1. From the Departments of Pediatric Infectious Diseases (R.E.W., M.J.C.), Pediatric Critical Care Medicine (K.S.T., N.S.G.), Pediatric Anesthesiology (G.M.H.), and Pediatric Neurology (C.M.A.-L., M.J.S.), Medical College of Wisconsin, Milwaukee; and the Centers for Disease Control and Prevention, Atlanta (C.E.R.).