Development of Blood Donor Screening for Babesiosis

Human Babesiosis is primarily caused by Babesia microti an intraerythrocytic parasite with some cases on the US west coast associated with Babesia duncani (WA-1). Typically tick bites are the route of transmission. However, both organisms have been associated with transfusion related infections and deaths in immunocompromized recipients. All indications are that the number of cases is on the rise and endemic regions might be expanding both in the US and Europe. Current diagnosis relies on blood smear, lmmunofluorescence (IFA), PCR and confirmation with Western blot. To date there is no FDA approved test for screening the blood supply but the FDA indicated the need for regional screening of blood supplies in July 201 O. Previously we have reported on a Babesia microti specific peptide ELISA that was able to detect a significant number of blood donor sera positive by IFA or western blot. The goal of this proposal is to identify additional immunodominant epitopes from a panel of proprietary recombinant proteins for B. microti (and later 8. duncani) previously selected using serological expression cloning. In addition, bioinformatics will be used to identify immunodominant tandem repeat sequences. These potential antigens will then be used in development of a sensitive ELISA and also potentially provide reagents for use on other blood testing instrumentation. To achieve these goals we have assembled a group of experts in recombinant protein design, ensured access to Babesia microti samples, recombinants and testing of prototypes at the Red Cross