Serendipitous Finding of Asymptomatic Babesiosis in a Patient With Symptomatic Thrombocytopenia

We report a case of isolated immune thrombocytopenic purpura (ITP) as a result of babesiosis infection. The patient initially presented with a history, physical exam and laboratory findings consistent with idiopathic thrombocytopenic purpura. She was treated with standard of care therapy without clinical response. Daily evaluation of the peripheral smear ultimately revealed a red blood cell inclusion, identified and confirmed as a low-titer babesiosis infection indicative of past exposure. As described below, isolated thrombocytopenia related to babesiosis infection has not been reported prior to the patient’s presentation. There are a few cases reported to show a relationship between babesiosis and autoimmune hemolytic anemia without an understood pathophysiologic mechanism. We review the literature, propose a possible pathophysiologic mechanism of disease and consider the implications of swift identification to prevent clinical deterioration.