1 Ministry of Health and Social Welfare, 1000 Monrovia 10, Liberia; University of Liberia, Monrovia, Liberia. Electronic address: mfallah1969@gmail.com.
2 Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, New Haven, CT, USA.
3 The International Rescue Committee, New York, NY, USA.
4 University of Liberia, Monrovia, Liberia; Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, New Haven, CT, USA.