1. Centers for Disease Control and Prevention, Atlanta, Georgia
2. Department of Medical Microbiology, Africa Centre for Population Studies and Reproductive Health, Medical Research Council Genital Ulcer Disease Research Unit, University of Natal Medical School, Durban, South Africa
3. National Reference Centre for Sexually Transmitted Diseases, Department of Clinical Microbiology and Infectious Diseases, University of Witwatersrand
4. South African Institute of Medical Research, Johannesburg, South Africa