1. Li Li, Li-Jung Liang, Chunqing Lin, Chiao-Wen Lan, and Sung-Jae Lee are with the Semel Institute for Neuroscience and Human Behavior, Center for Community Health, University of California, Los Angeles. Nguyen Tran Hien, Nguyen Anh Tuan, Le Anh Tuan, Duong Cong Thanh, and Nguyen Thi Thanh Ha are with the HIV/AIDS Department, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.