Abstract
Background
Seasonal influenza (flu) occurs annually, causing disease with substantial morbidity and mortality. Currently, flu is suspected from clinical features, but requires a laboratory test to confirm infection. No influenza tests in the United States are approved for use outside of clinical settings. We aimed to determine the accuracy of influenza self-testing using an at-home, app-guided, lateral flow assay compared with a molecular reference standard conducted at a laboratory among adults self-reporting influenza-like illness (ILI).
Methods
This is an observational study of individuals with self-reported ILI throughout the continental 48 United States recruited from the Flu Near You platform, online marketing, and clinics in the Seattle area. Recruitment took place from March 4 to April 26, 2019. Participants were directed to an iPhone App that determined eligibility, consent, and responses to symptom questions and risk factors. Individuals were mailed a commercially available CLIA-waived influenza lateral flow test to conduct at home, guided by the app, and returned the used test along with a second nasal swab collected in viral transport media to the research team. Influenza testing was performed by RT–PCR on the second nasal swab, as well as the residual fluid from the RDT. Accuracy of home test result (read by the participant), as well as image capture of the lateral flow test strip, were compared with the lab-based reference standard.
Results
To date, 1127 at-home flu tests were mailed to participants and 711 (63.1%) samples returned to the lab. There were 17 flu-positive results from the rapid diagnostic test for a flu positivity rate of 2.4%. Testing using the reference standard is currently in progress. We will share diagnostic accuracy results once testing of the reference standard is completed. Of the kits returned, 353 (49.7%)had an error recorded, which included errors in return packaging, reference standard, rapid test tube sample, or rapid test strip errors.
Conclusion
Overall, findings from this study will determine the accuracy of an at-home rapid diagnostic test, and inform more widely research design for evaluating smartphone-enhanced home tests for pathogens. Many samples returned to the lab had a recorded error, suggesting at-home testing requires additional feasibility testing and refinement of the current methods used.
Disclosures
All authors: No reported disclosures.
A low-cost smartphone-based platform for highly sensitive point-of-care testing with persistent luminescent phosphors
