A New Frontier

Discovery of phylogenetically divergent hantaviruses in shrews and moles (order Soricomorpha, family Soricidae and Talpidae) raises the possibility that rodents (order Rodentia, family Muridae and Cricetidae) may not be the principal or primordial reservoirs. Moreover, newfound hantaviruses harbored by soricomorphs of multiple species, distributed in widely separated geographic regions across four continents, suggest that their host diversity may be far more expansive than previously assumed. Specifically, other mammals having shared ancestry or ecosystems with soricomorphs may serve as reservoirs and may be important in the evolutionary history and diversification of hantaviruses. In particular, bats (order Chiroptera) may be potential reservoirs by virtue of their rich biodiversity and vast geographical range, as well as their demonstrated ability to host myriad medically important, disease-causing viruses. A multi-national team, led by Richard Yanagihara, has detected hantavirus RNA in ethanol-fixed liver tissue from the banana pipistrelle (Neoromicia nanus), in Cote d’Ivoire, West Africa. Phylogenetic analysis of partial L-segment sequences using maximum-likelihood and Bayesian methods revealed that the newfound hantavirus, designated Mouyassue virus (MOUV), was highly divergent and basal to all other rodent- and soricomorph-borne hantaviruses, except for Nova virus in the European common mole (Talpa europaea). MOUV heralds a new frontier in hantavirus discovery.

A brief communication, reporting the preliminary sequence analysis of MOUV, has earned the distinction of being ‘highly accessed’, with more than 1,000 accessions since its appearance on-line in Virology Journal on January 26, 2012 (http://www.virologyj.com/mostviewed). High throughput sequencing efforts, now underway, will provide further insights into the evolution and diversification of hantaviruses.