Does a negative COVID-19 test before air travel reduce the spread of COVID-19 infection during and after travel?

In a recent study published in Weekly reports of morbidity and mortalityresearchers evaluated the impact of predeparture testing on post-arrival severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity rates in international travelers.

Background

Beginning December 6, 2021, international travelers boarding flights to the United States must have a negative SARS-CoV-2 result obtained within one day of departure or I had to present one of the recovery confirmations. 90 days. Starting June 12, 2022, her pre-departure COVID-19 test is no longer required, but is still recommended by the Centers for Disease Control and Prevention (CDC). Several modeling studies estimate that predeparture testing on the day before or on the day of travel reduces SARS-CoV-2 transmission or importation by approximately 31% to 76%.

About research

In this study, researchers evaluated the impact of pre-departure COVID-19 testing on post-arrival test results in international travelers.

A traveler-based genomic surveillance program has discovered novel and developing SARS-CoV-2 variants to monitor travelers at international airports and facilitate global surveillance. Her 18+ international passenger volunteers arrive at the airport in Atlanta, Georgia. New York, New York; Newark, New Jersey. San Francisco, CA provided samples of infranasal swabs after arrival at the airport.

Participants completed a structured questionnaire asking demographic information, flight origin, whether COVID-19 testing was performed prior to departure, and whether molecular or antigen testing was performed.

Dried nasal swab specimens were collected by flight country of origin. The Ginkgo Bioworks Laboratory Network Laboratory has received pooled samples for reverse transcription-polymerase chain reaction (RT-PCR) testing for SARS-CoV-2. The team reviewed post-arrival RT-PCR test results from March 20 to June 11, when pre-departure testing was mandatory, and June 12 to September, when pre-departure assessment was optional. We compared results up to 3 days.

result

Between 20 March and 3 September 2022, approximately 28,056 travelers arriving from 24 countries were screened for SARS-CoV-2, with an average sample of 8 participants per pool. A pooled sample of 3,049 with From March 20 to June 11, approximately 13,190 of the 16,668 participants reported having undergone predeparture screening.

However, between 12 June and 3 September, this proportion dropped by 80% to 1,786 out of 11,123 who reported having undergone pre-departure testing. Antigen testing was also performed on 10,349 of the 14,976 travelers who indicated the type of predeparture test.

The team noted that 691 of the 3,049 sample pool tested positive for SARS-CoV-2 by RT-PCR during the analysis period. The percentage of the positive pool increased from 17.9% to 56% between March 20th and June 11th, and decreased to 28.0% between June 12th and September 3rd. The increase in the percentage of post-arrival positive test findings from 20 March to 11 June and from 12 June to 3 September was consistent across countries, collection airports, pool sizes, and incidence rates. was evident in both bivariate and univariate logistic regressions. Individuals participating in the study during each period were similar in gender and age.

Multivariable model results were collected between 20 March and 11 June, after statistical adjustments were made for flight pool size, country of origin, and COVID-19 incidence at collection airport. sample pools were 52% less likely to be tested. SARS-CoV-2 positivity compared to that collected when predeparture assessment was optional.

Conclusion

Findings show that if pre-departure COVID-19 testing is mandatory, positive post-arrival COVID-19 test results are more likely compared to the 12-week period after testing was considered optional. was shown to be fairly low. Based on observed real-world traveler information, these results confirmed the efficacy of pre-departure testing as a technique to reduce travel-related SARS-CoV-2 transmission.