ABSTRACT
Almost uniform protection against congenital toxoplasmosis initiated by inoculations with cysts and oocysts of the parasite was seen in the hamster model, among strains of different genotypes. Because the RH immunization prior to pregnancy has to be controlled with medication for most of the hamsters to survive, and also some congenital transmission of Toxoplasma was observed during the chronic stage of the infection, the hamster is considered less practical than the rat and the BALB/c mouse models. It is concluded that the hamster model closely resembles protection against congenital infection in nature, where most of the pregnant women and ewes that experienced a toxoplasma infection previously, protect their fetuses against an infection with the parasite during pregnancy.
Subject(s)
Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Complications, Parasitic/parasitology , Protozoan Vaccines/immunology , Toxoplasma/immunology , Toxoplasmosis, Animal/congenital , Toxoplasmosis, Animal/transmission , Toxoplasmosis, Congenital/transmission , Animals , Biological Assay , Cricetinae , Disease Models, Animal , Female , Humans , Mesocricetus , Pregnancy , Pregnancy Complications, Parasitic/prevention & control , Sheep , Toxoplasma/classification , Toxoplasmosis, Animal/prevention & control , Toxoplasmosis, Congenital/prevention & controlABSTRACT
The objective of the research was to test the hamster for a model of transmission of congenital toxoplasmosis. A non-invasive method for the diagnosis of pregnancy in hamsters was designed, with a specificity and a sensitivity of 70.2 and 94.7%, respectively (n=168). Of 32 females with a chronic toxoplasma infection, 3 transmitted Toxoplasma congenitally during their first pregnancy, but not during the subsequent pregnancy. Congenital transmission rates of infections initiated during pregnancy with 2 stages of 2 strains of Toxoplasma were in the range of 33 to 100% of the 76 females inoculated. Only 1 of 17 females transmitted the parasite exclusively via milk. It was concluded that the hamster is a promising species for a model of transmission of congenital toxoplasmosis.
