Norbert Ndjeka1, Nazir A Ismail2. 1. DR-TB Directorate, National Department of Health, Pretoria, South Africa. Electronic address: norbert.ndjeka@health.gov.za. 2. Centre for Tuberculosis, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa; Department of Medical Microbiology, University of Pretoria, Pretoria, South Africa; Department of Internal Medicine, University of Witwatersrand, Johannesburg, South Africa.