Transfusion-Acquired Babesiosis and Failure of Antibiotic Treatment

Abstract

HUMAN babesiosis is a zoonosis characterized by fever, malaise, and hemolytic anemia. In the United States, the disease is generally caused by the species Babesia microti , a protozoan parasite of rodents, and is transmitted by Ixodes dammini , the northern deer tick. 1 Most of the 200 known cases of human babesiosis in the United States followed exposure to I dammini on the coastal islands of the Northeast, particularly Nantucket Island, Massachusetts, and Shelter Island, New York. Asymptomatic infections occur frequently 2 and create potential for transmission of infection through blood donation. 3-6 Recently the range of I dammini , which is also the principal vector of Lyme disease, has increased dramatically, with a resulting increase in the incidence of human babesiosis and Lyme disease. 7 Herein we report the first case of babesiosis acquired in New Hampshire and cite evidence indicating that the infection was transfusion acquired. This case also documents