Disease-specific VOCs can be detected from different biological materials.

IMS is a semi-quantitative detection method for VOCs from urine.

IMS can separate urine of Covid-19 patients and symptomatic PCR-negative controls.

A 3-step decision tree results in sensitivity and specificity of 98% each.

SARS-CoV-2 is usually diagnosed from naso-/oropharyngeal swabs which are uncomfortable and prone to false results. This study investigated a novel diagnostic approach to Covid-19 measuring volatile organic compounds (VOC) from patients’ urine.

Between June 2020 and February 2021, 84 patients with positive RT-PCR for SARS-CoV-2 were recruited as well as 54 symptomatic individuals with negative RT-PCR. Midstream urine samples were obtained for VOC analysis using ion mobility spectrometry (IMS) which detects individual molecular components of a gas sample based on their size, configuration, and charge after ionization.

Peak analysis of the 84 Covid and 54 control samples showed good group separation. In total, 37 individual specific peaks were identified, 5 of which (P134, 198, 135, 75, 136) accounted for significant differences between groups, resulting in sensitivities of 89–94% and specificities of 82–94%. A decision tree was generated from the relevant peaks, leading to a combined sensitivity and specificity of 98% each.

VOC-based diagnosis can establish a reliable separation between urine samples of Covid-19 patients and negative controls. Molecular peaks which apparently are disease-specific were identified. IMS is an additional non-invasive and cheap device for the diagnosis of this ongoing endemic infection. Further studies are needed to validate sensitivity and specificity.

Covid-19

Urine

VOC

Electronic nose

Smell prints

Diagnostics

IMS

© 2024 The Authors. Published by Elsevier B.V.