Arenavirus infection in the guinea pig model: Antiviral therapy with recombinant interferon-α, the immunomodulator CL246, 738 and ribavirin

Human arenaviral infections have a high mortality, and are dangerous to work with in the laboratory. There is a need for good antiviral agents to treat these infections. Pichinde virus infection of the inbred strain 13 guinea pig is a relatively safe, good animal model for human arenavirus infections. Mortality is consistently 100% between days 12 and 25 (mean 14.8) days after infection. When infected animals were treated with recombinant human interferon αA, or with CL246,783, an immunomodulator known to induce interferon, no beneficial effect was noted. When animals received ribavirin, 25 mg/kg/day for the first 14 days of infection, the course of infection was prolonged, with death occurring a mean of 22.5 days after infection. If ribavirin was administered for 28 days, mortality was reduced to 25%, with those animals dying a mean of 21.0 days after infection. These results confirm the studies that indicate that ribavirin is a useful agent for treating arenaviral infections. However, treatment with this agent must be prolonged. They also demonstrate the potential usefulness of Pichinde virus infection in strain 13 guinea pigs as an animal model of human disease.