[Prevention of toxoplasmosis in immunocompromised patients]

The main underlying immunosuppressive conditions requiring prevention of toxoplasmosis are organ transplantations (especially heart and bone marrow transplants) and advanced HIV infection (CD4 + lymphocytes count < 100/mm3). Preventive strategies consist in reducing the rate of primary infection, mainly through hygiene and diet measures, and introducing chemoprophylaxis in patients already contaminated by the parasite: the most precise knowledge in this field concerns HIV infected patients. For prevention of recurrence, patients should receive pyrimethamine-sulfadiazine, or otherwise pyrimethamine-clindamycin combinations. For primary prophylaxis, cotrimoxazole is the first-line therapy. If patients cannot tolerate cotrimoxazole, a regiment including dapsone plus pyrimethamine is a possible alternative; pyrimethamine alone and atovaquone are currently under investigation.