Border Disease Of Sheep Research Articles

The Border Disease virus (BDV) prevalence and genetic typing in ruminant flocks in Turkey.

This study aims to update current data regarding Border Disease in sheep and goats, determine the first prevalence of BDV in cattle and identify its circulated genotype in Turkey. For this purpose, 100 sheep, 20 goats and 193 cattle aborted fetuses sent for diagnosis to Samsun Veterinary Control Institute between 2015 and 2017 were analyzed in terms of pestivirus by Ag‑ELISA, BDV by Real‑Time test (RT‑PCR) and Conventional RT‑PCR test. The rate of pestivirus positive animals was found at 50.26% (97/193) in cattle, 58% (58/100) in sheep and 55% (11/20) in goats by the pestivirus Ag‑ELISA test. Total of 58 Ag‑ELISA positive sheep were tested by Real‑Time RT‑PCR and conventional RT‑PCR tests. End of the tests, one sheep sample (1.72%) was found BDV positive by Real‑Time RT‑PCR test and three sheep (5.17%) and one cattle (1.03%) samples were detected as BDV positive by conventional RT‑PCR test. BDV positivity was not detected in goats in this research. All samples that were found positive by conventional RT‑PCR test and Real‑Time RT‑PCR test were genotyped by phylogenetic sequence analysis, and obtained results showed that BDV‑3 and BDV‑7 genotypes of BDV in sheep and BVDV‑1 genotype in cattle circulated in the investigated area. The sequence analysis results revealed that conventional RT‑PCR and Real‑Time RT‑PCR tests detected genotype BDV‑3, while genotype BDV‑7 was only detected by conventional RT‑PCR test in sheep abortion materials. Additionally, it was found that one bovine specimen was BDV positive by conventional PCR, but the same sample was identified as BVDV‑1 at sequence analysis. The obtained data of this study showed that new probes should be designed using our local strains for BDV diagnosis by Real‑Time RT‑PCR assay, and cattle must be sampled for BDV screening, and PCR tests results should always be confirmed by sequence analysis.

Border disease of sheep and goats in Saudi Arabia

Border diseases is one of viral diseases that affect sheep and goats causing economic losses worldwide. The present study was intended to explore the existence of border disease infection in sheep and goats in two regions at the north of Saudi Arabia. Collected serum samples were 624 from 155 sheep and 217 goats in Hail and 144 sheep and 108 goats in Rafha regions at the north of Saudi Arabia. Antibodies against pestivirus were examined in collected sera using competitive ELISA. Overall found pestivirus antibodies were 18.4%. Sheep showed the highest sero-prevalence (20.7%). Within localities highest seroprevalence was seen in Rafha region. Obtained results points to the circulation of border disease infection in sheep and goats in the northern part of Saudi Arabia.

Pestivirus infection of sheep – testing times?

Bovine viral diarrhoea in cattle and border disease in sheep are caused by infection with the pestiviruses bovine viral diarrhoea virus (BVDV) and border disease virus (BDV), respectively, although either...

Border disease virus: time to take more notice?

PESTIVIRUSES are the cause of classical swine fever (CSF), bovine viral diarrhoea (BVD) and border disease in sheep. CSF has, for decades, been listed as an OIE notifiable disease, and...

Epidemiological Survey of Border Disease Virus among Sheep from Northern Districts of Japan

The first epidemiological survey of Border disease virus (BDV) was undertaken in small ruminants in Japan. Ovine sera, collected from the northern prefectures of Hokkaido, Aomori and Iwate, were examined for the presence of antibodies against BDV using the neutralization peroxidase-linked antibody test. Twenty-nine (17.6%) of one hundred and sixty-five samples were seropositive for BDV. Results were specific, excluding cross-reactions with bovine viral diarrhea virus (BVDV). Only one sample (0.6%) was positive for BVDV, and was negative for BDV. Despite serological evidence of virus circulation, there have been no clinical cases of border disease in sheep in Japan. Although no diagnostic measures were performed, the infection did not appear to be associated with a reduction in ewe fertility nor with lamb mortality.

ペスチウイルス

Members of the genus Pestivirus, are causative agents of economically important diseases for livestock and wild animals that occur worldwide, such as bovine viral diarrhea, classical swine fever, and border disease of sheep. Pestivirus have novel insertions of host genes in the viral genome and functions of unique viral proteins, N(pro) and E(rns), related to the pathogenicity although genomic structure is closely related to the other viruses of Flaviviridae family, especially hepatitis C virus. In this review, recent studies on the molecular basis of pathogenicity of pestivirus infections were summarized.

