A 14+7 day quarantine period and a dual nucleic acid testing reagent strategy detect potentially indiscoverable Coronavirus disease 2019 infections in Xiamen, China.

"Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper."

"This work was supported by the National Natural Science Foundation of China [grant numbers 82172331, 81972028, 81973104, 81772260, 81672094], the Key Projects for Province Science and Technology Program of Fujian Province, China [grant number 2020D017, 2019D008] and the Natural Science Foundation of Fujian Province, China [grant number 2021J02055] The funders played no role in the study design, data collection, or analyses, the decision to publish, or manuscript preparation. Yong-Jing Wang: Conceptualization, Investigation, Methodology, Formal analysis, Writing – original draft. Jian-Hang Xue: Conceptualization, Investigation, Methodology, Formal analysis, Writing – original draft. Zan-Xi Fang: Methodology, Data curation. Jia-Wen Xie: Methodology, Data curation. Jian-Jun Niu: Funding acquisition, Investigation, Methodology, Project administration, Writing – review & editing. Tian-Ci Yang: Funding acquisition, Investigation, Methodology, Project administration, Writing – review & editing. Li-Rong Lin: Funding acquisition, Investigation, Methodology, Project administration, Writing – review & editing."