SARS-CoV-2 molecular diagnosis at airports to minimize travel-related COVID-19 spread

Abstract

Following the identification of SARS-CoV-2, screening for air travel helped mitigate spread, yet lessons learned from a case study of air travel within Canada display enhanced techniques to better identify infected individuals, informing future responsive screening. While international travel bans limit infectious spread beyond a country's borders, such measures are hardly sustainable economically and infrequently address domestic travel. Here, we describe a case study from Canada, where a diagnostic laboratory at point of travel conducted real-time PCR-based detection of SARS-CoV-2 in support of existing interventions, including clinical and epidemiological questionnaires, and temperature checks. All mining workers departing from a populated urban area flying to one of two sites (Site A and B) in a remote northern Canadian region, which we deemed "at-risk", because healthcare services are limited and vulnerable to epidemics. Data collected between June and November 2020 on 15,873 clinical samples, indicate that molecular diagnosis allowed for identification of 13 infected individuals, who would have otherwise been missed by using solely nonpharmaceutical interventions. Overall, no outbreaks, COVID-19-related or other, were detected at the point of travel up to December 2021 since the implementation of the laboratory, suggesting this screening process is an effective means to protect at-risk communities. The success of this study suggests a process more practical than travel bans or an unfocused screening of air travelers everywhere.

Figure 1

Individuals were infected with SARS-CoV-2, as identified by RT-PCR at the airport or Site A laboratory. In total, 13 individuals were identified as positive for SARS-CoV-2. Of those, 11 were identified at the airport’s laboratory, while 2 were identified at the laboratory established at Site A. Of the 11 travelers identified, one was intended for an international business trip (Case #1), two were traveling to Site B (Case #2 and #3), while the other eight individuals were either symptomatic and refused boarding, or they were scheduled to head to Site A (Case #4, #5, #6, #8, #9, #11, #12, and #13). For the remaining two cases, one was identified through random testing at Site A (Case #7), and one was identified as a close contact of Case #9 (Case #10), who sat beside each other on the plane to Site A. Interestingly, Case #1 was the very first presumptive positive case identified at the airport’s laboratory on the very first day of operations.