Fatal Babesiosis in an Immunocompetent Patient.

Human babesiosis is an emerging infectious disease with a progressively rising number of cases in the Northeast over the last few decades. We report a case of fatal babesiosis in a 48-year-old male without significant risk factors for a severe presentation. Clinicians should be aware that even in patients without the classic risk factors of asplenia, advanced age, and immunocompromised status for severe presentations of babesiosis, a deadly case can present. There is a need for further research regarding optimal treatment options for severe babesiosis considering the questionable efficacy of red blood cell exchange (RCE) transfusion in patients who do not improve on the current first-line antimicrobials.