Work

Detection and whole-genome characterisation of Regana virus in the bicoloured shrew (Crocidura leucodon) from Graubünden, Switzerland

Year: 2026

Type: article

Abstract: BACKGROUND: Orthonairoviruses are of medical and veterinary importance, but the genetic diversity and geographic distribution of shrew-associated orthonairoviruses remain unclear. Shrews are increasingly recognised as hosts for diverse orthonairoviruses, including Regana virus (REGV), which has been reported in the bicoloured white-toothed shrew (Crocidura leucodon) in Germany and the Czech Republic. METHODS: We examined archived shrew specimens collected in Graubünden Canton, Switzerland, between 2005 and 2006 using nested reverse transcription-polymerase chain reaction, metagenomic next-generation sequencing, phylogenetic analysis, pairwise sequence comparison, and protein feature annotation. RESULTS: Nairoviral RNA was detected in three C. leucodon from Luzein and Malans, whereas four Sorex araneus and one Neomys anomalus tested negative. Complete or near-complete REGV genome sequences were recovered from the three positive animals. Swiss REGV variants clustered with REGV from Germany and the Czech Republic across the S, M, and L segments. RdRp amino acid identities were 98.8-98.9% among Swiss variants and 92.1-95.6% between REGV Np12 and German or Czech variants. Comparative protein analyses identified conserved viral ovarian tumour protease catalytic residues, similar glycoprotein precursor organisations, and nairovirus-like nucleoprotein motifs. CONCLUSIONS: These findings document REGV in C. leucodon in Switzerland and expand the known geographical and genetic ranges of REGV in European shrew populations.

Source: Tropical Medicine and Health

DOI: 10.1186/s41182-026-01108-0