1 Desmond Tutu HIV Centre, Institute of Infectious Disease & Molecular Medicine Department of Medicine, University of Cape Town.
2 Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York Public Health Research Institute Tuberculosis Center, New Jersey Medical School-Rutgers, State University of New Jersey, Newark.
3 Division of Medical Microbiology, University of Stellenbosch National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa.