Self-sampling versus health care professional-guided swab collection for SARS-CoV-2 testing

• Published in: Infection Vol. 49; no. 5; pp. 927 - 934
• Main Authors: Würstle, Silvia, Spinner, Christoph D., Voit, Florian, Hoffmann, Dieter, Hering, Svenja, Weidlich, Simon, Schneider, Jochen, Zink, Alexander, Treiber, Matthias, Iakoubov, Roman, Schmid, Roland M., Protzer, Ulrike, Erber, Johanna
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2021; Springer Nature B.V
• Subjects: COVID-19; COVID-19 diagnostic tests; COVID-19 Testing; Family Medicine; General Practice; Health care; Health Personnel; Home medical tests; Humans; Immunoglobulin G; Infectious Diseases; Internal Medicine; Medicine; Medicine & Public Health; Original Paper; Protective equipment; Reliability analysis; Reproducibility of Results; Sampling; SARS-CoV-2; Sensitivity analysis; Severe acute respiratory syndrome coronavirus 2; Viral diseases; Self-sampling; Oropharyngeal; COVID-19; Swab; SARS-CoV-2
• ISSN: 0300-8126; 1439-0973
• DOI: 10.1007/s15010-021-01614-9

Purpose
To evaluate the diagnostic reliability and practicability of self-collected oropharyngeal swab samples for the detection of SARS-CoV-2 infection as self-sampling could enable broader testing availability and reduce both personal protective equipment and potential exposure.
Methods
Hospitalized SARS-CoV-2-infected patients were asked to collect two oropharyngeal swabs (SC-OPS1/2), and an additional oropharyngeal swab was collected by a health care professional (HCP-OPS). SARS-CoV-2 PCR testing for samples from 58 participants was performed, with a 48-h delay in half of the self-collected samples (SC-OPS2). The sensitivity, probability of concordance, and interrater reliability were calculated. Univariate and multivariate analyses were performed to assess predictive factors. Practicability was evaluated through a questionnaire.
Results
The test sensitivity for HCP-OPS, SC-OPS1, and SC-OPS2 was 88%, 78%, and 77%, respectively. Combining both SC-OPS results increased the estimated sensitivity to 88%. The concordance probability between HCP-OPS and SC-OPS1 was 77.6% and 82.5% between SC-OPS1 and SC-OPS2, respectively. Of the participants, 69% affirmed performing future self-sampling at home, and 34% preferred self-sampling over HCP-guided testing. Participants with both positive HCP-OPS1 and SC-OPS1 indicating no challenges during self-sampling had more differences in viral load levels between HCP-OPS1 and SC-OPS1 than those who indicated challenges. Increasing disease duration and the presence of anti-SARS-CoV-2-IgG correlated with negative test results in self-collected samples of previously confirmed SARS-CoV-2 positive individuals.
Conclusion
Oropharyngeal self-sampling is an applicable testing approach for SARS-CoV-2 diagnostics. Self-sampling tends to be more effective in early versus late infection and symptom onset, and the collection of two distinct samples is recommended to maintain high test sensitivity.