1 Division of Global HIV and TB, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA. Electronic address: plp3@cdc.gov.
2 Departments of Global Health, Medicine, and Epidemiology, University of Washington, Seattle, WA, USA.
3 Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.