We have been getting many questions from clients on appropriate precautions to take when working with COVID-19 positive samples in the lab. The World Organization (WHO), the Centers for Disease Control and Prevention (CDC), the Public Health Agency of Canada (PHAC), and the American Biological Safety Association (ABSA) have all published extremely informative guidance on this topic:
The information is consistent among these agencies and all stress the importance of starting with a risk assessment. This includes a site and protocol-specific assessment of the procedures to be performed, the identification of the hazards of the processes and procedures, an evaluation of the laboratory facility and equipment, as well as an assessment of available resources including personal protective equipment (PPE).
Coronaviruses generally infect the upper or lower respiratory tract, therefore work with respiratory specimens poses the highest risk. However, the virus has also been found in fecal samples, and although less common, shedding of the virus into plasma or serum can occur and blood samples from some COVID-19 patients have tested positive. Therefore, work with human blood from COVID-19 positive individuals can pose an exposure risk.
Depending on the risk assessment, working in a BL2 laboratory using enhanced safety practices is generally considered to be appropriate for work with all samples from individuals who have tested positive for COVID-19. The specific enhanced practices that are appropriate will be based on the outcome of the risk assessment and may include the use of additional PPE such as impervious gowns, double gloves, a face shield, surgical mask (blood), N95 respirator (respiratory secretions), and goggles. In addition, all procedures must be done in a biological safety cabinet (BSC). Other enhanced procedures may include posting of the work area and more frequent decontamination procedures.
Training is also a key component in ensuring worker safety. Training specific to the protocol is critical as well as training related to the enhanced practices required that includes competency in donning and doffing PPE and specific training on the use of surgical masks and N95 respirators.
For additional information on best practices for working with COVID-19 positive samples in your laboratory and for assistance in conducting a risk assessment for the work your company will be conducting, please email firstname.lastname@example.org.