SARS-CoV-2 screening strategies for returning international travellers: Evaluation of a rapid antigen test approach

Background: International travel poses the risk of importing SARS-CoV-2 infections and introducing new viral variants into the country of destination. Established measures include mandatory quarantine with the opportunity to abbreviate it with a negative rapid antigen test (RAT). Methods: A total of 1,488 returnees were tested for SARS-CoV-2 with both PCR and RAT no earlier than 5 days after arrival. We assessed the sensitivity and specificity of the RAT. Positive samples were evaluated for infectivity in vitro in a cell culture outgrowth assay. We tracked if participants who tested negative were reported positive within 2 weeks of the initial test. Results: Potential infectiousness was determined based on symptom onset analysis, resulting in a sensitivity of the antigen test of 89% in terms of infectivity. The specificity was 100%. All positive outgrowth assays were preceded by a positive RAT, indicating that all participants with proven in vitro infectivity were correctly identified. None of the negative participants tested positive during the follow-up. Conclusions: RAT no earlier than the 5th day after arrival was a reliable method for detecting infectious travellers and can be recommended as an appropriate method for managing SARS-CoV-2 travel restrictions. Compliance to the regulations and a high standard of test quality must be ensured. (C) 2022 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.

Automated summary

This study evaluated the sensitivity and specificity of rapid antigen testing for detecting infectivity in travelers with SARS-CoV-2. The results showed that testing with rapid antigen tests on the 5th day after arrival can reliably identify infectious travelers. No cases were found where negative travelers tested positive during the follow-up.