Funding for this research was provided by:
National Major Science and Technology Projects of China (2014ZX10003002, 2015ZX10003003)
China CDC Balance funds project (2013ZX10003-004)
Received: 25 October 2019
Accepted: 31 December 2019
First Online: 7 January 2020
Ethics approval and consent to participate
: Ethics approval of this study was waived by the Ethical Committees of the Chinese Center for Disease Control and Prevention. The 2007 national drug resistance survey was approved by the Tuberculosis Research Ethics Review Committee of the Chinese Center for Disease Control and Prevention and written informed consent was obtained from each participant.
: Not applicable.
: The authors declare that they have no competing interests.