Characterization of tula virus from common voles (Microtus arvalis) in Poland: Evidence for geographic-specific phylogenetic clustering

Tula virus (TULV), a recently identified arvicolid rodent-borne hantavirus, is harbored by the European common vole (Microtus arvalis) in Central Russia and the Czech and Slovak Republics. We report the isolation and characterization of this hantavirus from M. arvalis captured in Poland, a country where human disease caused by hantaviruses has not been recognized. Of 34 arvicolid rodents (24 Clethrionomys glareolus, 9 M. arvalis, 1 Pitymys sp.) captured in Lodz and Tuszyn, Poland, during June to September 1995, sera from 3 M. arvalis and 3 C. glareolus contained IgG antibodies to Puumala virus (PUUV), as determined by an indirect immunofluorescent antibody assay. Alignment and comparison of the 1852-nucleotide S segment and a 1676-nucleotide region of the G2 glycoprotein-encoding M segment, amplified from lung tissues of two hantavirus-seropositive M. arvalis, revealed 83.9-85.2% and 82.3-83.5% sequence similarity, respectively, with TULV strains from Central Russia and the Czech and Slovak Republics. A > 98% sequence conservation was found at the amino acid level. Phylogenetic analysis indicated that the newly found TULV strains from Poland were closely related to, but distinct from, TULV from elsewhere in Europe.