Duvenhage Virus: Morphological, Biochemical, Histopathological and Antigenic Relationships to the Rabies Serogroup

SUMMARY Duvenhage virus was originally isolated in South Africa from the brain of a man who had been bitten by a bat and died after a rabies-like illness. Previous immunofluorescence tests indicated that the virus was distinct from rabies virus. In the present study an antigenic relationship of this virus to rabies is defined, and pathological, morphological and further serological characterization is presented. Duvenhage virus-infected mice developed a central nervous system disease characterized by a short incubation period, a moderate degree of inflammatory infiltration of brain parenchyma and by small intraneuronal inclusion bodies. By electron microscopy typical rhabdovirus particles were found budding upon endoplasmic reticulum and plasma membranes of brain neurons. In these characteristics Duvenhage virus resembled laboratory or ‘fixed’ strains of rabies virus. The structural polypeptide composition of Duvenhage virus was very similar to that of rabies virus. Duvenhage virus could be distinguished from rabies by in vivo neutralization and cross-challenge tests in mice, and to a lesser extent by complement-fixation and fluorescent antibody tests. Antibody to purified ribonucleoproteins used in indirect immunofluorescence tests did not distinguish between rabies and Duvenhage virus. In vitro neutralization tests using antisera against whole virus, and against purified virus glycoprotein, confirmed the distinction; consequently Duvenhage virus should be considered a new member of the rabies serogroup (i.e. Lyssavirus genus, Rhabdoviridae family).