Evaluation and Treatment of Fetal Exposure to Toxoplasmosis

Abstract

Symptomatic congenital toxoplasmosis is a rare disease in the United States. However, prenatal screening is becoming increasingly available, resulting in identification of infants at risk of developing the disease. Infants who are born asymptomatic may still develop significant neurodevelopmental sequelae months or even years after birth if untreated. Congenital toxoplasmosis is a difficult infection to diagnose. Using one case as an example, this review attempts to highlight the importance of identifying at-risk infants and summarize the most current recommendations with regard to workup and treatment of affected infants. Initial evaluation of an infant at risk of congenital toxoplasmosis includes complete history and physical examination, lumbar puncture, head computed tomography, complete blood cell count with differential, detailed ophthalmologic examination, and Toxoplasma gondii polymerase chain reaction and serologic testing. Because of the complexity of the laboratory studies involved, expert interpretation is required. Although there is still much to learn about the best approach to the identification and treatment of affected infants, we know that early treatment leads to the best neurodevelopmental outcomes.

The Impact of Maternal Infection on the Neonate

“…Illness can range from non-specific systemic symptoms such as fever, lymphadenopathy and hepatosplenomegaly to congenital toxoplasmosis (CT), which is classically described as a triad of chorioretinitis, intracranial calcifications and hydrocephalus. CT can lead to loss of vision and hearing, decreased cognitive function, and neurodevelopmental delay if untreated [14,[16][17][18].…”

“…gondii exists in three forms: tachyzoite, bradyzoite, and sporozoite. The definitive hosts are members of the Felidae family, but warm-blood mammals can also serve as intermediate hosts [17]. Felines can acquire T. gondii through the ingestion of tissue cysts containing bradyzoites in infected prey or through the ingestion of oocysts containing sporozoites in anything contaminated with feces from an infected cat.…”

“…If a pregnant woman is found to have acute infection, then an amniocentesis can be performed, and the fluid can be sent for polymerase chain reaction (PCR) testing. If the PCR is negative and the fetus is believed to have not acquired the infection, the next best step is treatment in the mother with spiramycin in an attempt to prevent transmission [14,15,17,18]. If, however, the fetus is thought to be infected, then the mother is started on a combination of Congenital Anomalies in Neonates -Clinical Perspectives pyrimethamine, sulfadiazine, and folinic acid.…”

“…Spiramycin, a primarily bacteriostatic macrolide that has activity against some gram-negative and gram-positive organisms as well as some spirochetes, is unable to cross the placenta whereas the combination of anti-parasitic medications can cross the placenta and thus can aide in treatment of the fetus [18,19]. The combination is also used for fetal infection confirmed at or after 18 weeks of gestation or maternal infection acquired during the third trimester [14,17,18]. As untreated CT can lead to fetal demise or death within the first few days of life, and chorioretinitis can develop in a significant proportion of infants whose mothers were untreated, it is imperative to diagnose and start treatment in a timely manner [18].…”

Congenital toxoplasmosis the overlooked disease: a case report

“…Nevertheless, they may still develop significant neurodevelopmental sequelae and chorioretinitis months or even years after birth if are left untreated. 3 Studies have demonstrated that screening and treatment for toxoplasmosis during pregnancy can help to decrease the vertical transmission and the clinical sequelae thereafter. 4…”