In central Europe, hemorrhagic fevers with renal syndrome (HFRS) in humans are caused by the hantavirus species Puumala (transmitted by voles) and a second, Hantaan-related species (transmitted by mice). The second virus could be identified as Dobrava virus. To date, 19 clinical cases of Dobrava infection have been found in Germany and Slovakia. All patients exhibited a mild/moderate clinical course and no case fatality occurred. Screening for infected rodents revealed that the striped field mouse (Apodemus agrarius) represents the main reservoir for Dobrava virus in central Europe. Nucleotide sequence comparisons and phylogenetic analysis based on complete and partial genomic S segment nucleotide sequences placed the Slovakian A. agrarius-derived hantavirus strains within the Dobrava species, forming a cluster on the Dobrava phylogenetic tree. In east Slovakia, a single Dobrava virus-infected yellow-necked mouse (Apodemus flavicollis) was trapped in a locality that predominantly showed Dobrava-infected A. agrarius. Comparison of the S segment sequence (nucleotides 381-935) revealed that the Dobrava strain from A. flavicollis shows only 84.3% nucleotide homology to A. agrarius-derived strains from this location but 96.3% homology to A. flavicollis-derived Dobrava strains from the Balkans (southeast Europe). Phylogenetic analysis of the partial S segment placed the A. flavicollis-derived Dobrava strain from Slovakia on a distinct Dobrava lineage (DOB-Af) together with the south-east European A. flavicollis-derived strains. The results indicate that Dobrava strains from A. agrarius (DOB-Aa) vs. A. flavicollis (DOB-Af) could develop different degrees of virulence in humans.
Copyright 2001 Wiley-Liss, Inc.