Final answer:
The classic triad of congenital toxoplasmosis includes chorioretinitis, hydrocephalus, and intracranial calcifications, resulting from fetal infection by Toxoplasma gondii during pregnancy.
Step-by-step explanation:
The classic triad of congenital toxoplasmosis consists of chorioretinitis, hydrocephalus, and intracranial calcifications. This condition is a result of the fetus being infected with the parasite Toxoplasma gondii during pregnancy. If a pregnant woman becomes newly infected with T. gondii, she can transmit the parasite to the fetus, leading to these distinct clinical presentations. The diagnosis of congenital toxoplasmosis can be challenging, and typically requires a combination of clinical findings, serological tests, and imaging studies. It is also important to note that not all infants infected with toxoplasmosis will have all three components of the triad, and symptoms can vary in severity. To prevent congenital toxoplasmosis, pregnant women are advised to avoid undercooked meat and contact with cat feces, which are common sources of T. gondii infection.