The Seroepidemiology of SARS-CoV-2 in Dental Practitioners: A Prospective Study

Jiahui (Madelaine) Li

Li, Jiahui (Madelaine)
Faculty / Advisor: Nightingale, Kira, Corby, Patricia, M
University of Pennsylvania School of Dental Medicine, Center for Clinical and Translational Research


This study was conducted to understand the rate of acquiring infection of SARS-CoV-2 among dental workers, determine risk factors that may influence the rate of infection, and evaluate the effectiveness of infection control procedures put in place at PDM to limit SARS-CoV-2 transmission.


In total, 109 subjects were recruited, including faculty, residents, dental students, hygienists, and dental assistants. All eligible subjects were required to be involved in direct patient treatment for at least 10 hours per week, practice only at clinics at which PDM infection control policy applied, and have never tested positive for an active or prior SARS-CoV-2 infection. At the baseline visit, subjects were asked to complete a questionnaire and provide information about demographics, medical history, work setting, symptoms, and exposure risks. At follow up visits scheduled every two months, new symptoms and exposure risks were updated. Blood samples were obtained at every visit to analyze the presence of SARS-CoV-2 IgG and IgM antibodies. Information from the baseline questionnaire, new symptoms, and exposure risks at each visit were used to establish correlations with antibody titer results. Seropositive results were excluded if they occurred after vaccination for SAR-CoV-2.


This study was terminated in January 2021 after the SARS-CoV-2 vaccine became available to PDM and data presented is from 09/2020 to 01/2021. Six subjects tested positive for antibodies. These six subjects were IgG positive indicating they had a past infection of SARS-CoV-2. Two of these subjects were also positive for IgM, which indicates a more recent infection. 4 DMD students tested positive (6.2%), 1 resident (6.7%), 1 faculty (5.3%) and 0 assistants/hygienists tested positive. All participants who tested positive for antibodies reported travelling out of state, (N=3), being exposed to a confirmed/suspected SARS-CoV-2 patient outside of the work setting (N=2), or both (N=1). No subjects who reported that they provided direct patient care to a diagnosed or suspected SARS-CoV-2 patient had positive antibody titers.


This study provides insights about the transmission rate of SARS-CoV-2 among dental workers in a dental school setting, and identifies certain risk factors, such as traveling, with a positive antibody titer. It also illustrates the efficacy of PDM infection control policy at preventing SARS-CoV-2 transmission.