Encephalitis in aborted bovine fetuses associated with Bovine herpesvirus 1 infection.
Brain tissue from 12 aborted bovine fetuses submitted to the Wisconsin Veterinary Diagnostic Laboratory revealed histologic lesions that consisted of glial nodules and variable degrees of mononuclear inflammation, microhemorrhage, neuronal necrosis, and cerebral cortical cavitation. A diagnosis of Bovine herpesvirus 1 (BHV-1) abortion had been made in all of these cases through multiple testing modalities. Brain tissue from 8 of the 12 fetuses was immunohistochemically stained with a monoclonal antibody specific to BHV-1, and, in 5 fetuses, there was positive intralesional staining of neurons, glial cells, and endothelial cells. This preliminary data suggested that herpesviral infection of brain tissue led to the described neurologic lesions. BHV-1 was then amplified from brain tissue in all 12 of the fetuses and was confirmed by partial sequencing of the thymidine kinase and glycoprotein C genes. To the authors' knowledge, neurologic lesions have not previously been described in BHV-1-infected fetuses, nor has BHV-1 previously been identified in bovine fetal brain tissue. The neurologic histopathology attributed to BHV-1 infection in these cases overlaps with the neurologic lesions produced by Neospora caninum, a common etiologic agent of bovine abortion. Therefore, when bovine fetal neurologic lesions are found, both etiologies should be considered and then distinguished by using additional diagnostic tools.
Brower
Alexandra
A
Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin, Madison, WI 53706, USA. alexandra.brower@wvdl.wisc.edu
Homb
Kelly M
KM
Bochsler
Philip
P
Porter
Robert
R
Woods
Karen
K
Ubl
Sue
S
Krueger
David
D
Cigel
Francine
F
Toohey-Kurth
Kathy
K
D000034:Abortion, Veterinary / Q000821:virology*; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D004660:Encephalitis / Q000662:veterinary* / Q000821:virology; D005260:Female; D005333:Fetus / Q000473:pathology / Q000821:virology; D005814:Genes, Viral; D006566:Herpesviridae Infections / Q000150:complications*; D007242:Herpesvirus 1, Bovine / Q000235:genetics; D008969:Molecular Sequence Data; D011247:Pregnancy; D012698:Serologic Tests / Q000662:veterinary