Efficacy of Rapid Treatment Initiation Following Primary Toxoplasma gondii Infection During Pregnancy

Background. Treatment of Toxoplasma gondii infection acquired during pregnancy differs in many countries. In Germany, spiramycin is given until the 16th week of pregnancy, followed by at least 4 weeks of combination therapy with pyrimethamine, sulfadiazine, and folinic acid independent of the infection stage of the fetus. If infection of the fetus is confirmed by polymerase chain reaction or if fetal ultrasound indicates severe symptoms (hydrocephalus, ventricular dilation), treatment is continued until delivery with regular monitoring of pyrimethamine and sulfadiazine concentration in maternal blood and observation of possible adverse effects. In other European countries, such as France, only spiramycin is given unless infection of the fetus is proven. Methods. To evaluate the effectiveness of the German treatment scheme, a retrospective analysis of 685 women who showed a serological constellation consistent with primary infection in pregnancy and their children was performed. Results. We found an increased transmission rate to the fetus with increased time in gestation and a decreased risk of clinical manifestations. In comparison with studies performed in other countries, the overall transmission rate (4.8%) and the rate of clinical manifestations in newborns (1.6%) were lower. Conclusions. Use of spiramycin from time of diagnosis of acute acquisition of infection by the pregnant woman until week 16, followed by pyrimethamine, sulfadiazine, and folinic acid for at least 4 weeks in combination with a standardized follow-up program is efficient in reducing transplacental transmission of the parasite and the burden of disease in the newborn.