Viruses that affect humans, animals and plants are often dispersed and transmitted through airborne routes of infection. Due to current technological deficiencies, accurate determination of the presence of airborne viruses is challenging. This shortcoming limits our ability to evaluate the actual threat arising from inhalation or other relevant contact with aerosolized viruses. To improve our understanding of the mechanisms of airborne transmission of viruses, air sampling technologies that can detect the presence of aerosolized viruses, effectively collect them and maintain their viability, and determine their distribution in aerosol particles, are needed. The latest developments in sampling and detection methodologies for airborne viruses, their limitations, factors that can affect their performance and current research needs, are discussed in this review. Much more work is needed on the establishment of standard air sampling methods and their performance requirements. Sampling devices that can collect a wide size range of virus-containing aerosols and maintain the viability of the collected viruses are needed. Ideally, the devices would be portable and technology-enabled for on-the-spot detection and rapid identification of the viruses. Broad understanding of the airborne transmission of viruses is of seminal importance for the establishment of better infection control strategies.

https://sfamjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/jam.14278

Collection, particle sizing and detection of airborne viruses.

Fast and reliable detection of viruses, including those specific to bacteria – bacteriophages – is crucial in clinical and veterinary practice, during biotechnological processes, and in basic research. In this paper, a highly sensitive long-period fiber grating (LPFG) label-free immunosensor is described for the detection of T7 bacteriophages. The LPFGs were tuned up to their highest refractive index sensitivity at the dispersion turning point of higher order cladding modes. The simple and reliable fiber surface functionalization was performed using 3-(triethoxysilyl)propylsuccinic anhydride to covalently bind anti-T7 antibodies. The T7 phage detection was possible by tracing the shift of the resonance wavelength in the LPFG transmission spectrum caused by the increase of the thickness and density of the bio-overlay, in particular induced by antigen-antibody interactions. The obtained sensor was selective and the limit of detection was lower than 5 × 10 3  PFU/mL. Moreover, regeneration of the sensor surface by removing all organic layers was demonstrated. The regeneration procedure can reduce the costs of production and give the possibility for performing other measurements on the same LPFG structure. The applied procedure enabled real-time measurements and can be easily extended for the detection of other viruses.

Long-period fiber grating sensor for detection of viruses

Advancements in SPR biosensing technology: An overview of recent trends in smart layers design, multiplexing concepts, continuous monitoring and in vivo sensing

Bacterial pathogens were detected from human exhaled breath using a novel protocol

Airborne influenza viruses are responsible for serious respiratory diseases, and most detection methods for airborne viruses are based on extraction of nucleic acids. Herein, vertical-flow-assay-based electrochemical paper immunosensors were fabricated to rapidly quantify the influenza H1N1 viruses in air after sampling with a portable electrostatic particle concentrator (EPC). The effects of antibodies, anti-influenza nucleoprotein antibodies (NP-Abs) and anti-influenza hemagglutinin antibodies (HA-Abs), on the paper sensors as well as nonpulsed high electrostatic fields with and without corona charging on the virus measurement were investigated. The antigenicity losses of the surface (HA) proteins were caused by H2O2 via lipid oxidation-derived radicals and 1O2 via direct protein peroxidation upon exposure of a high electrostatic field. However, minimal losses in antigenicity of NP of the influenza viruses were observed, and the concentration of the H1N1 viruses was more than 160 times higher in the EPC than the BioSampler upon using NP-Ab based paper sensors after 60 min collection. This NP-Ab-based paper sensors with the EPC provided measurements comparable to quantitative polymerase chain reaction (qPCR) but much quicker, specific to the influenza H1N1 viruses in the presence of other airborne microorganisms and beads, and more cost-effective than enzyme-linked immunosorbent assay and qPCR.

Rapid Airborne Influenza Virus Quantification Using an Antibody-Based Electrochemical Paper Sensor and Electrostatic Particle Concentrator.

Multiplexed Surface Plasmon Resonance based real time viral aerosol detection

Aims
A portable bioaerosol monitor is highly demanded technology in many areas including air quality control, occupational exposure assessment and health risk evaluation, environmental studies and, especially, in defence and bio-terrorism applications. Our recent groundwork allowed us to formulate the concept of a portable bioaerosol monitor, which ought to be light, user friendly, reliable and capable of detecting airborne pathogens within 1 -1.5 hours at the spot.

Methods and Results
Conceptually, the event of bioaerosol concentration burst is determined by triggers, commencing representative air sampling with sequential real-time PCR confirmation of the targeted microorganism presence in the air. To minimise the reagent consumption and idle running of the technology, an event of the bioaerosol burst is confirming by three parameters: aerosol particles size, concentration and composition. The only particles sizes above 200 nm attract interest towards the bioaerosol. The only elevated aerosol concentration above the threshold (background aerosol concentration) is a signal for analytical procedure commencement. The combination of our previously developed personal bioaerosol sampler, aerosol particle counter based trigger and portable real-time PCR device formed the basis of bioaerosol monitoring technology. The portable real-time PCR device was advanced to provide the internally controlled detection, significantly reducing false positive alarms.

Conclusions
The technique is capable to detect selected airborne microorganisms at a spot within 30 – 80 minutes, depending on the particular strain genome organisation.

Significance and Impact of Study
Due to recent outbreaks of infectious airborne diseases and the continuing threat of intentionally-released bioaerosol attacks, investigations into the possibility of early and reliable detection of pathogenic microorganisms in the air is becoming increasingly important. The proposed technology consisting of a bioaerosol sampler, technology trigger and PCR device is capable to detect selected airborne microorganisms at a spot within short time period.

This article is protected by copyright. All rights reserved.

Elina Agranovski

Papers

Multiplexed Surface Plasmon Resonance based real time viral aerosol detection

Miniature PCR based portable bioaerosol monitor development.