1 Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, China.
2 Department of Infectious Diseases, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China.
3 NHC Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China.
4 Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, China, Department of Infectious Diseases, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China.