[1] CNA Inst Publ Res IPR, 3003 Washington Blvd, Arlington, VA 22201 USA
[2] Johns Hopkins Univ, Dept Emergency Med, Baltimore, MD USA
[3] Ctr Dis Control & Prevent Cdc, Div Emergency Operat DEO, Ctr Preparedness & Response CPR, Atlanta, GA USA
[4] Ctr Dis Control & Prevent Cdc, Div State & Local Readiness DSLR, Ctr Preparedness & Response CPR, Atlanta, GA USA
[5] Commissioned Corps Us Publ Hlth Serv USPHS, Rockville, MD USA
[6] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Environm Hlth & Engn, Baltimore, MD USA