1. State Key Laboratory of Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), Chinese Center for Disease Control and Prevention (China CDC), Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing, China.
2. Third Hospital of Baotou City, Baotou, China.
3. Liangshan Prefecture Center for Disease Control and Prevention, Xichang, China.
4. Sichuan Provincial Center for Disease Control and Prevention, Chengdu, China.
5. Xichang Center for Disease Control and Prevention, Xichang, China.
6. Department of Education and Training, Chinese Center for Disease Control and Prevention, Beijing, China.