At this point in time, there is limited evidence of transmission of SARS-CoV-2 from people who are asymptomatic and never develop symptoms. Most evidence from other respiratory viruses suggest that transmission events predominantly occur with the peak of symptoms (highest fever, levels of coughing, sneezing and rhinorrhea).
During the development of the COVID-19 Return to Work Guidelines for the Oral Health Professions of Nova Scotia, there was a great deal of thought and research put into answering this very question. Input was received from Nova Scotia’s Chief Medical Officer of Health, infectious disease experts, Occupational Health and Safety, and Public Health.
To summarize, there is minimal data on cultivatable viral loads with SARS-CoV-2 in asymptomatic, pre-symptomatic, and pauci-symptomatic infection, and on the proportion of transmission which may be attributed to these categories. The risk mitigating (not eliminating) measures included in the COVID-19 Return to Work Guidelines for the Oral Health Professions of Nova Scotia, including screening protocols, enhanced infection control, and additional PPE requirements have been implemented to reduce the potential for transmission form the asymptomatic carrier. These steps are intended to keep the public and Dental Healthcare Providers (DHCPs) safe.