1. Montefiore Medical Center & Albert Einstein College of Medicine, Bronx, New York, USA
2. University of Pennsylvania, Philadelphia, Pennsylvania, USA
3. Yale University School of Medicine, New Haven, Connecticut, USA
4. University of Colorado, Denver, Colorado, USA
5. Philanjalo, Tugela Ferry, South Africa
6. Umzinyathi District Department of Health, Dundee, South Africa
7. Health Systems Research Unit, Medical Research Council, Cape Town, South Africa; and Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
8. KwaZulu-Natal Department of Health, Pietermartizburg, South Africa
9. Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa