novel outbreak enterovirus D 68 strain associated with acute flaccid myelitis 1 ! cases in the United States from 2012-2014 : a retrospective cohort study 2 ! 3 !

Alexander L. Greninger, M.D., Ph.D., Samia N. Naccache, Ph.D., Kevin 4! Messacar, M.D., Anna Clayton, B.S., M.P.H., Guixia Yu, B.S., Sneha Somasekar, 5! B.S., Scot Federman, B.A., Doug Stryke, B.S., Christopher Anderson, B.S, 6! Shigeo Yagi, Ph.D., Sharon Messenger, Ph.D. , Debra Wadford, Ph.D. , Dongxiang 7! Xia, M.D., Ph.D., James P. Watt, M.D., M.P.H. , Keith Van Haren, M.D., Samuel R. 8! Dominguez, M.D., Ph.D., Carol Glaser, D.V.M., M.D., Grace Aldrovandi, M.D., and 9! Charles Y. Chiu, M.D., Ph.D.* 10! 11! Affiliations: 12! University of California, San Francisco, CA, USA 13! UCSF-Abbott Viral Diagnostics and Discovery Center, San Francisco, CA, USA 14! Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, 15! CO, USA 16! California Department of Public Health, Richmond, CA, USA 17! Lucile Packard Children's Hospital at Stanford University, Palo Alto, CA, USA 18! Children's Hospital Los Angeles and University of Southern California, Los Angeles, 19! CA, USA 20! 21! These authors contributed equally to the manuscript. 22! *corresponding author 23! Charles Chiu 24! Department of Laboratory Medicine 25! University of California, San Francisco, San Francisco, CA 26! charles.chiu@ucsf.edu 27! 28!