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: 1,488 returnees were tested for SARS-CoV-2 with both polymerase chain reaction (PCR) and RAT no earlier than five 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 negative participants were reported positive within two 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 fifth 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.
Fuente: International Journal of Infectious Diseases