Isolation and Characterization of Whitewater Arroyo Virus, a Novel North American Arenavirus

Rodents are principal hosts for each of the well-characterized arenaviruses. Prior to the present study, Tamiami (TAM) virus was the sole arenavirus known to be indigenous to North America; it has been isolated only from southern Florida where its primary host is the cotton ratSigmodon hispidus.Recently, arenavirus antibody was found inNeotoma albigulawoodrats collected from the southwestern United States. The purpose of the present study was to isolate and characterize the arenavirus associated withN. albigula.Three isolates of a novel arenavirus (proposed name “Whitewater Arroyo,” WWA) were recovered from two arenavirus antibody-positiveN. albigulacollected from Whitewater Arroyo in McKinley County, New Mexico. Two-way serologic tests indicated that WWA virus is antigenically distinct from other arenaviruses but most closely related to TAM virus. Phylogenetic analysis of nucleocapsid protein gene sequence data showed that WWA virus is a novel arenavirus that is genetically most closely related to TAM virus. The recovery of WWA virus from antibody-positiveN. albigulasuggests that WWA virus infection in this species can be chronic and thus thatN. albigulais a reservoir host of the virus.