Abstract
The patient was admitted to the hospital and, given the absence of international travel and the reported tick exposure, empiric treatment for presumed babesiosis† was initiated. On August 9, a thin blood smear obtained at the time of admission was reported to show Plasmodium falciparum malaria with 3.2% parasitemia. In accordance with Maryland law, the smear and whole blood specimen were also submitted to the Maryland Department of Health (MDH) public health laboratory. Because the patient had no reported international travel and did have a history of tick exposure, as well as documented clinical improvement (reduction in parasitemia to 0.2%), the patient was discharged on August 10 with instructions to complete a 7-day babesiosis treatment course.§ On August 15, testing at MDH public health laboratory identified P. falciparum using smear microscopy, the BinaxNOW Malaria rapid diagnostic test (Abbott), and 18S rRNA polymerase chain reaction (PCR).