Genetic heterogeneity of pestiviruses of ruminants in Switzerland

We have genetically analyzed ruminant pestiviruses. All >150 bovine viral diarrhea (BVD) viruses isolated from cattle in Switzerland belonged to genotype 1, with subgenogroups e, h, k and b found in decreasing frequency. To date, representatives of subgenogroup k have been detected in Switzerland only. Despite serological evidence of Border disease in sheep, only few Border disease viruses have been isolated, all of which belong to the novel group 3. Serological evidence suggested that pestivirus infections may occur also in wild ruminants in Switzerland but no isolates are available for analysis. In addition, we describe two pestiviruses, one a cell culture contaminant and the other isolated from a buffalo, that cluster with a recently proposed novel pestivirus species.

Border Disease in Sheep

The current knowledge on border disease in sheep is reviewed. This is a congenital and teratogenic disorder induced by pestivirus. The history, etiology, epidemiology, clinical aspects, and pathologic lesions at postnatal and intrauterine infections (as well as in congenitally affected animals), pathogenesis, immunity, diagnosis, and control and prevention of the syndrome are discussed.

Le portage asymptomatique des pestivirus chez les ruminants

Pestiviruses are enveloped single-chain ribonucleic acid viruses with a positive polarity. Pestiviruses include the viruses of classical swine fever (hog cholera), Border disease of sheep, mucosal disease of cattle, and isolates obtained from wild animals, such as red deer (Cervus elaphus). Among ruminants, pestiviruses have developed a remarkable strategy for assuring their persistence. Through epigenetic transmission, they lead to the birth of asymptomatic carrier animals harbouring non-cytopathic variants, which become immunotolerant to the strain of virus present. The presence of a small number of asymptomatic carriers enables the virus to circulate within a herd by horizontal transmission, leading to the birth of a new generation of asymptomatic carriers.

Border disease of sheep: The disease in the newborn, adolescent and adult

Border disease (BD) is a condition of newborn sheep that results from congenital infection by a non-cytopathic pestivirus occurring during the first half of gestation. The expression of the virus is largely determined by the age of the fetus at the time of infection, producing four distinct disease syndromes: (1) early embryonic death, (2) abortion and stillbirth, (3) birth of lambs with malformations, and (4) birth of small, weak lambs, lacking characteristic clinical signs, but bearing features of immunosuppression. The effects of the virus infection during the developmental stages of the fetus are most apparent as distinctive clinical signs at the time of birth but a state of specific immuno-tolerance with associated virus persistence remains for the lifetime of the sheep. Although the clinical signs disappear with time, some effects of virus persistence may continue into adolescence and often into adulthood. Characteristic lesions are found in the nervous, endocrine, skeletal and integumentary, and immune systems.

Pathomorphological and immunohistological findings in progeny of goats experimentally infected with pestiviruses.

A total of 25 pregnant goats without neutralizing antibodies against BVD virus were inoculated with two different pestivirus isolates at eight different stages of gestation. In both infection groups, various malformations were observed in fetuses and neonates. In three twins with neutralizing antibodies against BVD virus leukoencephalomalacia occurred, characterized by gelatinous transformation in the cerebral hemispheres. These lesions were comparable to alterations described in alternative pathology of Border disease in sheep. Although the immunohistological findings are characteristic for immunological tolerance and viral persistence, viable offspring persistently infected with pestivirus was not observed.

Border disease in sheep caused by transmission of virus from cattle persistently infected with bovine virus diarrhoea virus

Two outbreaks of border disease occurred on farms with sheep flocks and breeding cattle. The infection of the pregnant sheep was probably caused by transmission of virus from calves persistently infected with non-cytopathic bovine virus diarrhoea virus (BVDV) which were kept in close confinement with the ewes during mid-pregnancy. Border disease was also induced experimentally in eight lambs by exposing their dams at 38 to 78 days of gestation to a heifer persistently infected with BVDV. Both the natural and the experimental infections were characterised by typical signs such as 'hairy-shaker' lambs and high lamb mortality. The diagnosis was confirmed by virus isolations from live-born lambs, seroconversion and pathology. The study supports the assertion that cattle persistently infected with BVDV and in close contact with pregnant sheep, are an important source of strains of virus capable of causing border disease.

Aetiology of Kawasaki disease.

Thirteen serum samples from nine children with Kawasaki disease and 23 control samples gave negative results on screening for antibodies to hog cholera virus, border disease of sheep, bovine diarrhoea virus, and equine arteritis virus. The sera from two children with Kawasaki disease were cytotoxic; a possible link with cytotoxin from Propionibacterium acnes is considered.

