1. Division of Ophthalmology, St John Eye Hospital/Chris Hani Baragwanath Academic Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
2. Centre for Tuberculosis, National TB Reference Laboratory, WHO TB Supranational Laboratory Network, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
3. Department of Molecular Medicine & Haematology, School of Pathology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa
4. Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit (VIDA), Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa