Text and Data Mining valid from 2018-06-19
Received: 25 July 2017
Accepted: 29 May 2018
First Online: 19 June 2018
Ethics and consent to participate
: The ethics approval of this study has been assigned by the Institutional Review Boards at Oxford University and the China National Center for Disease Control. Data used in this study is openly available. All who participated the study provided informed consent.
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