1. HIV and Hepatitis Research Unit, Department of Virology, Medunsa Campus, University of Limpopo/National Health Laboratory Service, Pretoria, South Africa.
2. AIDS Virus Research Laboratory, Department of Microbiology, University of Venda, Thohoyandou, South Africa.
3. Institute of Infectious Diseases and Molecular Medicine, Division of Medical Virology, University of Cape Town/National Health Laboratory Service, Cape Town, South Africa.