1. Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, New Haven, CT, USA.
2. Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
3. Department of Biomedical Sciences, Oregon State University, Corvallis, OR, USA.
4. Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA.
5. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.
6. Ministry of Health and Social Welfare, Monrovia, Liberia.