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Optimal use of COVID19 Ag-RDT screening at border crossings to prevent community transmission: a modeling analysis
Joshua M Chevalier; Karla Therese L. Sy; Sarah J Girdwood; Shaukat Khan; Heidi Albert; Amy Toporowski; Emma Hannay; Sergio Carmona; Brooke E Nichols.
Affiliation
  • Joshua M Chevalier; Department of Global Health, Boston University School of Public Health, Boston, MA, USA
  • Karla Therese L. Sy; Department of Epidemiology, Boston University School of Public Health; Department of Global Health, Boston University School of Public Health
  • Sarah J Girdwood; Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the W
  • Shaukat Khan; Clinton Health Access Initiative, Boston, MA, USA
  • Heidi Albert; FIND, Cape Town, South Africa
  • Amy Toporowski; FIND, Geneva, Switzerland
  • Emma Hannay; FIND, Geneva, Switzerland
  • Sergio Carmona; FIND, Geneva, Switzerland
  • Brooke E Nichols; Department of Global Health, Boston University School of Public Health; Health Economics and Epidemiology Research Office, Department of Internal Medicine, Scho
Preprint in En | PREPRINT-MEDRXIV | ID: ppmedrxiv-21256154
ABSTRACT
BackgroundCountries around the world have implemented restrictions on mobility, especially cross-border travel to reduce or prevent SARS-CoV-2 community transmission. Rapid antigen testing (Ag-RDT), with on-site administration and rapid turnaround time may provide a valuable screening measure to ease cross-border travel while minimizing risk of local transmission. To maximize impact, we developed an optimal Ag-RDT screening algorithm for cross-border entry. MethodsUsing a previously developed mathematical model, we determined the daily number of imported COVID-19 cases that would generate no more than a relative 1% increase in cases over one month for different effective reproductive numbers (Rt) of the recipient country. We then developed an algorithm- for differing levels of Rt, arrivals per day, mode of travel, and SARS-CoV-2 prevalence amongst travelers-to determine the minimum proportion of people that would need Ag-RDT testing at border crossings to ensure no greater than the relative 1% community spread increase. FindingsWhen daily international arrivals and/or COVID-19 prevalence amongst arrivals increases, the proportion of arrivals required to test using Ag-RDT increases. At very high numbers of international arrivals/COVID-19 prevalence, Ag-RDT testing is not sufficient to prevent increased community spread, especially for lower levels of Rt. In these cases, Ag-RDT screening would need to be supplemented with other measures to prevent an increase in community transmission. InterpretationAn efficient Ag-RDT algorithm for SARS-CoV-2 testing depends strongly on Rt, volume of travel, proportion of land and air arrivals, test sensitivity, and COVID-19 prevalence among travelers. FundingUSAID, Government of the Netherlands
License
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Full text: 1 Collection: 09-preprints Database: PREPRINT-MEDRXIV Type of study: Observational_studies / Prognostic_studies / Rct Language: En Year: 2021 Document type: Preprint
Full text: 1 Collection: 09-preprints Database: PREPRINT-MEDRXIV Type of study: Observational_studies / Prognostic_studies / Rct Language: En Year: 2021 Document type: Preprint