[1] Johns Hopkins Univ, Dept Biol, Baltimore, MD 21218 USA
[2] Rice Univ, Dept Biosci, Houston, TX 77005 USA
[3] Cornell Univ, Dept Stat & Data Sci, Ithaca, NY 14850 USA
[4] Imperial Coll London, Dept Math, London, England
[5] Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06511 USA
[6] Stanford Univ, Sch Med, Div Primary Care & Populat Hlth, Stanford, CA 94305 USA
[7] Stanford Univ, Sch Med, Div Cardiovasc Med, Stanford, CA 94305 USA
[8] Stanford Univ, Sch Med, Div Infect Dis & Geog Med, Stanford, CA 94305 USA