Q&A: Developing a device to detect airborne COVID-19 pathogens

After the launch of its AerolSense Bioaerosol Sampler which aims to detect airborne pathogens, including COVID-19, Med-Tech Innovation News caught up with Thermo Fisher Scientific to find out more. 

Tell us about the development of the AerosolSense Bioaerosol Sampler – what technology went into its development?

The AerosolSense Sampler is an in-air pathogen surveillance solution, which collects representative aerosol samples of ambient air and traps in-air pathogens on a collection substrate. The sample can be readily analysed through subsequent laboratory testing using the golden standard polymerase chain reaction (PCR) methodology. Confirming the presence of pathogens like SARS-CoV-2 in a space during a known time interval enables decision makers in hospitals and other indoor facilities to take actions to protect their employees and provide the public with confidence.

The technology of the AerosolSense Sampler allows to capture the virus in the air before it touches the surfaces, therefore capturing aerosolised pathogens and gaining time-relevant data points for improved risk assessment. Its robust system capabilities include highly sensitive aerosol collection and separation technology to deliver consistent performance across different indoor environments.

The AerosolSense Sampler is complementary to individual screening programs, and further supports institutions with monitoring and improving their facility safety protocols.

What materials were used to make the physical device?             

The enclosure is made of stainless steel. The inside of the sampler, printed circuit board assemblies and blower are made of aluminium. The sample cartridge is made of polypropylene. 

How does it alert people to the presence of COVID-19 pathogens in the air?

The AerosolSense Sampler collects air samples through an omnidirectional inlet. A sample cartridge installed into the sampler contains the collection substrate. The air sample is directed toward the collection substrate through an accelerating slit impactor. Particles are trapped on the collection substrate as the air is drawn through the sampler. After the sampling cycle the sample cartridge is removed and sent to a testing laboratory. The laboratory uses PCR testing tests to detect the presence or absence of SARS-CoV-2. Samples are tested using Applied Biosystems TaqPath COVID-19 Combo Kit, a highly sensitive multiplex diagnostic solution.

Is this purely for use in the clinical setting, or can it be used in the public setting too?

While the focus for the initial launch is hospitals and nursing homes, the AerosolSense Sampler can be used in academic institutions (classrooms, cafeterias, lecture halls and common spaces), military scenarios, detention centres, manufacturing facilities, restaurants and other service businesses, employee break rooms, religious facilities and government facilities.

In terms of sampling, how accurately does it detect COVID-19 pathogens? 

Recent data from the University of Oregon, pending publication, demonstrated viral detection in aerosols was found to be consistent and reproducible when tested in a laboratory bench-scale setting and in a full-scale built environment. Aerosol SARS-CoV-2 detection was found to be robust against high levels of household dust, even at low viral concentrations.

The results presented above demonstrate the sensitivity of the AerosolSense Sampler to detect SARS-CoV-2 RNA when paired with either the AerosolSense substrates or flocked swabs. 

Consistent detection of SARS-CoV-2 was achieved at aerosol concentrations in accordance with currently published aerosol concentrations found in healthcare settings and detection was not significantly impacted at higher levels of air changes per hour or across different humidity levels and processing durations. All together, these results provide strong evidence for the sensitivity of the AerosolSense Sampler as an environmental surveillance solution for in-air pathogens like SARS-CoV-2 in a wide-range of indoor public spaces.

Has this been previously used before and is repurposed for today, or is this a totally new device?

While the technology of high flow aerosol sampling has been employed for biohazard surveillance to combat bioterrorism and accidental release of high-level biohazards, this is an aerosol sampling system with the unique ability to identify virus-containing aerosols within a built environment. 

Anything else you’d like to add? 

As society returns to pre-pandemic activities, expanded and complementary monitoring of environments will be key in providing useful insights into virus presence. The AerosolSense Sampler is the next step in providing institutions with highly reliable information to help keep their employees and the public safe.  

For more information, read about the launch here and information about the product here at: www.thermofisher.com/aps.