1. Biology Division, School of Natural and Applied Sciences, Faculty of Science and Sport, University of Technology, Kingston, Jamaica.
2. Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
3. University of North Carolina Center for AIDS Research and Department of Microbiology and Immunology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
4. Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina.
5. Department of Community Health and Psychiatry, University of the West Indies, Mona, Kingston, Jamaica.