[1] Fred Hutchinson Canc Res Ctr, Epidemiol & Biostat Program, Div Publ Hlth Sci, Seattle, WA 98109 USA
[2] Fred Hutchinson Canc Res Ctr, Program Canc Biol, Div Human Biol, Seattle, WA 98109 USA
[3] Univ Washington, Sch Publ Hlth & Community Med, Dept Biostat, Seattle, WA USA
[4] Univ Washington, Sch Publ Hlth & Community Med, Dept Epidemiol, Seattle, WA USA
[5] Univ Washington, Sch Med, Dept Microbiol, Seattle, WA USA
[6] Univ Washington, Sch Med, Dept Pathol, Seattle, WA USA