1. Edward P. Fitts Department of Industrial and Systems EngineeringNorth Carolina State University Raleigh NC U.S.A.
2. Durham County Department of Public Health Durham NC U.S.A.
3. Gillings School of Global Public Health, University of North Carolina at Chapel Hill Chapel Hill NC U.S.A.
4. Division of Public Health, North Carolina Department of Health and Human ServicesCommunicable Disease Branch, Epidemiology Section Raleigh NC U.S.A.