Human babesiosis in Germany: Just overlooked or truly new?

Tick-borne infections are among the more important vector-borne infections in the northern hemisphere. However, many facts pertaining to the epidemiology and pathogenesis of such diseases in Europe remain unclear. Human babesiosis in particular may have previously been overlooked in many parts of the world due to a lack of medical awareness and microbiological detection methods. Recently, the first two cases of human babesiosis were reported in Germany, occurring in vicinities where the presence of Babesia spp. in enzootic cycles was obvious for decades but where the risk of acquiring Babesia spp. either from ticks or from human blood products was not known before. It is important to note, though, that as with other tick-borne diseases, Babesia infections may arise in geographic areas where they have not been recorded in the past. Better molecular detection methods and strain typing of parasites are necessary to investigate the epidemiological distribution of zoonotic Babesia spp. in Europe and to clarify whether their virulence or transmissibility is strain-dependent. Therefore, further seroepidemiological and molecular epidemiological studies are urgently needed to learn more about the distribution and medical relevance of these pathogens in various parts of Europe in general and in Germany in particular.