Viral Persistence and Abnormalities of the Central Nervous System after Congenital Infection of Sheep with Border Disease Virus

Abstract

Lambs congenitally infected with border disease (BD) virus and sheep exposed to BD virus as adults were studied for one year to determine the pathogenesis of congenital exposure compared with adult exposure to the virus. Persistent BD virus was isolated in tissue culture and detected by immunofluorescence of the peripheral white blood cells, urine, and cerebrospinal fluid of lambs with congenital BD up to one year of age. These animals had no detectable serum neutralizing antibody response to the virus for the same interval. BD virus antigen was also detected by immunofluorescence in many central nervous system tissues of these lambs with congenital BD. Dysmyelination and glial proliferation in the central nervous system and microencephaly were noted in the lambs with congenital BD, and these lesions appeared to remain the same over a 12-month period.

Concurrent Peste des Petits Ruminants Virus and Pestivirus Infection in Stillborn Twin Lambs

“…9,17,23,25,27,28 In the stillborn lambs of this report, pathologic, immunohistochemical, and RT-PCR findings corroborated the assumption that these malformations resulted from pestivirus infection.…”

“…11,25 When twin fetuses are infected, BD may differ in severity and type of lesions in each fetus such that one fetus has classical lesions, such as hydranencephaly and hypomyelination, whereas the other fetus has milder white matter cavitation and porencephaly. 12,18,23,25,26 In this study, we report the pathologic, immunohistochemical, and molecular diagnostic features of concurrent PPRV and BDV infection in stillborn twin lambs. A 2.5-year-old ewe in dystocia in the fifth month of pregnancy was presented to the Gynecology and Theriogenology Clinics of the Faculty of Veterinary Medicine, Kirikkale University.…”

Is some white matter damage in preterm neonates induced by a human pestivirus?

“…White matter damage, disturbances of myelination, and subsequent microcephaly follow herpes simplex encephalitis,11 exposure to rubella virus in utero,12 13 14 and canine distemper virus infection 15. Microcephaly, dysmyelination, glial proliferation,16 ventricular enlargement, and extensive necroses in the white matter10 are associated with pestivirus infection. Because these types of damage so closely resemble those of WMD in preterm neonates, we suggest that human pestivirus is a likely mediator of virus induced WMD.…”

Persistence of RNA Viruses in the Central Nervous System

“…Persistent virus can be detected in the blood, urine, and CSF of lambs congenitally infected with this virus more than one year after infection. Hypomyelination and microencepha ly are seen, and virus antigen is found in scattered cells of undefined nature in gray and white matter (84). after intracerebral inoculation of MHV -JHM is normally fatal.…”

“…Both in hog cholera and in border disease virus infection of piglets and lambs, similar hypomyelination occurs. Virus antigen persists in the brain in as yet unidentifkd cells in the white matter (84).…”