018 ◽  
Vol 183 (7) ◽  
pp. 220-220 ◽  
Author(s):  
Amy Jennings ◽  
Emily Gascoigne ◽  
Alastair Macrae ◽  
Elizabeth Burrough ◽  
James Patrick Crilly
Keyword(s):  
Great Britain ◽  
Metabolic Profiling ◽  
Bovine Viral Diarrhoea Virus ◽  
Border Disease Virus ◽  
Serological Survey ◽  
Bovine Viral Diarrhoea ◽  
Sheep Flock ◽  
Seropositive Animal ◽  
Border Disease ◽  
Diarrhoea Virus

Ovine pestiviruses have the potential to reduce productivity in the British sheep flock. However, their prevalence and impact are currently poorly understood. This study aimed to estimate the exposure to pestiviruses in adult breeding ewe stock. Blood samples collected for metabolic profiling before lambing were tested using an ELISA that detected antibodies raised to both bovine viral diarrhoea virus and Border disease virus. A group of 15 animals were tested per flock. A total of 34 farms were tested, of which 13 had at least one seropositive animal. In those positive flocks between one and nine of the animals tested antibody-positive. Positive flocks were identified in all regions of Great Britain. This work suggests that exposure to ovine pestiviruses is widespread, and that it is timely to investigate flock-level prevalence and possible production impacts of endemic infection.

Cytopathogenicity markers in the genome of Hungarian cytopathic isolates of bovine viral diarrhoea virus

2005 ◽  
Vol 53 (1) ◽  
pp. 125-136 ◽  
Author(s):  
Á. Bálint ◽  
Claudia Baule ◽  
S. Kecskeméti ◽  
I. Kiss ◽  
S. Belák
Keyword(s):  
Amino Acid ◽  
Genetic Recombination ◽  
Bovine Viral Diarrhoea Virus ◽  
Amino Acid Position ◽  
Border Disease Virus ◽  
Nucleotide Position ◽  
Bovine Viral Diarrhoea ◽  
Border Disease ◽  
Diarrhoea Virus ◽  
Genomic Regions

Since genetic recombination is a major factor in the evolution of the cytopathogenic (cp) bovine viral diarrhoea virus (BVDV) biotypes, in this study the cytopathogenicity markers were investigated in the genomes of two cp BVDV strains recently isolated from mucosal disease (MD) cases in Hungary. In the genome of strain H4956, a Jiv-like insertion was found similar to those described in reference strain NADL and in other BVDV 1, BVDV 2 and border disease virus (BDV) strains. The 133 amino acid Jiv-like sequence is inserted at nucleotide position 4984 (amino acid position 1533), 9 nucleotides upstream of that of strain NADL. The insertion showed 96% amino acid sequence identity with the cellular Jiv protein. In the genome of cp BVDV strain H115/PCR, an ubiquitin-containing duplication was found. The duplicated sequence started at nucleotide position 7978 (amino acid 2531) in the NS4B gene. The duplication contained a complete ubiquitin monomer of 76 amino acids and the complete NS3 gene starting at nucleotide position 5153 (amino acid 1589), which corresponds to the first N-terminal amino acid of NS3. The duplication was located further downstream of the known ubiquitin-containing genomic regions of cp BVDV strains, and it consisted of the shortest inserted nucleotide sequence. The insertions and duplication of strains H4956 and H115/PCR further confirmed that recombinations occurring at positions A and B are the most common mechanisms leading to the development of BVDV cytopathogenicity.

Reproductive disorders in relation to Neospora caninum, Brucella spp. and bovine viral diarrhoea virus serostatus in breeding and dairy farms of central and southern Ethiopia

2012 ◽  
Vol 141 (8) ◽  
pp. 1772-1780 ◽  
Author(s):  
K. ASMARE ◽  
F. REGASSA ◽  
L. J. ROBERTSON ◽  
A. D. MARTIN ◽  
E. SKJERVE
Keyword(s):  
Dairy Cattle ◽  
Neospora Caninum ◽  
Bovine Viral Diarrhoea Virus ◽  
Dairy Farms ◽  
Southern Ethiopia ◽  
Infectious Agents ◽  
Bovine Viral Diarrhoea ◽  
Reproductive Disorders ◽  
Blood Samples ◽  
Diarrhoea Virus

SUMMARYAbortion and stillbirth are important reproductive disorders in the dairy industry and are often caused by infectious agents. This study investigated whether bovine viral diarrhoea virus (BVDV), Brucella spp., and Neospora caninum are associated with abortion and/or stillbirth in dairy cattle in Ethiopia. Dairy cattle from 99 farms were categorized as cases (n = 134) or controls (n = 268) according to reproductive data. Blood samples were screened for antibodies for these infectious agents. The overall proportion of cattle that were seropositive for BVDV, Brucella spp., and N. caninum was 11·7%, 3·2%, and 17·2%, respectively. Seropositivity for BVDV and Brucella spp. was similar for cases and controls, but significantly more cases were seropositive for N. caninum (29·8%) than controls (10·8%). This is the first report demonstrating N. caninum is common in dairy cattle in Ethiopia, and is probably a greater impediment to reproductive success in Ethiopian dairy farms than either BVDV or Brucella spp.

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