1. Emory University Rollins School of Public Health, Atlanta, Georgia
2. Emory University Rollins School of Public Health, Atlanta, Georgia, Emory University School of Medicine, Atlanta, Georgia, USA
3. Environment and Health Research Unit, South African Medical Research Council, Johannesburg
4. National Institute for Communicable Diseases, Johannesburg, University of Pretoria, Pretoria, South Africa
5. Albert Einstein College of Medicine, Bronx, New York
6. Columbia University Mailman School of Public Health, New York, New York, USA
7. National Health Laboratory Service, Durban, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
8. National Health Laboratory Service, Durban
9. Emory University Rollins School of Public Health, Atlanta, Georgia, Centers for Disease Control and Prevention, Atlanta, Georgia, USA