Our results show that the nasopharyngeal swab specimen collection is associated with a high occurrence of defense reflexes of sneezing and coughing triggered by the contact of the nasopharyngeal mucosa with the swab. Here we have shown that AGEs have occurred in both uninfected and infected persons, being triggered in more than 1 in 5 participants to nasopharyngeal swabbing. This can become a concern when many infected participants show up to testing as it creates the conditions for airborne viral spreading. AGEs have the potential of contaminating the ambient air and the surrounding surfaces, posing potential contamination risks for the following participants to testing and also for the following collected specimens.
As effective decontamination procedures can be easily applied on the empty specimen collecting room, this can become controversial when decontamination is required in between participants in which AGEs such as reflexes of sneezing and coughing have occurred. Here, the use of an UV light lamp is impractical as it requires eye and skin protection for the room occupants and a prolonged period of exposure for efficacy, while applying disinfectants with the participants inside can be a delicate subject. However, safer alternatives could be used to limit the risk of infecting other participants and contaminating subsequent samples after the occurrence of an AGE.
STRATEGIES OF LOWERING THE ODDS OF CONTAMINATION FROM AN AGE
Providing adequate ventilation and volume of air
Providing adequate ventilation to the sampling room could ensure that the viral load in the ambient air will stay at low levels from air exchanges with the exterior. A natural ventilation is preferred against mechanical ventilation systems since air recirculation devices can accommodate and potentially mobilize viral particles in the air from exhaust outlets. In cold weather, the air exchanges with the exterior through open windows may ensure a higher rate of air replacement through inside-outside temperature differences contributing to a faster clearance of the viral load in the ambient air of the warmer testing room. The total volume of air in the sampling room is of equal importance, since aerosols tend to become dispersed in the total volume of air. This is why the bigger the sampling room, the more increased the total volume of air will be, leading to a more reduced concentration of the viral load in the ambient air after the occurrence of an AGE. Therefore, the ideal sampling room with regards to an adequate volume of air will be the biggest room in the building with as little furniture as possible and many windows for natural ventilation. This is to prevent that more than several hundred persistent copies of the virus will linger in the air in the same place at the same time to potentially become pathogenic. Waiting rooms should be replaced by a rigorous appointment schedule to prevent cramming of participants inside indoor places. A 5 minute interval between participants in our study was enough to allow the necessary time for specimen collection and decontamination while preventing the cramming of participants. If a waiting room is however indispensable, it should respect distancing and have adequate natural ventilation.
Using washable surfaces
A decontamination of surfaces should be achieved after the occurrence of an AGE before the next participant is invited in. However, this can be done if the sampling room is equipped with readily washable surfaces of tables chairs and walls, on which the decontaminants can be effectively applied. Since airborne viruses can become embedded in fabrics, the textile covering of chairs, table or windows should be avoided. Moreover, textile walls such as the ones used in military tents could accommodate viral particles after an AGE and an on-site decontamination would be impractical. Besides, such particles embedded in the fabric could be mobilized by weather conditions such as strong winds, heavy rain or hail and become airborne again. This is why containers should be preferred against military tents to provide proper cleaning conditions for the decontamination of walls and surfaces after the occurrence of an AGE.
Keeping the facemasks over participant’s mouth
The facemask of participants becomes of vital importance as it can limit both spreading and contacting the virus. While wearing the facemask should be compulsory in the sampling rooms, its removal during the specimen collection procedure becomes necessary. However, the partial removal from the nose area while still covering the mouth can facilitate specimen collection by nasopharyngeal swab sampling, limiting viral spread through a potential AGE, while also limiting the inhalation of potential pathogenic viral aerosols lingering in the ambient air by advising the person being tested to only breath by the mask covered mouth during the specimen collection (fig.6) A lateral positioning of the examiner during sampling could potentially avoid facing the direct current of expelled infectious particles by AGEs to a greater extent than a face-to face positioning. Since the risk of contamination among frontline healthcare workers wearing a PPE is 3-fold higher than in the general population, keeping the facemasks of participant on their mouths during the nasopharyngeal swabbing and standing sideways from the direction of potential infectious particles expelled by an AGE during the nasopharyngeal swabbing could limit the contamination of the examiner and the surroundings.
