[1] Univ Kansas, Med Ctr, Marion Merrell Dow Lab Viral Pathogenesis, Kansas City, KS 66160 USA
[2] Univ Kansas, Med Ctr, Dept Microbiol, Kansas City, KS 66160 USA
[3] Univ Kansas, Med Ctr, Lab Anim Resources, Kansas City, KS 66160 USA
[4] Univ Kansas, Med Ctr, Dept Pathol & Lab Med, Kansas City, KS 66160 USA