Relapsed Babesia microti Infection following Allogeneic Hematopoietic Cell Transplantation in a Patient with B-Cell Acute Lymphoblastic Leukemia: Case Report and Review of the Literature

A patient with relapsed/refractory B-cell acute lymphoblastic leukemia developed babesiosis prior to allogeneic hematopoietic cell transplantation while on atovaquone for Pneumocystis jirovecii pneumonia prophylaxis. Despite receiving a prolonged course of atovaquone and azithromycin until whole blood Babesia microti DNA was no longer detected by polymerase chain reaction, her post-transplant course was complicated by relapsed babesiosis. We investigate the potential host and parasite characteristics causing relapsing/persistent infection.