Primary and secondary changes in the brains of suckling Balb/c mice with experimental hemorrhagic fever

To testify whether primary changes caused by the virus with its related factors and secondary changes caused by hypotension in the brains of patient with epidemic hemorrhagic fever (EHF) could be repeated in the animal model, suckling Balb/c mice were inoculated IP with 100 LD50/0.05 ml of Chen strain of hemorrhagic fever virus. After the onset of the disease, paraformaldehyde and glutaraldehyde were used for fixation by perfusion through left ventricle. Sections stained with HE and MAb against EHF virus by immunocytochemical method (4-step PAP) showed diffuse viral antigen deposition. All brains were diffusely scattered with single cell acidophilic necrosis which are believed to be caused primarily by the virus. 33.3% of the brains also showed symmetrical distribution of cerebral infarct-like necrosis which are believed to be caused secondarily by hypotension. This result supports our previous study on the autopsy of brains of EHF patients.