About the Authors

Xiaofang Wang

Affiliation National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing, People's Republic of China

Jessie L. Norris

Affiliation National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing, People's Republic of China

Yingjie Liu

Affiliation Institute for AIDS/STD Control and Prevention, Beijing Chaoyang District Center for Disease Control and Prevention, Chaoyang District, Beijing, People's Republic of China

Sten H. Vermund

Affiliation Vanderbilt Institute for Global Health, Departments of Pediatrics and Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America

Han-Zhu Qian

Affiliation Vanderbilt Institute for Global Health, Departments of Pediatrics and Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America

Ling Han

Affiliation Department of Sociology, University of California San Diego, San Diego, California, United States of America

Ning Wang

wangnbj@163.com

Affiliation National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Changping District, Beijing, People's Republic of China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: XW NW. Performed the experiments: XW YL. Analyzed the data: XW SHV HZQ. Contributed reagents/materials/analysis tools: LH. Wrote the paper: XW JLN. Assisted with financial support of the experiments: NW.