Histopathology and distribution pattern of inflammation in naturally with SBV-infected neonatal ruminants (n = 15) of the central nervous system (HE-staining).

A) Spinal cord of a sheep displaying mild, multifocal lymphohistiocytic infiltrates in meninges, perivascular spaces and the parenchyma of gray and white matter (animal no 4; C = central canal; F = fissura mediana ventralis; bar, 1000 µm). B) Moderate perivascular infiltrates characterized by lymphocytes and macrophages in the brain of a SBV-infected sheep (animal no 10; bar, 20 µm). C) Coronal section of a brain showing the mesencephalon, hippocampus, lateral ventricle as well as parietal and temporal lobes. The temporal lobe of this sheep lamb displays a porencephaly with complete loss of the white matter in the center (asterisk; animal no 5; M = mesencephalon; bar, 5000 µm). D) Topographic map of a coronal brain section displaying parietal, temporal lobes, mesencephalon and hippocampus summarizing the percentages of histologic findings in all investigated animals with respected to specific brain regions. E) Percentages of brain regions displaying inflammatory changes in ruminants with SBV infection. F) Occurrence of CNS malformations in SBV-infected animals associated with (n = 15) and without inflammation (n = 72). Percentages of animals displaying cerebellar hypoplasia (CH), porencephaly (P), hydranencephaly (H), hydrocephalus internus (HI) and no malformations (none) are given. Absolute numbers of affected animals are given on top of the bar. Note, that one animal exhibited more than one malformation.