1. Division of Infectious Disease, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
2. Research Unit, Foundation for Professional Development, Pretoria, South Africa
3. Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, USA
4. Department of Epidemiology and Biostatistics, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
5. Anova Health Institute, Johannesburg, South Africa
6. School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
7. Department of Medical Microbiology, School of Public Health and Primary Care, Maastricht University, Maastricht, Netherlands
8. Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa