During the study's time frame, the Kingston, Frontenac, Lennox & Addington (KFL&A) public health region reported 1,494 confirmed cases of COVID-19 (Fig. 2). The test positivity rate ranged between 0.0–2.01% (May 8, 2021). 35.91% and 45.7% of cases were identified as B.1.1.7 (alpha) B.617.2 (delta), respectively. KFL&A was considered a low prevalence area for COVID-19 throughout the first, second and third wave. However, the highest prevalence of COVID-19 cases occurred in the 18- to 29-year-old age category (697 cases; 46.7%) in the highest population density area, including the downtown core in which many students live . Additionally, some students engaged in intra-provincial, national, and international travel throughout the study for personal or training-related purposes (i.e., residency placements in other cities), which may have further increased their risks (data not presented). Many students engaged in some form of in-person learning component during this study; however, some programs had more frequent and higher risk contact than others (e.g., simulation vs. working directly with patients) (data not presented).
Despite these potential increased risks to COVID-19 exposure, our study revealed that asymptomatic RT-PCR NP testing of a higher risk occupational group from a geographical location with a low COVID-19 prevalence rate revealed no detectable SARS-CoV-2 infection. Further, there were limited COVID-19 cases within the hospital during the study, meaning that the risk of a health care professional learner contracting COVID-19 from a patient was low. RT-PCR NP swabs are the gold standard for identifying COVID-19 infection; however, they are resource-intensive requiring physician supervision, clerical, nursing and technical staff. Moreover, this testing occurred at a time of extremely high demand on the laboratory services. Throughout the pandemic, it has been essential to allocate resources appropriately while adapting to variants of concern such as B.1.1.529 (omicron). As vaccines have become widely available in Canada, it is crucial to continually evaluate the use of non-pharmacological interventions such as RT-PCR, rapid antigen tests, symptom screening tools, contact tracing and masking to determine what interventions will keep health care professional learners’ and the community safe. Our data suggests that negligible asymptomatic infection occurred in this group during a time of mandatory masking, physical distancing and restrictions on gathering. While the negative results with the gold standard test were reassuring in the context of the events that were unfolding, NP- RT-PCR testing was very resource intense and this an important consideration for future decision making in this and future pandemics.
Limitations of this study include sampling bias, as health care professional students who participated in this study may have engaged in less risky behaviour than some of their peers that were not enrolled in this study. NP SARS-CoV-2 RT-PCR testing was mandatory for all medical students to engage with in-person learning requirements, but they did not have to participate in this study in order to obtain testing. RT-PCR NP testing was free and accessible to students through our research study and public health. Whereas the other Queen’s FHS’ programs did not require mandatory testing the asymptomatic infection of COVID-19 is not as thoroughly captured in these specific student populations.
Two other respiratory viruses, influenza A&B and HOPV, were also not identified. Infections with these viruses were at a historic low. This is likely due to the low rates of these viruses circulating in the general population as a result of increased public health safety measures such as increased hand-washing, physical distancing, mask use, decreased contacts and higher influenza vaccine coverage [11–14].
Future directions include evaluating the seropositivity of this group due to previous infection and vaccine-induced immunity, mental health outcomes, demographic and travel risks within this population.