Babesiosis

Most human cases of babesiosis are due to Babesia microti species complex or to B. divergens, but with increasing recognition of human cases, other species, some of them newly described, have been found to infect humans. Recent years have seen an expansion of human B. microti infection in the Northeastern USA. Dual infection with Borrelia burgdorferi is increasingly seen and even triple infection with babesiosis, Lyme disease, and anaplasmosis is recorded. There have been at least 200 cases of transfusion-transmitted babesiosis in the USA, raising significant concern regarding blood transfusion safety.