Border disease of sheep: Spinal cord morphometry

Semi-automated planimetry was used to determine cross-sectional areas of spinal grey and white matter by direct microscopy of paraffin sections of spinal cord from Border disease (BD) and normal lambs at segments C 4, C 8, T 6 and L 4. Spinal cord cross-sectional area was significantly reduced in cases of BD produced by either intramuscular or intranasal inoculation of ewes in the first half of pregnancy with Weybridge strains of BD virus. The reduction was apparent at all 4 levels and in both grey and white matter, though the white matter was the more severely affected. Spinal cord areas tended to be smaller in the progeny of ewes exposed earlier in gestation or to larger doses of virus, but these differences were not statistically significant.

Barlow, R.M./Patterson, D.S.P.: Border Disease of Sheep: a virus‐induced teratogenetic disorder. A collaborative review

Barlow, R.M./Patterson, D.S.P.: Border Disease of Sheep: a virus‐induced teratogenetic disorder. A collaborative review

Clinical variations of border disease in sheep according to the source of the inoculum

Non-cytopathogenic pestivirus obtained from lambs with border disease, with or without nervous signs, was inoculated into pregnant ewes at 57 to 65 days of gestation. Live lambs born to inoculated ewes were clinically identical to the lambs from which virus was obtained, ie, either a hairy birth coat with central nervous system disturbance or a hairy birth coat without central nervous system disturbance.

Some Interactions of Virus and Maternal/Foetal Immune Mechanisms in Border Disease of Sheep

Border disease (BD) is a congenital disorder of lambs characterized in its typical form by poor viability, low birth weight, tremor, and in smooth-coated breeds by an unusually coarse, hairy, birth-coat. The typical form of BD virus infection, which results in the hairy-shaker lamb, may be regarded as a tolerant condition as the individual is persistently infected but does not produce either a humoral or a cellular immune response. In the alternative form of pathology (AP), which results in gross intracranial malformations, this tolerant state either does not develop or is broken at an early stage, the fetus responding with a necrotizing and mononuclear cell inflammatory reaction in the granuloprival layers of the developing central nervous system (CNS). Antiviral antibody is produced and infection appears to be eliminated before birth. Prominent among the factors that give rise to this altered response is the involvement of heterologous poor-fit antibody in the experimental system and it is clear that the virus is processed in some way, in vitro , or in the maternal host. Though the ovine placenta is impermeable to circulating maternal antibody, even when damaged in the typical form of BD, it is not unreasonable to speculate that virus, complexed with poor-fit antibody, might cross to the fetus, changing the usual pattern of infection and stimulating a response in the fetal host.

Border disease of sheep: isolation of the virus in tissue culture and experimental reproduction of the disease

Border disease of sheep: isolation of the virus in tissue culture and experimental reproduction of the disease

Histological and histocheinical studies of fetal skin follicles in Border disease of sheep

The structure of the epidermis and dermis, and the distribution of reticulin, glycogen, lipid and sulphydryl groups in the skin have been examined in control and Border disease affected sheep fetuses at 95 and 115 days' gestation. In Border disease, there was a temporary retardation of development of the epidermis and skin follicles at 95 days. There was no difference in the structure of the dermis between control and experimental fetuses at either age. No evidence was found to suggest that the keratogenous process was abnormal in Border disease, but the sulphydryl zone of the primary fibres of affected fetuses was situated nearer the skin surface than in control fetuses. This may have been a consequence of the larger size of primary follices in Border disease. Glycogen present in the undifferentiated epidermis of both groups at 95 days' gestation was absent from the stratified squamous epithelium of the 115 days's fetuses. Glycogen and lipid droplets were present in the outer root sheath of primary follicles of all fetuses examined, but their significance is unknown.

Border Disease of Sheep. Comparison of the Results of Serological Testing using Complement Fixation, Immunodiffusion, Neutralization and Immunofluorescent Techniques

SUMMARY Immunodiffusion, complement fixing, and neutralizing antibodies were demonstrated in the sera of sheep and goats and of their progeny after inoculation during pregnancy with tissues from cases of Border disease. Overall there was good agreement between the different tests used on the sera, suggesting that they were measuring related antibodies. Bovine virus diarrhoea virus was used for neutralization tests, bovine virus diarrhoea antigens for immunodiffusion and complement fixation tests, and swine fever virus for the demonstration of neutralization by immunofluorescence. Antibodies were also detected in sera obtained from affected sheep flocks.