Acquired toxoplasmic retinochoroiditis after platelet transfusions.

We present a rare well-documented case of acquired toxoplasmic retinochoroiditis transmitted by platelet transfusion. A 52-year-old woman developed severe thrombocytopenia shortly after receiving a sulfamethoxazole-containing antibiotic. This episode was treated with platelet transfusions and a three-day course of corticosteroids. Thirteen days later, she developed an acute febrile illness typical of the typhus-like form of toxoplasmosis. Fifty-six days later, while still taking corticosteroids for recurrent immune thrombocytopenia, she developed an acute macular retinochoroiditis OD. Serology showed recently acquired toxoplasmosis. Epidemiologic investigation revealed no possible source for the toxoplasmosis other than the platelet transfusion.