1. Division of Clinical Pharmacology, Department of Medicine, Stellenbosch University, Cape Town, South Africa.
2. Department of Medical Microbiology, Stellenbosch University, Cape Town, South Africa.
3. Division of Clinical Haematology, Department of Medicine, Stellenbosch University, Cape Town, South Africa.
4. Clinical Pharmacology Division, Department of Medicine, Stellenbosch University, Cape Town, South Africa.