Isolation and propagation of nephropathia epidemica virus in bank voles

Three strains of nephropathia epidemica (NE) virus were isolated from lung tissues of bank voles (Clethrionomys glareolus) and a grey-sided vole (C. rufocanus) trapped in Västerbotten county, Sweden. Two of these isolates were serially passaged in seronegative laboratory-bred bank voles. Experimentally infected animals developed a subclinical infection characterized by virus persistence, particularly in lung tissue. Attempts to infect other species of colonized rodents with NE virus and to isolate NE virus from acute phase patient blood were unsuccessful. The serial propagation of NE virus in colonized bank voles provides opportunities to study experimental infection in its reservoir rodent host.