Risk of SARS-CoV-2 transmission following exposure during dental treatment – A national cohort study

OBJECTIVES: Health care workers are at an increased risk of SARS – CoV-2 transmission. The risk of infection for dental teams is assumed to be high, due to work settings, proximity to mouth, exposure to saliva and aerosols. There is a lack of evidence that quantifies the risk of SARS-CoV-2 transmission for dental patients and staff. Our objective was to assess SARS-CoV-2 transmission risk for dental staff members (DSMs) and patients following exposure in dental clinics during the second wave of the pandemic in Israel. METHODS: The study analyzed new positive SARS-CoV-2 cases following exposures in dental clinics from May to September 2020. Two data sources were used: case report forms (CRFs) and epidemiological investigations. CRFs were developed by the MoH and distributed to dental clinics to identify DSMs exposed to SARS-CoV-2 positive patients, and patients exposed to positive DSMs. SARS-CoV-2 status was diagnosed using MoH approved tests in certified laboratories and verified against the national COVID-19 database. Statistical analysis on a non-identified basis was performed. The population incidence and dental setting transmission rates were calculated for the study period with 95% Confidence Intervals. RESULTS: Following 962 reported exposures of DSMs to 508 SARS-CoV-2 positive patients, 7 DSMs were SARS – CoV-2 positive with a 0.7% cumulative transmission rate. Following 507 reported exposures by 43 SARS-CoV-2 positive DSMs, 3 patients were SARS – CoV-2 positive, with a 0.6% cumulative transmission rate. During the study period, the SARS-CoV-2 incidence rate in dental clinics was significantly lower when compared to the population. CONCLUSIONS: The transmission rate of SARS-CoV-2 in dental settings was very low for both patients and DSMs. CLINICAL SIGNIFICANCE: Our results suggest that routine dental care could be safely provided during the pandemic. Continuous monitoring should be performed due to the emergence of new variants and the vaccination programs.