1. At the time of this work, Rebecca L. Weintraub, Kate Miller, Julie Rosenberg, Shreyas Srinath, Samuel R. Woodbury, and Iman Ahmad were with Ariadne Labs, Boston, MA. Benjamin Rader, Marinanicole D. Schultheiss, Molly E. Chiang, and John S. Brownstein were with Computational Epidemiology Lab, Boston Children’s Hospital, Boston. Mansi Kansal, Swapnil Vispute, Stylianos Serghiou, Gerardo Flores, Akim Kumok, Tomer Shekel, and Evgeniy Gabrilovich were with Google Inc, Mountain View, CA.