1. Department of Global Health and Infectious Diseases, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
2. Department of Health Behaviour, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
3. Department of Epidemiology, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
4. Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
5. Department of Health Policy and Management, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.