Phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) and dusky shrew (Sorex monticolus) in the United States

Abstract

A limited search for hantaviruses in lung and liver tissues of Sorex shrews (family Soricidae, subfamily Soricinae) revealed phylogenetically distinct hantaviruses in the masked shrew (Sorex cinereus) from Minnesota and in the dusky shrew (Sorex monticolus) from New Mexico and Colorado. The discovery of these shrew-borne hantaviruses, named Ash River virus and Jemez Springs virus, respectively, challenges the long-held dogma that rodents are the sole reservoir hosts and forces a re-examination of their co-evolutionary history. Also, studies now underway are aimed at clarifying the epizootiology and pathogenicity of these new members of the genus Hantavirus.

FIGURE 1

Maximum-likelihood phylogenetic consensus trees, generated by Bayesian Metropolis–Hastings Markov Chain Monte Carlo (MCMC) tree-sampling methods using a GTR+I+G model of evolution partitioned by codon position, based on the alignment of the partial 1048-nucleotide S- and 347-nucleotide L-genomic segments of Jemez Springs virus (JMSV MSB89332, EF619960, EF619962) from the dusky shrew (Sorex monticolus) and Ash River virus (ARRV MSB73418, EF619961, EF650086) from the masked shrew (Sorex cinereus), as well as representative murinae rodent-borne hantaviruses, including Hantaan virus (HTNV 76-118, NC_005219, NC_005222), Sangassou virus (SANV SA14, DQ268651, DQ268652), Dobrava virus (DOBV Greece, NC_005234, NC_005235), and Seoul virus (SEOV 80 39, NC_005237, NC_005238); arvicolinae rodent-borne hantaviruses, including Tula virus (TULV M5302v, NC_005228, NC_005226), Prospect Hill virus (PHV PH-1, X55128, EF646763) and Puumala virus (PUUV Sotkamo, NC_005223, NC_005225); and sigmodontinae and neotominae rodent-borne hantaviruses, including Andes virus (ANDV Chile 9717869, NC_003467, NC_003468) and Sin Nombre virus (SNV NMH10, NC_005215, NC_005217). Cao Bang virus (CBNV TC-3, EF543524, EF543525) from the Chinese mole shrew (Anourosorex squamipes), Tanganya virus (TGNV Tan826, EF050454, EF050455) from the Therese shrew (Crocidura theresae), and Thottapalayam virus (TPMV VRC-66412, AY526097, EU001330) from the Asian house shrew (Suncus murinus) are also shown. Numbers at each node are posterior node probabilities based on 30,000 trees: two replicate MCMC runs consisting of four chains of 2 million generations each sampled every 100 generations with a burn-in of 5000 (25%). Sufficiency of chain length was determined based on convergence of likelihood values, giving effective sample sizes well over 400 (implemented in MrBayes v. 3). The scale bar indicates 0.1 nucleotide substitutions per site. Alternate phylogenetic methods gave rise to essentially identical topologies, with only minor, unsupported differences. Host identifications of S. monticolus and S. cinereus were confirmed by mitochondrial DNA sequencing (data not shown).