About the Authors
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
Shandong Center for Disease Control and Prevention, Jinan, China
College of Public Health, The Ohio State University, Columbus, Ohio, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: LQF XJW SL WCC. Analyzed the data: LQF XJW SL YLL SXS WYZ QQ YPL LW ZQW HY WCC. Contributed reagents/materials/analysis tools: LQF XJW YLL SXS WYZ QQ YPL LW ZQW HY. Wrote the paper: LQF XJW SL WCC.