1. Guangxi Key Laboratory of AIDS Prevention and Treatment, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
2. Guangxi-ASEAN Collaborative Innovation Center for Major Disease Prevention and Treatment, Life Sciences Institute, Guangxi Medical University, Nanning, Guangxi, China
3. Nursing College, Guangxi Medical University, Nanning, Guangxi, China
4. Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
5. Division of Infectious Diseases and International Health, Duke University, Durham, North Carolina, USA