A Case of Human Babesiosis Confirmed by Polymerase Chain Reaction and Treated with Atovaquone and Azithromycin

ABSTRACT

Human babesiosis is a tick-borne infectious disease caused by Babesia species. The clinical diagnosis is difficult because of nonspecific symptoms like flu. Rapid diagnosis of human babesiosis is microscopic examination in peripheral blood smear (Giemsa-stain) which reveals characteristic forms of an intracellular quadruplet parasite. But differentiation between Babesia microti and Plasmodium species can be quite difficult because of the morphologic similarity. We experienced a case of human babesiosis. The patient was a 62-year old Korean male who had been in New Jersey, U.S.A for 2 months. We initially diagnosed as malaria infection because the peripheral blood smear revealed intracellular single ring form organism. But the patient was not improved significantly by the treatment with chloroquine regimen. Finally we confirmed human babesiosis by polymerase chain reaction for Babesia microti. We treated the patient successfully with a regimen of atovaquone and azithromycin which has fewer adverse reactions than a regimen of clindamycin and quinine.