Characterization of Congenital Toxoplasmosis in Israel: A 17-year Nationwide Study Experience

Background: Congenital toxoplasmosis (CT) can cause significant neurologic manifestations and other untoward sequelae. Neither the current epidemiology nor the disease severity of CT in Israel is known. Methods: Records of CT were collected from the National Toxoplasmosis Reference Laboratory and from 15 medical centers across Israel between 2001 and 2017. Eligible case-patients were fetuses or infants <12 months of age at the time of diagnosis. Results: Of the 43 CT cases identified, 24 (55%) were in Jews and the remaining 19 cases were in patients of Arab (non-Bedouin) origin. The overall annual estimated rate of symptomatic CT was calculated as 0.55 per 100,000 live births. One or more severe clinical manifestations were reported in 12 (46%) of the 28 live-born infants and included cerebral calcifications (7 cases), chorioretinitis (4 cases), hydrocephalus (2 cases) and 1 case of death. Sensitivities of blood polymerase chain reaction (PCR), cerebrospinal fluid PCR and IgM antibody tests were 50% each. However, analyzing PCR samples from both sites, together with IgM testing, increased the sensitivity to 93%. Conclusions: The relative rate of severe manifestations was higher than in previous European reports. It is possible that the greater disease severity observed in Israel is in part due to the lack of systematic antenatal treatment and screening. Arab (non-Bedouin) infants are at higher risk for contracting CT. Performing serologic and PCR tests simultaneously is essential to improve CT diagnosis. This study demonstrates a need for an educational program to target high-risk populations.