Babesia microti, Babesia duncani (WA1) and Babesia sp. (MO1) are obligate intra-erythrocytic protozoans transmitted by tick vectors, causing flu-like symptoms as well as a malaria-like illness. All three agents can be transmitted by blood donor units from asymptomatic donors. Although B. microti is evident throughout the New World, the ranges of WA-1 and MO1 are much less defined, so we will be producing 3-antigen MIF slides to learn more about the distribution of these three pathogens. As these are all propagated in vitro and in-house we have the opportunity to optimize each antigen to make them more specific and remove unwanted characteristics.