Study population and setting
On January 17, 2020, the United States Centers for Disease Control (CDC) implemented passenger screening at designated airports for travelers arriving by air from Wuhan, China. Enhanced traveler screening for COVID-19, which involved elicitation of travelers’ potential exposures and illness symptoms, was expanded to inbound travelers from areas with sustained, widespread COVID-19 transmission, including mainland China (February 2); Iran (March 2); Schengen areas of Europe, the United Kingdom, and Ireland (March 14 to 17); and Brazil (May 27). After screening, passengers’ information was forwarded to local health departments at their respective travel destinations. Passengers presenting with signs and symptoms of COVID-19 were isolated and referred to local health facilities for further assessment, including COVID-19 testing when available. The authors assessed performance of the screening program by describing the volume of travelers screened and the proportion of COVID-19 cases identified through enhanced screening at U.S. ports of entry.
Summary of Main Findings
Of the 766,044 travelers screened at 15 designated airports between January 1 and September 13, 2020 (the date traveler monitoring was suspended), 298 travelers (0.04%) were referred for follow-up assessment due to self-reported exposures or symptoms of COVID-19 infection. Forty symptomatic travelers were assessed at local health facilities, 35 of whom received COVID-19 testing by RT-PCR. Nine COVID-19 cases were identified of the 35 travelers tested, yielding a case identification ratio of 1 per 85,000 travelers screened. Fourteen additional COVID-19 cases were identified through other non-screening mechanisms, including diagnosis after travel to the United States or retroactive notification of positive test results prior to travel. Passenger information was forwarded to health departments for roughly 68% of screened travelers.
The authors calculate the number of COVID-19 cases identified as a fraction of total travelers screened at designed U.S. airports from January 17 to September 13, 2020.
Given the 14-day incubation period for COVID-19, passenger screening was likely to miss pre-symptomatic or asymptomatic cases; the true number of COVID-19 infections in screened passengers was, therefore, likely underestimated. As the authors aim to evaluate the airport-based screening program’s performance, inclusion of other performance metrics, like health workforce capacity (i.e., ratio of screening personnel to screened travelers), could have helped contextualize the reported findings.
This study is the first to evaluate the performance of the CDC’s traveler monitoring program for COVID-19 at designated U.S. ports of entry.
This review was posted on: 3 January 2021