Ventilation control of Covid-19 and other pathogen aerosols

Sass 3100 sampling air from air duct

A challenge for Chief Medical & Biosafety Officers: the asymptomatic spread of Delta variant or other virus in public spaces.

Personnel with valid PCR or antigen tests, or fully vaccinated but in contact with a Delta-positive case, may remain asymptomatic carriers of the Delta variant, as the average incubation period is four days before reaching sufficient viral load to be detected by a valid PCR test, and it takes even more days to reach viral load detectable by antigen test kits.

In comparative studies collecting worldwide data on clinical samples, only 58% of asymptomatic Covid-19 carriers have been diagnosed positive by antigen testing.

According to a recent US study, the Covid-19 viral load in vaccinated healthcare workers was only 40% lower than in unvaccinated workers, at a time when the Delta variant was not predominant. However, a recent study of fully vaccinated health workers in various Indian hospitals found even higher respiratory viral loads.


All these raised issues, are very challenging for Chief Medical Officers to prevent outbreaks and asymptomatic spread of Delta and other future variants among staff, or customers.

Great efforts have been made to reduce these risks, including massive vaccination campaigns, but the Delta variant is highly contagious and is known to evade immunity acquired through vaccination.
In addition, more virulent strains may emerge in the future, as Israel is already reporting 50% hospitalisations for severe Covid with the Delta variant among fully vaccinated people.

A new tool to detect Delta variant & other airborne pathogens hot spots

A new electret filter capture was validated for high-flow collection of viral aerosols in public transport enables chief Medical Officer or Biosafety officer to detect specific hot spots where Delta and other airborne pathogens may spread in respiratory aerosols.

Efficient extraction and Rt-Pcr analysis protocols have been developed using this new high-flow electret aerosol capture of virus particles.

Sass 3100 aerosol sampling for the detection of pre-symptomatic contaminated hot spots.
Sass 3100 vent duct viral particles sampling
Sass 3100 high flow electret capture of viral particles in vent duct

High flow air sampling efficiently capturing viral particles travelling in air exhaust ducts, to concentrate large volume of air of specific areas, will enable to spot eventually areas where Sars-cov-2 variants are released by asymptomatic carriers, before onset of symptoms.

This enables for example Cruise ship Medical Officers to improve the efficiency of their protective measures and reduce the spread of an early detected hot zone to other passenger cabin areas or decks.

Regular checking of air handling units and filtration efficiency allows to detect abnormal filter clogging and leaks.

Continuous air sampling inside the flight cabin air extraction system allows to concentrate large volumes of air and detect if Delta or other new variants were released during a specific flight.

Delta 1000 times more virus in air than with Wuhan strain makes it easier to collect & detect.

Delta variant viral load in naseopharyngeal samples are 1000 times more concentrated than for the Wuhan original strain, this means also that respiratory emissions can have very high load of virus shed in air..

So Delta variant viral particles shedding could be more easily detected in high volume aerosols as Sass 3100 air sampling technology can collect large volume for hours without filter plugging.


Validated protocols developped for Sass 3100 electret filter Rna analysis.
sass 3100 Rna filter extraction and analysis

viral RNA can be easily extracted from Sass 3100 electret filter and analyzed by reverse transcriptase PCR