Experimentelle Herpesvirus SA 8 ? Encephalitis bei Kenia-Pavianen (Papio cynocephalus)

Abstract

Herpesvirus SA 8 infections are occurring naturally in African green monkeys and baboons. Neither the clinical nor the morphological sequelae of SA 8 infections in homologous or heterologous hosts are sufficiently known. Therefore, colony-born baboons of three age groups were inoculated intravenously or intratracheally, using a SA 8 strain (strain 0430) isolated from fatally infected newborn baboons. Of all experimental animals, 63% developed focal encephalitis, characterized predominantly by glial nodule formation and necrosis of nerve and glial cells. Early stages of the infection (2–5 days after infection) were accompanied by inclusion body formation or by eosinophilic nerve cell degeneration. The distribution of the CNS lesions depended largely on the inoculation route. In intravenously inoculated newborn baboons, the inflammatory foci were scattered throughout the entire brain and spinal cord, including the leptomeninges, whereas these lesions were focused on the vagal root areas within the medulla oblongata in the intratracheally inoculated animals of all age groups. In the intratracheally infected animals corresponding herpetic lesions were also commonly found in pulmonary ganglia or pulmonary vagal branches. The possible vagal ascendance of herpesvirus SA 8 from the primarily affected lung to the brain in intratracheally inoculated animals is discussed.