Babesiosis developed in a 62-year-old immunocompetent physician, who had an uneventful recovery after receiving atovaquone and azithromycin. Three years later, babesiosis developed again, and he was again successfully given treatment. Clinical and laboratory evidence were highly supportive of Babesia reinfection. Healthcare professionals should be aware that reinfection might occur in babesiosis.
Keywords: Babesia microti; United States; antimicrobial drugs; babesiosis; human babesiosis; immunity; parasites; piroplasm; recurrence; reinfection; tick-borne infections; vector-borne infections.