Funding for this research was provided by:
National S & T Major Project Foundation of China (2012ZX10001-001)
Zhejiang Provincial Medicine Science and Technology Plan (2015PYA004)
Social Development Project of Public Welfare Technology Research in Zhejiang Province (LGF18H260006)
‘National S & T Major Project Foundation of China’ (2017ZX10201101002)
Text and Data Mining valid from 2018-04-17
Received: 29 November 2017
Accepted: 12 April 2018
First Online: 17 April 2018
Ethics approval and consent to participate
: This study was approved the Institutional Review Board of the National Center for AIDS/STD Control and Prevention, China CDC (IRB approval number: X120331209). Written informed consent was provided by all participants prior to completion of the survey. All the participants signed the informed consent.
: The authors declare that they have no competing interests.
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