Funding for this research was provided by:
the National Special Science and Technology Project for Major Infectious Diseases of China (2012ZX10004-220, 2016ZX10004222-006)
the China-UK Global Health Support Programme (GHSP-CS-OP1-01)
The Forth Round of Three-Year Public Health Action Plan of Shanghai, China (15GWZK0101, GWIV-29)
Text and Data Mining valid from 2018-08-17
Received: 19 November 2017
Accepted: 30 July 2018
First Online: 17 August 2018
Ethics approval and consent to participate
: This study was a questionnaire based survey and personal identifiers were coded prior to analysis. Therefore ethical consent was not essential.
: Not applicable.
: The authors declared that they have no competing interests.