Modulation of Bhanja virus infection in mice.

Randombred (ICR) and inbred (C57B1/6) 4-wk-old SPF male mice were infected extraneurally with Bhanja virus (Bunyaviridae) and subjected to various treatments. Immunosuppression with cyclophosphamide (CPA) affected the course of the infection when a higher dose (10(6) suckling mouse intracerebral LD50) of the virus and 2 or 3 injections of CPA (150 mg/kg each) were given: then a part of the animals died due to viral encephalitis, whereas all the CPA-untreated infected mice survived. A dual peripheral infection with Bhanja and Lipovnik (Reoviridae) viruses did not cause any symptomatic response, and the host's humoral antibody was slightly stimulated. When Bhanja virus was given prior to, or simultaneously with, tick-borne encephalitis virus (Flaviviridae), a moderate decrease of the mortality (due to tick-borne encephalitis) occurred. A mixed peripheral infection of mouse with Bhanja virus and Cryptococcus neoformans, did not result in a fatal virus encephalitis of the host, nor was cryptococcosis affected substantially. However, formalin-killed cells of the fungus ("cryptococcin") administered before the extraneural inoculation of Bhanja virus caused an 8-fold increase of antibodies neutralizing the virus; a mild therapeutic or protective effect of cryptococcin on encephalitis after an intracerebral application of Bhanja virus was also observed.