Serological and virological evidence of a Hantaan virus-related enzootic in the United States. 
The first isolation of a Hantaan-related virus from a feral rat in the United States was made from a Rattus norvegicus caught in New Orleans.  The strain, designated Tchoupitoulas virus, is antigenically related to, but distinct from, the prototype strain 76-118 of Hantaan virus and is the first Hantaan-like virus isolated from the pancreas of a naturally infected animal.  Serosurveys of wild rodents from urban and rural areas in the United States indicated that Hantaan-related viruses infected urban rats in coastal and inland cities and infected five species of New World rodents in the western United States (Peromyscus maniculatus, Peromyscus difficilis, Peromyscus californicus, Neotoma mexicana, and Neotoma cinerea).  Serosurveys disclosed no evidence of Hantaan-virus infection in rats in large-scale breeding colonies.