Evaluating specimen quality and results from a community-wide, home-based respiratory surveillance study

Kim AE, Brandstetter E, Wilcox N, Heimonen J, Graham C, Han PD, Starita LM, McCulloch DJ, Casto AM, Nickerson DA, Van de Loo MM, Mooney J, Ilcisin M, Fay KA, Lee J, Sibley TR, Lyon V, Geyer RE, Thompson M, Lutz BR, Rieder MJ, Bedford T, Boeckh M, Englund JA, Chu HY on behalf of the Seattle Flu Study Investigators. 2021. J Clin Microbiol 59: e02934-20.


Introduction: While influenza and other respiratory pathogens cause significant morbidity and mortality, the community-based burden of these infections remains incompletely understood. The development of novel methods to detect respiratory infections is essential for mitigating epidemics and developing pandemic-preparedness infrastructure.

Methods: From October 2019 to March 2020, we conducted a home-based cross-sectional study in the greater Seattle area, utilizing electronic consent and data collection instruments. Participants received nasal swab collection kits via rapid delivery within 24 hours of self-reporting respiratory symptoms. Samples were returned to the laboratory and were screened for 26 respiratory pathogens and a human marker. Participant data were recorded via online survey at the time of sample collection and one week later.

Results: Of the 4,572 consented participants, 4,359 (95.3%) received a home swab kit, and 3,648 (83.7%) returned a nasal specimen for respiratory pathogen screening. The 3,638 testable samples had a mean RNase P CRT value of 19.0 (SD: 3.4) and 1,232 (33.9%) samples had positive results for one or more pathogens, including 645 (17.7%) influenza-positive specimens. Among the testable samples, the median time between shipment of the home swab kit and completion of laboratory testing was 8 days [IQR: 7.0-14.0]. A single adverse event occurred and did not cause long-term effects or require medical attention.

Discussion: Home-based surveillance using online participant enrollment and specimen self-collection is a feasible method for community-level monitoring of influenza and other respiratory pathogens, which can readily be adapted for use during pandemics.