[Transmission and course of parasitemia of Babesia microti (Hannover I strain) in the bank vole (Clethrionomys glareolus) and field vole (Microtus agrestis)].

In Germany only M. agrestis has been found to be naturally infected with B. microti while in other European countries several rodent species were found as mammalian hosts. In the laboratory C. glareolus got easily infected by German strains of B. microti, if parasitized blood was inoculated. But results of this method are not transferable to natural conditions. Therefore this study was carried out. It was to prove whether C. glareolus is susceptible to B. microti transmitted by nymphs of I. ricinus, or not. To compare the results, M. agrestis was infected in the same way. Both of them proved to be susceptible. The parasitaemia lasted for months. In the beginning the rate of parasitaemia reached 2%, then decreased below 0.1%. The course of infection was variable. In blood smears B. microti could not be detected at all times, so that in field trials the infection rate in mice will often be underestimated. A connection between parasitaemia and gravidity or lactation was not observed under laboratory conditions.