Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. mkb6@cdc.gov
Viruses of the Arenaviridae cause hemorrhagic fevers and neurologic disease in humans. Historically, the arenaviruses have been divided into two complexes (LASV-LCMV, Tacaribe) through the use of antigenic typing. The phylogeny of the Arenaviridae as a whole has not been estimated previously due to a lack of sequence data for all members of the family. In this study, nucleocapsid protein gene sequence data were obtained for all currently known arenaviruses and used to estimate, for the first time, a phylogeny of the entire virus family. The LCMV-LASV complex arenaviruses are monophyletic and comprise three distinct lineages. The Tacaribe complex viruses also are monophyletic and occupy three distinct lineages. Comparisons of arenavirus phylogeny with rodent host phylogeny and taxonomic relationships provide several examples in which virus-host cospeciation is potentially occurring. The pathogenic arenaviruses do not appear to be monophyletic, suggesting that the pathogenic phenotype has arisen in multiple independent events during virus evolution.