About the Authors

Yang Yu

Contributed equally to this work with: Yang Yu, Minglei Xu

Affiliation Weihai Center for Disease Control and Prevention, Weihai, Shandong, PR China

Minglei Xu

Contributed equally to this work with: Yang Yu, Minglei Xu

Affiliation Medical College, Qingdao University, Qingdao, Shandong, PR China

Jiandong Sun

Affiliation Queensland University of Technology, Brisbane, Queensland, Australia

Ruiying Li

Affiliation Weihai Center for Disease Control and Prevention, Weihai, Shandong, PR China

Meilan Li

Affiliation Weihai Center for Disease Control and Prevention, Weihai, Shandong, PR China

Jianguang Wang

Affiliation Weihai Center for Disease Control and Prevention, Weihai, Shandong, PR China

Dongfeng Zhang

aqxuepi@163.com (AX); zhangdf1961@126.com (DZ)

Affiliation Medical College, Qingdao University, Qingdao, Shandong, PR China

Aiqiang Xu

aqxuepi@163.com (AX); zhangdf1961@126.com (DZ)

Affiliations Academy of Preventive Medicine, Shandong University, Jinan, Shandong, PR China, Shandong Provincial Key Laboratory of Infectious Disease Control and Prevention, Shandong Center for Disease Control and Prevention, Jinan, Shandong, PR China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: AX DZ. Performed the experiments: YY MX. Analyzed the data: JS. Contributed reagents/materials/analysis tools: RL ML JW. Wrote the paper: YY MX.