ABSTRACT
The present review deals with the similarities and differences of selected aspects of prenatal pestivirus infections of domestic animals and congenital rubella of man. Hog cholera virus, bovine virus diarrhoea virus and border disease virus are antigenically closely related, but unrelated to rubella virus. The nonarbo togaviruses are capable of producing congenital infections resulting in a wide spectrum of abnormalities. The infected foetus can die in utero, in the neonatal period, or it may be born with teratogenic defects. In addition, apparently healthy progeny can be delivered that develop a late onset disease, months, or years after birth, or remain clinically normal for life. The ultimate outcome of a congenital infection is mainly determined by the stage of foetal development, at which infection occurs. Foetuses exposed to rubella virus raise an antibody response to the virus, whereas domestic animals frequently fail to respond immunologically to a congenital pestivirus infection. In congenital rubella the virus usually disappears from the host's body 1-2 years after birth. However, congenital pestivirus infections may be characterized by a lifelong and widespread persistence of virus in clinically healthy animals. Such animals are of significance in the epizootiology of bovine virus diarrhoea, border disease or hog cholera.
Subject(s)
Bovine Virus Diarrhea-Mucosal Disease/congenital , Cattle Diseases/congenital , Classical Swine Fever/congenital , Sheep Diseases/congenital , Togaviridae Infections/veterinary , Abortion, Veterinary/etiology , Animals , Animals, Newborn , Antibodies, Viral/biosynthesis , Cattle , Classical Swine Fever Virus/physiology , Congenital Abnormalities/veterinary , Diarrhea Viruses, Bovine Viral/physiology , Female , Fetal Death/veterinary , Humans , Immune Tolerance , Immunity, Cellular , Maternal-Fetal Exchange , Pestivirus/physiology , Placenta/microbiology , Pregnancy , Rubella/congenital , Sheep , Swine , Togaviridae Infections/congenital , Togaviridae Infections/immunologyABSTRACT
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.
Subject(s)
Abortion, Veterinary/etiology , Sheep Diseases/transmission , Togaviridae Infections/veterinary , Animals , Central Nervous System Diseases/congenital , Central Nervous System Diseases/transmission , Central Nervous System Diseases/veterinary , Female , Pestivirus , Pregnancy , Pregnancy Complications, Infectious/veterinary , Sheep , Sheep Diseases/congenital , Togaviridae Infections/congenital , Togaviridae Infections/transmissionABSTRACT
A flock problem affecting newborn lambs on a Minnesota farm was investigated. The lambs had hairy fleece and rhythmic tremors, and were unthrifty. Histologic examination revealed hypomyelinization of the CNS and hypertrophy of primary follicles in the skin. A virus antigenically related to bovine viral diarrhea virus was isolated. Serum neutralization showed that a large number of flock ewes had much higher titers to bovine viral diarrhea virus than did control animals.