We investigated 32 families of persons with acute toxoplasmosis in which > or = 1 other family member was tested for Toxoplasma gondii infection; 18 (56%) families had > or = 1 additional family member with acute infection. Family members of persons with acute toxoplasmosis should be screened for infection, especially pregnant women and immunocompromised persons.
Keywords: Toxoplasma; Toxoplasma gondii; United States; acute Toxoplasma infection; acute toxoplasmosis; families; parasites; protozoa; toxoplasmosis.