1. Southeast University, Nanjing, Jiangsu Province, China
2. Yixing Center for Disease Control and Prevention, Yixing, Jiangsu Province, China
3. Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu Province, China
4. Colorado State University, Fort Collins, CO, USA
5. The Ohio State University College of Medicine, Columbus, OH, USA