Epidemiological study on toxoplasmosis in pregnancy: effectiveness of the screening

Toxoplasmosis is a zoonoses caused by the protozoan Toxoplasma gondii. Human infection, due to ingestion of the parasite oocysts, usually asymptomatic or associated with non specific symptoms (fever, malaise, lymphadenopathy), during pregnancy may cause serious health problems to the fetus, such as mental retardation, seizures, blindness, and death. The classic triad of signs suggestive of congenital toxoplasmosis includes chorioretinitis, hydrocephalus, and intracranial calcifications. In recent years it has been questioned if universal screening for and treatment of acute toxoplasmosis during pregnancy may have a role in reducing and/ or preventing vertical transmission of the infection. A ten-year (2000-2009) prospective epidemiological study was conducted to evaluate the benefits of such screening in terms of reduction of perinatal morbidity and mortality by toxoplasma infection. Of 10,336 women, who underwent prenatal screening (except 10 patients) and delivered during this decade at the same city hospital in Catania, 25 patients (2.42%) were found to be affected by toxoplasmosis and started one of two designated medical treatment, depending upon the gestational age at the time of supposed onset of the infection. Only 2 case (one of them from a non-screened mother) of congenital toxoplasmosis, in a subclinical form, out of 10,362 live births (0,2%) were detected in the study population. The incidence of maternal and congenital toxoplasmosis found in this study is similar with that reported in most of the Western Countries. However, the rate of congenital infection is at the lowest level, especially if compared with that of Countries where the screening is not recommended, suggesting that this is related to the prompt identification of all maternal seroconversions and their subsequent treatment. The results of this study seem support the efficacy of the screening test, whose cost has been quantified is equal to about 42 Euro per live birth, in contrasting the perinatal morbidity by toxoplasma infection. Other studies are necessary to confirm this conclusion.