Efficacy of Unsupervised Self-Collected Mid-Turbinate FLOQSwabs for the Diagnosis of Coronavirus Disease 2019 (COVID-19)

Abstract

The Global Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic has resulted in explosive patterns of transmission in most countries. Nasopharyngeal swabs were the specimen's collection tools recommended for the diagnosis of SARS-CoV-2 infection, and for monitoring infection outbreaks in communities. Our objective was to report the quality and efficacy of unsupervised self-collected mid turbinate "dry FLOQSwabs" (MT FLOQSwabs) (56380CS01, Copan). There were 111 specimens collected for the study: 36 by health care personnel, from themselves, to verify the quality and efficacy of mid-turbinate swabs; 75 to compare and assess the diagnostic performance, among health care personnel, of nasopharyngeal swabs and self-collected mid-turbinate FLOQSwabs. A collection of 51 specimens was enrolled to define the efficacy of the Testami program (validation). Our analyses demonstrate that self-collected mid-turbinate dry swabs ensure an accuracy of 97.3%, as compared to the standard nasopharyngeal swabs collected by health care workers. Furthermore, the mid-turbinate FLOQSwabs can be stored without medium for six days at room temperature without affecting the molecular diagnosis of the SARS-CoV-2 virus infection. Self-collection of diagnostic specimens at home could offer an avenue to increase testing availability for SARS-CoV-2 infection without asking people to travel to a clinic or a laboratory, thus reducing people's exposure to infection. Our findings demonstrate that unsupervised self-collection swabs, transported dry, are sensitive, practical and easy-to-use tools and should be considered for diagnosis of SARS-COV-2 and coronavirus disease 2019 (COVID-19) surveillance.

Keywords: SARS-CoV-2; dry swab; surveillance; unsupervised self-collection.

Figure 1

Contoured FLOQSwabs w/STOPPER mid-turbinate nasal flocked swabs (MT FLOQSwabs) (56380CS01, Copan) (top) compared to flocked nasopharyngeal FLOQSwabs. Adapted from Smieja et al. (bottom). Blank arrow indicates the “stopper”; red arrow indicates the break point.

Figure 2

Profile of subjects enrolled for the different phases of the study.

Figure 3

Graphical representation of SC and HCP swabs correlation. (A) Scatter plot showing the b-globin levels detected in self-collected (SC) and healthcare worker-collected (HCP) samples. Note that Ct values are above the cut-off value (35 Ct) in seven SC samples and 11 HCP samples. (B) Correlation of Ct values of viral genes (average) detected in SC and HCP swabs (N = 75). Pearson’s correlation test, r = 0.8784 (CI 95% 0.8136–0.9216), p < 0.0001.

Figure 4

Representation and validation of Testami program. (A) Schematic representation of Testami program. (B) Correlation of Ct values of viral genes in sample collected using the Testami program and by standard procedures, Spearman’s test r = 0.8608 (CI95%: 0.7685 to 0.9180), p value < 0.0001 (left panel); correlation of Ct values of B-globin gene in samples collected using the Testami program and by standard procedures (Spearman’s test r = 0.4318 (CI95%: 0.2889 to 0.5559), p value < 0.0001 (right panel).