1. School of Public Health, Shandong University, Jinan, China.
2. Huangdao District Center for Disease Control and Prevention, Qingdao City, China.
3. School of Medicine, Fudan University, Shanghai, China.
4. School of Health Sciences, Wuhan University, Wuhan, China.
5. Department of Pathology, University of Texas Medical Branch, Galveston, Texas.