Funding for this research was provided by:
National Natural Science Foundation of China (81700534)
National Science and Technology Major Project (2014ZX10002002)
scientific research plan of Jilin Health and family planning commission (2016G001)
the Jilin Province Science and Technology Development Plan (20160520158JH)
the Program for JLU Science and Technology Innovative Research Team (2017TD-08)
Text and Data Mining valid from 2018-09-03
Received: 4 January 2018
Accepted: 22 August 2018
First Online: 3 September 2018
Ethics approval and consent to participate
: Written informed consent was obtained from each participant or their guardian, if the patient was a minor aged <16 years, prior to enrollment. The present study was reviewed and approved by the Ethics Committee of the Changchun Center for Disease Control and Prevention.
: Not applicable
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.