Immunopathogenesis of toxoplasmosis in pregnancy.

The immunopathogenesis of toxoplasmosis during pregnancy is not completely understood. This paper will try to discuss the most frequently asked questions about the immunopathogeny of congenital toxoplasmosis: differential virulence of Toxoplasma isolates, genetic susceptibility to infection, facilitation of placental transfer, models of congenital toxoplasmosis, and transmission in seropositive hosts. Most published data suggest a role of the genetic background of the host and of the parasite. Models of congenital toxoplasmosis have been evaluated, but it appears that the conclusion drawn would be barely appropriate to understand the pathogenesis in pregnant women.