1. Department of Population and Public Health Science, University of Southern California , Los Angeles, California , USA
2. Research Unit, Foundation for Professional Development , East London , South Africa
3. Department of Medical Microbiology, University of Pretoria , Pretoria , South Africa
4. Division of Medical Microbiology, University of Cape Town , Cape Town , South Africa
5. Graduate School for Cellular and Biomedical Sciences, University of Bern , Bern , Switzerland
6. Division of Infectious Diseases, University of Alabama at Birmingham , Birmingham, Alabama , USA
7. Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center , New Orleans, Louisiana , USA
8. Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania , USA