[1] Univ Washington, Virol Res Clin, Dept Med, Seattle, WA 98122 USA
[2] Univ Washington, Dept Biostat, Seattle, WA 98195 USA
[3] Univ Washington, Dept Epidemiol, Seattle, WA 98195 USA
[4] Univ Washington, Dept Pathol, Seattle, WA 98195 USA
[5] Washington Univ, Dept Lab Med, Seattle, WA USA
[6] Fred Hutchinson Canc Res Ctr, Div Infect Dis, Seattle, WA 98104 USA
[7] Polyclin, Seattle, WA USA