Guest Lecture on "Can Viable SARS-CoV-2 be Transmitted by Aerosol?" by Dr. Chang-Yu Wu

Our chapter organised the first UIUC AAAR Student Chapter Guest Lecture on September 24th, 2021. We invited Prof. Chang-Yu Wu from the University of Florida to give the lecture to the UIUC faculty and graduate students, with the topic, as "Can Viable SARS-CoV-2 be Transmitted by Aerosol?".

The lecture was presented over zoom and involved collaboration with the CEE 595 AG-Environmental Engineering Seminar, which was held in Newmark Civil Engineering Building 2311. More than 50 attendants (25 each on zoom and in seminar classroom) participated in this event.

Prof. Wu started the lecture by highlighting the importance and relevance of SARS-CoV-2 virus sampling and analysis under the circumstance of ongoing pandemic. Prof. Wu mentioned that the low efficiency of conventional air samplers was a major drawback in conducting research to quantify the aerosol transmission of the virus. To overcome this, Prof. Wu's research group developed a novel airborne virus sampler (Viable Virus Aerosol Sampler, VIVAS) that operates based on a laminar-flow water vapor condensation principle coupled with gentle impaction. This instrument enhanced the virus collection efficiency to 95% at distances of 2-4.8 m from the infected patients, thus facilitating the quantification of viable virus concentrations.

The virus loads were tested in three different environments: a hospital room, a fitness centre and a self-isolation room. Based on these results, Prof. Wu’s team found that the viable virus concentrations were highest in the self-isolation room, followed by the hospital room. In contrast, the fitness centre showed the least viable virus concentrations despite people not wearing a mask. The key take-away message, as delivered by Prof. Wu from his talk, was the importance of the air circulation/ventilation in the room. Rooms with higher ventilation had a significantly lower risk of transmitting the virus through aerosol. Prof. Wu concluded the lecture by bringing in the suggestions on enhancing environmental surveillance which could also identify the potential transmission risk from asymptomatic individuals who might be less included in other research designs.

The lecture was followed by a heated Q&A discussion session where participants from both zoom and the seminar classroom session were excited to interact and ask questions related to the lecture topic to Prof. Wu. During the discussion, Prof. Wu talked about the limitation of the study on the gymnasium. Since high ventilation might not be applied to all of the gyms, precautions should still be taken when starting to work out in a gym, like inquiring about the risk control actions from gym staff.

The record of this lecture have been uploaded to the Google Drive of UIUC AAAR Student Chapter official e-mail (aaaruiuc@gmail.com). The lecture can solely be used by the student chapter members for the purpose of studying. No redistribution is allowed.