About the Authors

Hongjie Liu

hliu1210@umd.edu

Affiliation Department of Epidemiology and Biostatistics, School of Public Health, University of Maryland, College Park, Maryland, United States of America

Yongfang Xu

Affiliation Nanning Center for Disease Control and Prevention, Nanning, Guangxi, China

Xinjin Lin

Affiliation Nanning Center for Disease Control and Prevention, Nanning, Guangxi, China

Jian Shi

Affiliation Nanning Center for Disease Control and Prevention, Nanning, Guangxi, China

Shiyi Chen

Affiliation Nanning Center for Disease Control and Prevention, Nanning, Guangxi, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: HL. Performed the experiments: YX XL JS SC. Analyzed the data: HL YX. Contributed reagents/materials/analysis tools: XY JS SC. Wrote the paper: HL XY XL.