桃園國際機場實施 COVID-19 入境普篩之成效分析

Abstract

背景及目的 COVID-19大流行期間，各國相繼實施邊境管制措施以防止病毒跨境傳播，我國於2021年7月實施入境普篩政策以強化邊境檢疫效能，惟此政策對陽性個案檢出效果之量化評估仍待深入探討。本研究旨在分析自桃園國際機場入境且於21天內確診COVID-19之個案資料，評估普篩政策對早期發現入境確診個案之成效，比較政策實施前後於確診時程及人口學特徵之差異，並辨識影響早期檢出之關鍵風險因子，為邊境檢疫政策制定提供實證依據。

方法 本回溯性研究納入2020年3月至2021年12月期間自桃園國際機場入境旅客為研究對象，以2021年7月實施入境普篩政策為界，分為入境普篩前及入境普篩後兩組，探討實施入境普篩政策對COVID-19 確診時間與陽性率之影響及人口學特徵之差異。分別對所有入境旅客進行卡方檢定比較陽性率差異，對確診者進行Kaplan-Meier存活分析評估確診日數差異，並以Cox比例模型進行風險因子之分析。

結果 本研究區間共920,258人次自桃園國際機場入境，其中1,851例個案於入境後21日內確診 COVID-19。對所有入境旅客進行卡方檢定，普篩前陽性個案發現率為0.0253%，入境普篩後為0.1965%，差異具統計顯著性 (χ² = 737.32, p < 0.001)。進一步對陽性者進行 Kaplan-Meier 存活分析，顯示入境普篩後個案確診時間明顯縮短，中位確診日由入境第8天提前至入境第2天。多變項 Cox 比例風險分析顯示，在調整症狀狀態、國籍等變項後，入境普篩後個案相較於入境普篩前，其被檢出之速率提升126% (aHR = 2.26, 95% CI: 2.03–2.52, p < 0.001)，顯示普篩政策有助於快速辨識潛在感染者，加速診斷與隔離。其他顯著影響因子包含入境時自主申報有症狀 (aHR = 2.26, 95% CI: 1.95–2.63, p < 0.001) 及非本國籍 (aHR = 0.49, 95% CI: 0.44–0.55, p < 0.001)。

結論 本研究證實實施入境普篩政策能有效縮短確診時間並提升陽性個案檢出率，為邊境檢疫政策制定提供實證依據。研究結果顯示，普篩政策不僅加速確診個案之檢出，更顯著增加自覺無症狀感染者的檢出比例，有效提升邊境檢疫的監測效率。基於不同啟程地區之風險評估結果，建議未來可針對高風險來源地實施加強檢疫措施。本分析結果可為調整邊境管制策略提供重要參考，並為未來新興疫情之邊境措施規劃奠定實證基礎。

Background and Objectives During the COVID-19 pandemic, countries worldwide implemented border control measures to prevent cross-border viral transmission. Taiwan implemented universal entry testing in July 2021 to enhance border quarantine effectiveness. However, quantitative evaluation of this policy's impact on positive case detection remains to be thoroughly investigated. This study aims to analyze data from cases entering through Taoyuan International Airport and confirmed with COVID-19 within 21 days, evaluate the effectiveness of universal entry testing policy on early detection of confirmed entry cases, compare differences in diagnosis timeline and demographic characteristics before and after policy implementation, and identify key risk factors affecting early detection to provide evidence-based support for border quarantine policy formulation.

Methods This retrospective study included travelers entering through Taoyuan International Airport from March 2020 to December 2021. Using the implementation of universal entry testing policy in July 2021 as the cutoff, participants were divided into pre-testing and post-testing groups to explore the impact of universal entry testing policy on COVID-19 diagnosis time, positive rates, and demographic characteristics. Chi-square tests were performed on all entry travelers to compare differences in positive rates, Kaplan-Meier survival analysis was conducted on confirmed cases to evaluate differences in days to diagnosis, and Cox proportional hazards models were used for risk factor analysis.

Results During the study period, 920,258 person-times entered through Taoyuan International Airport, with 1,851 cases confirmed with COVID-19 within 21 days after entry. Chi-square testing of all entry travelers showed that the positive case detection rate increased significantly from 0.0253% in the pre-screening period to 0.1965% in the post-screening period, with statistically significant differences (χ² = 737.32, p < 0.001). Further Kaplan-Meier survival analysis of positive cases showed that the time to diagnosis after entry was significantly shortened in the post-screening period, with median diagnosis day advancing from day 8 to day 2 after entry. Multivariate Cox proportional hazards analysis showed that after adjusting for symptom status, nationality, and other variables, post-screening cases had a 126% increase in detection rate compared to pre-screening cases (aHR = 2.26, 95% CI: 2.03–2.52, p < 0.001), indicating that screening policy helps rapidly identify potential infected individuals and accelerate diagnosis and isolation. Other significant influencing factors included self-reported symptoms at entry (aHR = 2.26, 95% CI: 1.95–2.63, p < 0.001) and non-Taiwanese nationality (aHR = 0.49, 95% CI: 0.44–0.55, p < 0.001).

Conclusions This study confirms that implementing universal entry testing policy can effectively shorten diagnosis time and improve positive case detection rates, providing evidence-based support for border quarantine policy formulation. Results show that testing policy not only accelerates detection of confirmed cases but also significantly increases the detection proportion of self-perceived asymptomatic infected individuals, effectively improving border quarantine surveillance efficiency. Based on risk assessment results from different departure regions, enhanced quarantine measures for high-risk source areas are recommended for future implementation. These analytical results can provide important references for adjusting border control strategies and establish an evidence-based foundation for planning border measures against future emerging epidemics.