[1] Vanderbilt Univ, Sch Med, Dept Prevent Med, Nashville, TN 37232 USA
[2] Ctr Dis Control & Prevent, Epidem Intelligence Serv, Epidemiol Program Off, Atlanta, GA USA
[3] Tennessee Dept hlth, Communicable & Environm Dis Serv, Nashville, TN USA
[4] Knox Cty Hlth Dept, Knoxville, TN USA