PRENATAL-DIAGNOSIS AND TREATMENT OF CONGENITAL TOXOPLASMA-GONDII INFECTIONS - AN EXPERIMENTAL-STUDY IN RHESUS-MONKEYS

The efficacy of treatment in fetuses in whom congenital Toxoplasma gon dii infection had been established has been investigated using rhesus monkeys as a model for humans. A polymerase chain reaction has been de veloped for the detection of Toxoplasma gondii. Using this polymerase chain reaction congenital infection can be established within 2 days o f receiving an amniotic fluid sample. The polymerase chain reaction ha s subsequently been used to monitor the effect of treatment on fetal i nfection. The results show that early treatment with the combination o f pyrimethamine and sulfadiazine was clearly effective in reducing the number of parasites in the infected fetus. The parasite was no longer detectable in the amniotic fluid 10 to 13 days after treatment was st arted. Spiramycin, on the other hand, has to be administered for at le ast 3 weeks to achieve the same effect. Moreover, pharmacokinetic stud ies revealed that spiramycin does not reach the brain. Pyrimethamine a nd sulfadiazine are able to pass the blood-brain barrier. Pyrimethamin e appears to accumulate in the brain tissue and reaches concentrations which are also effective in vitro. (C) 1997 Elsevier Science Ireland Ltd.