1. Department of Infectious Diseases, Lanzhou Pulmonary Hospital, Lanzhou, China.
2. Institute for STD and AIDS Prevention and Control, Lanzhou Center for Disease Control and Prevention, Lanzhou, China.
3. Department of Internal Medicine, Gansu Province Hospital Rehabilitation Center, Lanzhou, China.
4. Department of Infectious Diseases, Gansu Province Hospital Rehabilitation Center, Lanzhou, China.