The COVID-19 pandemic has completely changed the way we look at hygiene, occupational health and public safety protocols, especially in professions such as medical and dental where close contact with people is a requirement. In the early stages of the worldwide pandemic, there was much controversy around how SARS-CoV-2 was transmitted across the community. World Health Organization and the US Centers for Disease Control had maintained that transmission occurred through inhaling respiratory droplets from an infected person or touching a contaminated surface and then your eyes, nose or mouth. The medical and dental professions were concerned about aerosol generating procedures (AGPs) which produce relatively large droplets and dismissed smaller particles that are emitted from exhaled breath. New guidance agrees that aerosol transmission of virus particles is not only likely, but that aerosol particles can remain in the air for significant periods of time after an infected person has left the room. Small aerosol particles containing virus can be exhaled when talking or just breathing. This leaves a new dilemma for the dental profession. How can I trust that my office is safe from infectious diseases that spread through the air?
This presentation describes an advanced method of airborne virus sampling formerly used only by aerosol scientists: condensation growth tube (CGT) capture. This approach has now been configured as a portable instrument for use by non-aerosol experts for sampling bioaerosols in indoor spaces. The CGT’s cold-hot temperature zones create water vapor supersaturation forcing condensation onto particles to form a fog of microdroplets. These droplets are gently collected keeping viruses, bacteria and fungal spores intact. The unique advantages of the CGT are: (1) high collection efficiency directly onto a sterile swab (>95% of particles from <10 nm to 10 µm), (2) instant genomic preservation of DNA/RNA upon capture, and (3) concentrated sample collection compatible with standard genomic analyses such as RT-qPCR and DNA/RNA sequencing. The work flow for sample analysis is identical to that used in diagnostic testing of nasal swabs.