General description

Neonatal toxoplasmosis is a common zoonotic infection caused by Toxoplasma gondii, second only to neonatal CMV infection. It can occur through transplacental infection during a pregnant woman's primary infection, with outcomes ranging from asymptomatic to miscarriage or stillbirth.

T. gondii infection usually occurs through ingestion of undercooked meat contaminated with cysts or ingestion of oocysts from food or water contaminated with cat feces. The rate of fetal infection increases the later in gestation the maternal infection occurs. However, fetuses infected early in gestation tend to develop more severe disease. Overall, congenital infection occurs in a proportion of infants born to women infected during pregnancy. When a pregnant woman is primarily infected with toxoplasma, the parasite can cross the placenta and infect the fetus.

Outcomes of intrauterine infection range from asymptomatic to miscarriage or stillbirth, and even symptomatic infections vary in severity. Neonatal toxoplasmosis is known for the four major signs of hydrocephalus, visual impairment due to chorioretinitis, intracranial calcifications, and psychomotor retardation. Other possible symptoms include lymphadenopathy, liver dysfunction, jaundice, anemia, and thrombocytopenia.

Differential diagnoses

Neonatal CMV infection

Neonatal toxoplasmosis is less likely to cause cortical malformations compared to Cytomegalovirus (CMV) infection (neonatal). However, neonatal toxoplasmosis is associated with a higher incidence of hydrocephalus.