Clinical Practice and Cases in Emergency Medicine

Babesiosis, mainly endemic within the Northeastern and upper Midwestern regions of the United States, is a zoonotic disease that invades and lyses red blood cells, which can result in hemolytic anemia. Its decreased incidence in comparison to Lyme disease is often attributed to the greater asymptomatic infection proportion and insufficient physician awareness or suspicion of this disease. Here we describe a case of undifferentiated febrile illness with hemolytic anemia that yielded the diagnosis of babesiosis.