As in prior studies, RSA59-infected mice showed meningitis, encephalitis, myelitis, and concurrent axonal loss and demyelination as early as day 5 pi with an increase at day 30, whereas RSMHV2 showed only meningitis, encephalitis, and myelitis with no significant demyelination or axonal loss (data not shown) (2) . The livers of both strains showed moderate to severe hepatitis (data not shown), thereby confirming virulence.