First documented case of imported human babesiosis in Honduras: Diagnostic challenges with malaria falciparum.

Human babesiosis is an emerging zoonosis that can mimic Plasmodium falciparum malaria, often leading to misdiagnosis in malaria-endemic regions. We report the first confirmed case of imported babesiosis in Honduras. A 72-year-old man returned from Massachusetts and developed fever, neurological symptoms, and ischemic stroke. Thick smears suggested P. falciparum; he was treated with chloroquine-primaquine followed by artemether-lumefantrine, but hyperparasitemia persisted and he developed multiorgan failure, dying on day 33. Molecular assays were negative for Plasmodium but polymerase chain reaction confirmed Babesia 18S rRNA. Retrospective smear review identified the Maltese cross. This fatal case illustrates the diagnostic challenge of distinguishing babesiosis from malaria and underscores the need to consider babesiosis in febrile travelers unresponsive to antimalarials. Strengthening molecular diagnostic capacity is essential in malaria-endemic regions.