toxoplasmose

Toxoplasmosis is a disease caused by the intracellular protozoan parasite Toxoplasma gondii. It is one of the most common parasitic infections worldwide and can infect most warm-blooded animals, though cats are the definitive hosts. Humans are usually infected through undercooked meat, contaminated soil or water, or in some cases from contaminated milk. Vertical transmission from mother to fetus can occur during acute maternal infection.

Most infections are asymptomatic. When symptoms occur, they resemble a mild flu-like illness with lymphadenopathy. In immunocompromised people, especially with AIDS or after organ transplantation, toxoplasmosis can cause severe disease with encephalitis, seizures, pulmonary or retinochoroidal inflammation. Congenital toxoplasmosis occurs when a mother acquires infection during pregnancy, possibly leading to miscarriage, hydrocephalus, intracranial calcifications, chorioretinitis, or neurodevelopmental problems.

Diagnosis relies on serology (IgG and IgM), visualization or PCR of body fluids; amniotic fluid testing can assess fetal infection. Imaging may show brain lesions in encephalitis.

Treatment depends on disease severity and pregnancy status: acute infection outside pregnancy is treated with pyrimethamine and sulfadiazine plus folinic acid; spiramycin is used during pregnancy to reduce fetal transmission; severe CNS disease or congenital infection is treated with pyrimethamine, sulfadiazine, and folinic acid. Alternatives include clindamycin for sulfa allergy.

Prevention focuses on cooking meat thoroughly, washing fruits and vegetables, avoiding exposure to cat litter, especially during pregnancy, and good hygiene to prevent oocyst ingestion. Seroprevalence varies by region and exposure level.