1. Rollins School of Public Health, Emory University, Atlanta, GA, USA, and the Medical Research Council/ National Institute for Communicable Diseases/University of the Witwatersrand Respiratory and Meningeal Pathogens Research Unit, Johannesburg, South Africa.
2. former Department of Medical Microbiology, South African Institute for Medical Research, Johannesburg
3. National Tuberculosis Reference Laboratory, National Institute for Communicable Diseases and Division of Virology and Communicable Diseases Surveillance, University of the Witwatersrand, Johannesburg