Using disinfectants after an AGE
The use of chemical disinfectants or a UV lamp after an AGE can limit the contamination of the surrounding objects and the air. However, there are not many disinfectants that can be safely applied on objects and air with the participants inside, as their contact with the skin, eyes and respiratory mucosa can be harmful. This is why their use in impractical in sampling rooms, as they require the removal of all participants, a prolonged exposure time, and the proper ventilation to prevent inhalation and irritation of the respiratory tract mucosa and eyes. 70% ethylic alcohol is an effective agent against enveloped viral pathogens as it acts on the integrity of the lipid bilayer membrane of the envelope while also being relatively safe for human exposure with the least harmful effects. However, using only alcohol can leave traces of leftover intact viral genome to contaminate surfaces and test positive to the PCR analyses even if being nonpathogenic. To address this limitation, 70% ethylic alcohol can be potentiated with an adjuvant that induces structural breaks in the viral genome. Methylene blue (MB) can be used as such an adjuvant since it is safe for human use at low concentrations and it acts as a photosensitizer in association with visible light.  This induces the generation of multiple reactive oxygen species (ROS) with singlet oxygen being the most abundant, leading to depurination, guanosine oxidation and strand cross-linking, with consequent viral genome degradation. MB photooxidation was shown to be effective against multiple viral pathogens including SARS-CoV2. While alcohol can facilitate the MB passage through the viral envelope, this is done even in the absence of alcohol by the natural property of MB to cross lipid bilayer membranes and this effect is being exploited in photoinactivation procedures of the plasma and vital staining of cellular organelles being a safe agent for human use. The combined effect of alcohol and MB could address both viral pathogenicity and the risk of positive results from leftover integral viral genome and could be used in the form of spraying or steaming the air and objects after an AGE to address airborne viral particles. Such a combination is available in blue rubbing alcohol formulations. Ammonium salts in commercially available biocide products can be used as alternatives to ethylic alcohol for the decontamination of the microaerophlore, and could potentially be used in the presence of other participants wearing facemasks. Good laboratory practices such as limiting the exposure time of the nasopharyngeal swab and the opened collection tube and its cap in the ambient air could further reduce the risk of contamination of the swab from the air or the influence of decontaminants contained in the air on the results of testing.
Using the relative humidity of air after an AGE
Relative humidity (RH) of air is one of the most important factors affecting airborne virus infectivity as a direct link between the persistence, survival and pathogenesis of viral particles and RH was described. Infectivity studies show that low RH tends to conserve the infectivity of enveloped viruses, while nonenveloped viruses become more stable at high RH. It was shown that high RH is deleterious to the survival of the aerosolized enveloped coronaviruses SARS-CoV-2, MERS-CoV and HCoV-229E. Aerosolized particles tend to bind to other fluid molecules in the air by electrostatic attraction, impaction, interception and diffusion so an increased size and weight of viral aerosols will lead to a faster settling rate and a decreased inhalability. Using methods of increasing the RH of the ambient air could reduce the risk of infection after an AGE, while influencing the chemical composition of water particles using adjuvants to neutralize virions could address the airborne virions after an AGE. This could be obtained by exploiting the viral photoinactivation potential of MB   and the envelope damaging effect of ethylic alcohol together with the faster sedimentation effect induced by increased RH. Spraying or steaming MB potentiated water or alcohol in the ambient air immediately after an AGE could be an acceptable method of increasing viral sedimentation rate and the viral photoinactivation in the air and on the ground and surfaces. Moreover, adding the effect of heat to such system could increase the effect of damaging the integrity of the viral envelope. Increasing the relative humidity and temperature gas been shown to accelerate SARS-CoV-2 inactivation on surfaces.  Since the new coronavirus is shown to present a high degree resistance to physical aggressions such as mechanical forces and heat, the use of a combined decontamination strategy which may include chemical (alcohol, MB) and physical agents (heat, RH, photoinactivation) becomes justified.