Pathogenicity and pathology of Jos virus infection in mice and tissue culture

Jos virus was pathogenic to suckling mice infected by intracerebral (i.c.), intraperitoneal (i.p.), subcutaneous (s.c.), and oral (per os) routes. However, consistent fatality was only obtained in adult mice infected intracerebrally. Suckling mice inoculated by the i.c. route developed viraemia within 24 h post infection, and virions were rapidly disseminated into all visceral organs. High infectivity titres found in organs such as liver and lung as compared to blood indicated that virus multiplication took place in them. Pathological studies in infected suckling mice showed acute cell necrosis in the liver, lymph nodes, bone marrow and spleen. Other organs, including the brain, were unaffected. Secondary cell culture did not readily support growth of the virus and there was no evidence of cytopathic effect or virus multiplication in Vero and BHK-21 cell culture after three passages.