1. Department of Toxicology Henan Center for Disease Control and Prevention Zhengzhou China
2. Department of Histology and Embryology, School of Basic Medical Sciences Zhengzhou University Zhengzhou China
3. Department of Epidemiology, College of Public Health Zhengzhou University Zhengzhou China
4. Department of Infectious Diseases The Fifth Affiliated Hospital of Zhengzhou University Zhengzhou China