Using trained dogs and organic semi-conducting sensors to identify asymptomatic and mild SARS-CoV-2 infections: an observational study.

BACKGROUND: A rapid, accurate, non-invasive diagnostic screen is needed to identify people with SARS-CoV-2 infection. We investigated whether organic semi-conducting (OSC) sensors and trained dogs could distinguish between people infected with asymptomatic or mild symptoms, and uninfected individuals, and the impact of screening at ports-of-entry. METHODS: Odour samples were collected from adults, and SARS-CoV-2 infection status confirmed using RT-PCR. OSC sensors captured the volatile organic compound (VOC) profile of odour samples. Trained dogs were tested in a double-blind trial to determine their ability to detect differences in VOCs between infected and uninfected individuals, with sensitivity and specificity as the primary outcome. Mathematical modelling was used to investigate the impact of bio-detection dogs for screening. RESULTS: About, 3921 adults were enrolled in the study and odour samples collected from 1097 SARS-CoV-2 infected and 2031 uninfected individuals. OSC sensors were able to distinguish between SARS-CoV-2 infected individuals and uninfected, with sensitivity from 98% (95% CI 95-100) to 100% and specificity from 99% (95% CI 97-100) to 100%. Six dogs were able to distinguish between samples with sensitivity ranging from 82% (95% CI 76-87) to 94% (95% CI 89-98) and specificity ranging from 76% (95% CI 70-82) to 92% (95% CI 88-96). Mathematical modelling suggests that dog screening plus a confirmatory PCR test could detect up to 89% of SARS-CoV-2 infections, averting up to 2.2 times as much transmission compared to isolation of symptomatic individuals only. CONCLUSIONS: People infected with SARS-CoV-2, with asymptomatic or mild symptoms, have a distinct odour that can be identified by sensors and trained dogs with a high degree of accuracy. Odour-based diagnostics using sensors and/or dogs may prove a rapid and effective tool for screening large numbers of people.Trial Registration NCT04509713 (clinicaltrials.gov).

Pressure and Flow Comparisons Across Vocal Pathologies.

OBJECTIVE: The aim of this study was to aid in the distinction among hyperadductive dysphonias by evaluating peak glottal pressure, release burst, and mid and final airflow values across repeated /pa/ syllable trains. METHODS: Sixty subjects were assessed for aerodynamic patterns during onset-offset for the /papapapapa/ task in modal voice. Subject groups included adductory spasmodic dysphonia (AdSD), benign vocal fold lesion, primary muscle tension dysphonia (MTD-1), secondary muscle tension dysphonia with an identifiable primary benign vocal fold lesion (MTD-2), vocal fold paresis or paralysis, and normal controls. RESULTS: Increased peak pressure (PP) was found for AdSD and MTD-2 subjects compared with controls. Release burst and mid airflow were not significantly different among groups. Final airflow was significantly higher for AdSD compared with the other groups. Final airflow was significantly lower for MTD-1. CONCLUSIONS: Significant differences in aerodynamics are seen in subjects with AdSD compared to MTD. AdSD was characterized by higher PP and higher final airflow. MTD-1 was characterized by lower final airflow, whereas MTD-2 was characterized by higher PP. Aerodynamic evaluation may aid in differential diagnosis for those patients in whom distinction among hyperadductive disorders is challenging.