Feasibility and utility of facemask sampling in the detection of SARS-CoV-2 during an ongoing pandemic

Abstract

s Easy access to screening for timely identification and isolation of infectious COVID-19 patients remains crucial in sustaining the international efforts to control COVID-19 spread. A major barrier limiting broad-based screening is the lack of a simple, rapid, and cost-effective COVID-19 testing method. We evaluated the feasibility and utility of facemask sampling in a cohort of 42 COVID-19-positive and 36 COVID-19-negative patients. We used a prototype of Steri-Strips™ (3 M) applied to the inner surface of looped surgical facemasks (Assure), which was worn by patients for a minimum wear time of 3 h, then removed and sent for SARS-CoV-2 PCR testing. Baseline demographics and symptomatology were also collected. Facemask sampling positivity was highest within the first 5 days of symptomatic presentation. Patients with nasopharyngeal and/or oropharyngeal swab SARS-CoV-2 PCR Ct values < 25.09 had SARS-CoV-2 detected on facemask sampling, while patients with Ct values ≥ 25.2 had no SARS-CoV-2 detected on facemask sampling. Facemask sampling can identify patients with COVID-19 during the early symptomatic phase or those with high viral loads, hence allowing timely identification and isolation of those with the highest transmission risk. Given the widespread use of facemasks, this method can potentially be easily applied to achieve broad-based, or even continuous, population screening.

Exhaled SARS-CoV-2 RNA viral load kinetics measured by facemask sampling associates with household transmission

“…Previous studies using sampling from modified facemasks have not assessed longitudinal RNA VL kinetics. [5][6][7][8][9]12] Our findings are consistent with findings from the Gesundheit II-exhaled breath collector (GII). [19] Here, higher RNA VL were observed in exhaled breath within those who were sampled once, on day 3 after symptom onset.…”

“…While there are single point assessments of exhaled virus by different methods, no clear picture exists of the natural history of SARS-CoV-2 emission. [4][5][6][7][8] Facemask sampling (FMS) offers particular advantages for assessment of exhaled virus output over multiple sampling periods. [9] FMS can be performed within the comfort of patients' own homes and the methodology is replicable in most routine laboratories.…”

Recent advances in facemask devices for in vivo sampling of human exhaled breath aerosols and inhalable environmental exposures

“… Exhaled aerosols Analytes Types of facemasks Detection limits Analytical approaches Ref. Bacteria Mycobacterium tuberculosis FFP3 facemask 100-100 qPCR [ 28 ] CFU Mycobacterium tuberculosis N95 facemask Ct value: 29 qPCR [ 31 ] Antimicrobial resistance genes Modified FFP1 facemask with gelatin filter Ct value:100 qPCR [ 32 ] Unspecified Bacteria Surgical facemask loaded with 3D-PVA NA Unspecified [ 33 ] Viruses Rhinovirus, Influenza A virus, and Parainfluenza virus Homemade facemask by PVA NA PCR [ 41 ] Bacillus atrophaeus, Bacteriophage MS2 Homemade by cotton t-shirt fabric and surgical mask NA Henderson apparatus [ 42 ] SARS-CoV-2 Modified cup-type N95 mask with a gelatin membrane Ct value: 27.29 RT-PCR [ 48 ] SARS-CoV-2 Modified duckbilled surgical facemask containing 3D-PVA ≤999 copies/strip RT-qPCR [ 49 ] SARS-CoV-2 Surgical facemasks with three Steri-Strips Ct value: 25.2 RT-qPCR [ 50 ] SARS-CoV-2, HCov-NL63 CPAP-type 10 to 100 copies/flte RT-qPCR [ 51 ] Proteins Cytokines Hard-surface plastic masks, disposable hospital paper masks NA ICA ...…”

“…Williams et al [ 49 ] collected exhaled SARS-Cov-2 by wearing facemask ( Figure 4 d) and found a potentially significant relationship between facemask sampling and nasopharyngeal swabs viral load which demonstrated a pick-up rate of 65-70% in those which were concomitantly nasopharyngeal swabs positive. Ng et al [ 50 ] systematically evaluated the feasibility of facemask for detecting exhaled SARS-CoV-2, showing that facemask sampling had a pick-up rate of 62.6-87.5% of patients who were tested within the first 5 days of symptom onset. Moreover, Smolinska et al [ 51 ] developed filter-modified CPAP-type face mask to capture exhaled virus particles.…”

“…Further studies on improving the facemask viral breath sampling are still highly needed to facilitate facemask as a practical clinical tool. Purposeful open-mouth breathing or coughing [ 50 ], long time facemask wearing [ 52 ], and a designed collector in facemask ( Figure 4 f) [ 53 ] might help to increase sampling efficiency and sensitivity.…”