A new report from the Centers for Disease Control and Prevention (CDC) says airport screening programs for arriving passengers did not help catch coronavirus cases, as the International Civil Aviation Organization (ICAO) updates its pandemic guidance for the aviation industry.
The objectives of the screening program were to reduce the importation of COVID-19 cases into the United States and slow subsequent spread within states. Screening aimed to identify travelers with COVID-19–like illness or who had a known exposure to a person with COVID-19 and separate them from others. During January 17–September 13, 2020, a total of 766,044 travelers were screened.
Ineffective and resource-intensive
But CDC’s study found that the temperature and symptom-based screening programs used at U.S. airports were ineffective as well as resource-intensive. Just one laboratory confirmed case per 85,000 travelers screened was identified. In addition, contact information was missing for a substantial proportion of screened travelers in the absence of manual data collection.
The screening program consisted of three steps. First, U.S. Customs and Border Protection officers identified and referred travelers for screening if they had been in one of the specified countries during the previous 14 days. Next, initial screening was conducted, which included observation for signs of illness, a temperature check using a noncontact infrared thermometer, administration of a questionnaire about signs and symptoms (fever, cough, and difficulty breathing) in the preceding 24 hours or exposure to a person with COVID-19 in the preceding 14 days, and collection of travelers’ U.S. contact information. The third step included referral of ill travelers and those disclosing an exposure for additional public health assessment by an on-site medical officer; if indicated, travelers were sent to a local health care facility for medical evaluation. The threshold for sending symptomatic travelers for public health assessment and deciding which among those would be sent for medical evaluation varied during the evaluation period, reflecting evolution of CDC’s definition for “person under investigation” and operational considerations such as testing capacity.
Among the 278 persons who had COVID-19–like symptoms, the most common signs or symptoms triggering assessment were cough (73%), self-reported fever (41%), measured fever (17%), and difficulty breathing (13%). Forty (14%) of these travelers were medically evaluated at a local health care facility, and 35 (13%) were tested for SARS-CoV-2 using reverse transcription–polymerase chain reaction (RT-PCR); nine of the 35 tests returned positive results.
Fourteen additional travelers with laboratory-confirmed COVID-19 were identified through other mechanisms rather than as a direct result of entry screening: six via established processes with airlines and airport partners to detect ill travelers and notify CDC and eight through notifications about travelers who had received a positive test result in the United States or another country before travel.
CDC also found issues with data collection. CDC relied initially on existing federal traveler databases to obtain passenger contact information to share with states, but missing or inaccurate data prompted adding manual data collection to the screening process. Manual data collection resulted in 98.1% complete records (i.e., records contained both phone number and physical address).
Lessons learned
It is worth remembering that the program was an early response to an unprecedented situation. Nevertheless, it highlights a need for a fundamental change in U.S. border health strategy.
Since the screening program ended on September 14, 2020, efforts to reduce COVID-19 importation have focused on enhancing communications with travelers to promote recommended preventive measures, reinforcing mechanisms to refer overtly ill travelers to CDC, and enhancing public health response capacity at ports of entry. Many individual operators are offering their own programs for travelers, such as rapid testing, but a nationwide approach, and even mandates, much earlier in the game, could have greatly reduced the number of cases – and deaths – across the United States while still keeping people and infrastructure moving.
In comparison to the U.S., some Asian countries have been credited with responding well to the pandemic. In many cases, this was a case of acting on lessons learned from previous pandemics such as Taiwan’s 2003 SARS outbreak.
Many countries have adopted ICAO’s “Take-off” guidelines for international air transport, compiled by experts that make up the Aviation Recovery Task Force and building on lessons learned as well as responding to science as more and more becomes known about this coronavirus.
On November 9, ICAO announced the latest revision to these guidelines, which focus on the evolving technological and medical advancements in the fight against COVID-19. They incorporate the continuous feedback ICAO is receiving from national authorities, regional and international organizations, and industry.
Technology aids recovery
The first edition of the Take-off guidelines document noted that rapid COVID-19 tests available at the time were not recommended due to their relatively low level of efficacy. Since then, testing technology has improved and health authorities have gained a greater understanding of how the COVID-19 virus is transmitted and how the effective use of certain tests might contribute to reducing the likelihood of COVID-19 transmission.
Such testing could reduce reliance on measures such as quarantines that restrict movement and cripple industry. Consequently, it has been implemented by some countries and ICAO has tasked the Collaborative Arrangement for the Prevention and Management of Public Health Events in Civil Aviation (CAPSCA) to study available testing methods and advise CART on what factors countries could consider regarding testing, as well as guidance on how to implement testing as part of an overall risk management strategy should they wish to do so.
The Aviation Recovery Task Force now therefore recommends that countries contemplating testing should apply the approach outlined in the ICAO Manual on Testing and Cross Border Risk Management Measures, due for publication on November 16.
CAPSCA has also developed a generic decision-making tool which can be used to determine the inherent and residual risk level of transporting potentially infectious passengers.
Safe restart
The updated guidance includes a new section on general hygiene to be followed at airports and on-board aircraft. It also recommends the use of Public Health Corridors when two or more countries agree to recognize the public health mitigation measures each has implemented on one or more routes between their nations. ICAO has urged the full cooperation and information sharing to ensure these corridors are as successful as possible, and will produce further guidance on this in the coming days.
The Task Force is also mindful of restarting aviation safely in a post-pandemic era. A large proportion of the global fleet, air crew, airport operations staff, and air traffic controllers that have been inactive for prolonged periods will need to be reactivated and retrained, where appropriate.
ICAO reminds countries which have filed differences for temporary departures from ICAO Standards under the COVID-19 Contingency Related Differences (CCRD), or that have granted other COVID-19-related regulatory alleviation, that these differences and alleviations were intended to be temporary in nature. Prolonged differences and alleviations, such as those related to personnel certification and licensing, could result in an elevated operational safety risk. The organization says countries should, therefore, put in place the necessary measures to manage those risks and should not extend alleviations (both core and extended CCRDs) beyond March 31 2021.
While CDC found the early screening program was not effective, it is hoped that this, and future administrations, will use this as a valuable lesson learned. The evolving ICAO guidance has shown how countries, organizations and industry must think and act on the fly to respond to new information and changing risk patterns. Not everyone is going to get it right every time, which is why recognizing failure and adapting quickly is absolutely vital. COVID-19 will not be the last global health disaster we will see in our ever more connected world. As well as confronting this one, all countries must also ensure they are better prepared next time around.
