[1] Univ Delaware, Coll Hlth Sci, Epidemiol, 100 Discovery Blvd, Newark, DE 19713 USA
[2] Ctr Dis Control & Prevent, Off Appl Res, Ctr Preparedness & Response, Atlanta, GA USA
[3] RTI Int, Ctr Commun Sci, Durham, NC USA
[4] Avar Consulting, Rockville, MD USA
[5] Ctr Dis Control & Prevent, US Publ Hlth Serv, Ctr Preparedness & Response, Div State & Local Readiness, Atlanta, GA USA