Screening of Babesia microti Proteomic Microarrays With Acute and Convalescent Serum of Patients Reveals Novel Targets of Early IgM and IgG Antibodies.

Babesia microti is the cause of a potentially fatal emerging parasitic infection transmitted by ticks. Rapid bedside diagnostic tests are urgently needed. To identify antigens that are targeted by early immune responses, we enrolled 30 patients with confirmed B. microti infection. We used 9 acute, 8 convalescent, and 9 uninfected control sera to screen proteome microarrays of B. microti. We identified 17 antigens that were recognized by IgM and/or IgG antibodies. Twelve of these antigens had not been reported previously. Our approach suggests that there are many antigens that could be used as the basis of rapid bedside diagnostic tests.