Transplacental infection in guinea pigs inoculated with an attenuated strain of Junin virus.

Transplacental infection by the attenuated XJC13 strain of Junin virus (JV) in the guinea pig model was evaluated. 5 pregnant guinea pigs were infected intramuscularly at 45 +/- 3 days of pregnancy. 4 animals were killed at 14 days postinfection (p.i.), and 1 was sacrificed at 137 days p.i. at the end of its second pregnancy. Evidence of JV was obtained by Vero cell cocultivation in all 14 fetuses harvested (brain and/or spleen) and in 10 of 11 placentas. The results strongly suggest that the attenuated JV strain infected the fetus by the transplacental route, as previously demonstrated for the pathogenic XJ strain. Despite limited sampling, the acute as well as the chronic stage proved viable.