Effects of experimental infection with Border disease virus on lymphocyte subpopulations in the peripheral blood of lambs

Hussin, Ainulkhir; Woldehiwet, Z.

doi:10.1016/0034-5288(94)90105-8

Cited by 5 publications

(2 citation statements)

References 14 publications

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“…This is what has been described in the fattening workshops of young sheep in the Roquefort basin during the 2010–2013 epizootic [ 6 ]. These superinfections are explained by the capacity of BDV to induce a transient but severe leukopenia [ 11 , 16 , 17 , 18 ]. In this study, the BDV-6 challenge induced a marked leukopenia between D+2 and at least D+10 in naïve sheep.…”

Section: Discussionmentioning

confidence: 99%

Vaccination of Sheep with Bovine Viral Diarrhea Vaccines Does Not Protect against Fetal Infection after Challenge of Pregnant Ewes with Border Disease Virus

Meyer

Combes²,

Teillaud

et al. 2021

Vaccines

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Border Disease (BD) is a major sheep disease characterized by immunosuppression, congenital disorders, abortion, and birth of lambs persistently infected (PI) by Border Disease Virus (BDV). Control measures are based on the elimination of PI lambs, biosecurity, and frequent vaccination which aims to prevent fetal infection and birth of PI. As there are no vaccines against BDV, farmers use vaccines directed against the related Bovine Viral Diarrhea Virus (BVDV). To date, there is no published evidence of cross-effectiveness of BVDV vaccination against BDV infection in sheep. We tested three commonly used BVDV vaccines, at half the dose used in cattle, for their efficacy of protection against a BDV challenge of ewes at 52 days of gestation. Vaccination limits the duration of virus-induced leukopenia after challenge, suggesting partial protection in transient infection. Despite the presence of BDV neutralizing antibodies in vaccinated ewes on the day of the challenge, fetuses of vaccinated and unvaccinated sheep were, two months after, highly positive for BDV RNA loads and seronegative for antibodies. Therefore, BVDV vaccination at half dose was not sufficient to prevent ovine fetal infection by BDV in a severe challenge model and can only be reconsidered as a complementary mean in BD control.

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Section: Discussionmentioning

confidence: 99%

Vaccination of Sheep with Bovine Viral Diarrhea Vaccines Does Not Protect against Fetal Infection after Challenge of Pregnant Ewes with Border Disease Virus

Meyer

Combes²,

Teillaud

et al. 2021

Vaccines

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“…However, these results did not show differences in the white blood cell counts. This may be explained because the drop in lymphocyte counts is very short in time (3-7 days post-infection in experimental infections (Hussin and Woldehiwet 1994), and the different moment in which lambs become infected in natural conditions. In experimental BdV infection, no significant differences in growths were reported (Thabti and others 2002).…”

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confidence: 99%

Natural border disease virus infection in feedlot lambs

et al. 2014

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Border disease is caused by border disease virus (BdV, a pestivirus from the family Flaviviridae) infection in sheep and goats (Vantsis and others 1976). BdV infection causes sizeable economic losses in sheep production around the world. In Spain, serological surveys have found 100 per cent flocks and 8-93 per cent sheep seropositive, respectively (Valdazo-González and others 2006). Bd is considered a congenital disease, but infections in healthy animals at all age groups may also occur. These are named acute infections and are characterised by transitory leucopaenia and fever associated with viraemia (Nettleton and others 1998). The aim of this study was to evaluate the impact of these acute infections in lambs in a commercial feedlot. A longitudinal observational study in a feedlot located in Aragon (Spain) was carried out. Lambs were supplied to the feedlot at minimum 10 kg bodyweight (BW) (45 days old), housed in groups of 250-300 per pen and slaughtered at 25-35 kg BW (about 45 days later). Thirty-six male lambs were randomly selected, ear-tagged, weighed, clinically evaluated and sampled on days: 0 (day lambs entered the feedlot), 14, 27 and 41. From each lamb, whole blood in anticoagulant solution and serum samples for haematological, virological and serological studies were taken. Haematological analysis with an electronic counter (Sci Animal Blood Counter, divasa Farmavic S.A.) was performed. rNA was extracted from blood using QIAamp Viral rNA Mini Kit (Qiagen) following the manufacturer's indications. reverse transcriptase (rT)-PCr test as described using the panpestivirus primer pair 324/326 and adding 50 ng of rNA template in each reaction was carried out (Vilcek and others 1994). Additionally, a commercial blocking eLISA (CIVTeST P80, Laboratorios HIPrA S.A.) in serum samples to detect antibodies against p80 following the manufacturer's specifications was used. Any lamb with a positive result to any test (rT-PCr or eLISA) was considered a BdV infected lamb (BdV+). Clinical parameters between groups according to BdV infection were compared by χ 2 test. Haematological parameters were tested by repeated-measure non-parametric Friedman test. Live weight and average daily gain (AdG) differences between the groups of lambs were analysed by independent samples t test. Statistical analyses in SPSS 18.0 software (SPSS, IBM) were performed. A total of 20 lambs were positive to the BdV infection, 17 lambs by rT-PCr and 5 by eLISA test (Table 1). Three lambs were positive

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