1. Medical Division, Translational Research Department South African National Blood Service Roodepoort South Africa
2. Division of Clinical Haematology, Department of Medicine, Faculty of Health Sciences University of Cape Town Cape Town South Africa
3. Division of Clinical Haematology University of the Free State Bloemfontein South Africa
4. Operations Testing Department, Operations Division South African National Blood Service Roodepoort South Africa
5. Departments of Laboratory Medicine and Epidemiology/Biostatistics University of California, San Francisco San Francisco California USA
6. Vitalant Research Institute San Francisco California USA
7. Division of Clinical Pharmacology, Department of Medicine University of Cape Town Cape Town South Africa