1. Department of HIV World Health Organization Geneva Switzerland
2. Centre for Infectious Disease Epidemiology and Research School of Public Health and Family Medicine University of Cape Town Cape Town South Africa
3. Desmond Tutu HIV Centre Institute of Infectious Disease and Molecular Medicine Cape Town South Africa
4. Department of Medicine University of Cape Town Cape Town South Africa
5. Department of Infectious Disease Epidemiology Imperial College London London United Kingdom
6. Government of Zimbabwe Ministry of Health and Child Care, AIDS and TB Unit Harare Zimbabwe