Document is current

Article History

Received: 21 May 2018

Accepted: 27 December 2018

First Online: 5 January 2019

Ethics approval and consent to participate

: Because this study constituted public health surveillance rather than research in human beings, ethical approval from institutional review boards was waived by the ethic committee of Dandong International Travel Healthcare Center. Data collected from participants in this study are required by WHO’s International Health Regulations and the Frontier Health and Quarantine Law of China, consent to participate was not needed [CitationRef removed, CitationRef removed].

: 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.