Risk assessment of transfusion-associated babesiosis in Tyrol: appraisal by seroepidemiology and polymerase chain reaction

Authors


  • The study was supported by the European Union (Interreg IV), the Tyrol (Austria), and the Autonomous Province of Bozen/South Tyrol (Italy).

Abstract

Background

After malaria, babesiosis is the second most common transfusion-transmitted parasitic disease in the United States. In Europe, one reported transfusion case, concerning Babesia microti, occurred in Germany.

Study Design and Methods

Due to the fact that Babesia spp. are present in Tyrolean ticks, the aim of this study is to assess the occurrence of immunoglobulin (Ig)G antibodies against the Babesia divergens complex, including B. divergens and Babesia venatorum (EU1), as well as B. microti by screening a representative collective of 988 blood donors from North and East Tyrol (Austria) with indirect immunofluorescence antibody test. Additionally, we investigated 206 local ixodid ticks for the presence of babesial DNA by polymerase chain reaction.

Results

Seroprevalence data resulted in rates of 2.1% for IgG antibodies against the B. divergens complex and 0.6% against B. microti in Tyrolean blood donors. All sera could be confirmed by independent retesting. Our data indicate that cross-reactivity is high between B. divergens and B. venatorum and lower than 19.8% between B. divergens and B. microti.

Conclusions

This study shows that Babesia spp. are present in the Tyrols, which blood donors come into serologic contact with, and that we have to consider how to sustain blood product safety concerning this new challenge. Additionally, it is the first description of B. venatorum in the Tyrols, found in one Ixodes ricinus at the Italian border.

Ancillary