ABSTRACT
AbstractBackground: To study the prevention and control strategies of coronavirus disease 2019 (COVID-19), and to analyze the infection of the home-quarantined individuals with epidemic histories (came from Hubei and any other affected regions), but without symptoms in the three incubations after Wuhan closure in Shenzhen.Methods: The sample size was 2,004 individuals based on multistage sampling during the pre-investigation. Based on the results of the pre-investigation, the formal investigation expanded the sample size to 57,012 individuals. A single throat swab was collected from each individual for nucleic acid testing (NAT) by reverse transcription-polymerase chain reaction (RT-PCR). NAT was performed by a third-party institution, BGI. We collected information related to demographics, disease history, travel history, and personal protective measures before home quarantine, and monitored close-contact histories using the We Chat questionnaire.Results: The total infection rate of home-quarantined individuals was 0.11% (95% CI: 0.05%–0.24%) out of the total sample size of 59,016. The detection period for seven confirmed cases was primarily concentrated between February 8 and 18, 2020, which was during the second incubation period after Wuhan's closure. The home quarantined individuals with epidemic histories (came from Hubei and any other affected regions) were considered the high risk population during the first two incubations after Wuhan’s closure. No positive cases were detected from February 25 to present (the third incubation after Wuhan’s closure). The number of newly-confirmed cases per day was 0 for 8 days from February 22 to 29 in Shenzhen. Thus, the strategies of prevention and control were effective.Conclusions: The strategies and policies were effective for the prevention and control of COVID-19. Additionally, the strategy of implementing NAT during the first two incubations for home-quarantined individuals with epidemic histories (came from Hubei and any other affected regions), but without symptoms, facilitated early detection, early reporting, early diagnosis, early quarantining, and early treatment. However, our findings do not support NAT for home quarantined persons during the third incubation after Wuhan’s closure to present.