The ongoing Coronavirus disease 2019 (COVID-2019) pandemic has created unprecedented challenges for communities, healthcare workers, and laboratory professionals looking to control the spread of SARS-CoV-2, the causative virus of COVID-2019. Despite the relatively novel nature of SARS-CoV-2, interim laboratory biosafety guidances issued by Centers from Disease Control (CDC) and the World Health Organization (WHO) provide clarity on several matters related to safe handling of samples within clinical and research laboratories. By following these recommended guidelines, laboratories can greatly limit risk to themselves and others.
Here are key considerations from the CDC and WHO interim guidelines.
“Q: What step(s) should my laboratory facility undergo prior to receiving COVID-19 samples?”
A: Laboratories expecting to receive COVID-19 samples should first consult their site’s Biosafety Officer or responsible Environmental Health & Safety Officer for guidance prior to receipt of any samples. Additionally, the CDC and WHO both recommend performing site-specific and activity-specific risk assessments involving areas and processes of/by a lab that will be impacted by suspected and confirmed samples of COVID-19. Although SARS-CoV-2 is a new virus, it does share similarities with other pathogenic viruses – as such, laboratories may already be prepared to handle COVID-19 samples without significant modifications to facilities and procedures.
“Q: What Biosafety Level (BSL) is recommended for laboratories handling suspected COVID-19 samples?”
A: The CDC recommends that clinical laboratories handling patient samples such as respiratory specimens, blood (and blood constituents), and urine practice Standard Precautions within a BSL-2 facility. Additionally, work involving full-length genomic RNA should also be carried out at BSL-2.
Activities involving high concentrations of live virus (e.g. propagation or isolation), or large volumes of infectious samples should be performed in no less than a BSL-3 environment.
Those seeking a full list of requirements for each biosafety level may reference definitions in the CDC’s freely available resource, Biosafety in Microbiological and Biomedical Laboratories (BMBL) 5th edition.
“Q: What type of laboratory containment enclosure is required to process COVID-19 samples?”
A: The CDC and WHO currently recommend that Class II Biosafety Cabinets (BSCs) be utilized any time a laboratory procedure has the potential to generate aerosols or droplets as result of vortexing, pipetting, centrifugation, or other techniques. Class II BSCs are an ideal choice for handling COVID-19 samples because they provide 3 levels of protection: personnel protection (the user), product protection (the sample), and environmental protection (the laboratory). Suspected COVID-19 samples that will be analyzed using rRT-PCR will benefit additionally from the ISO 5 HEPA filtered laminar airflow pattern generated within Class II BSCs. Class II, Type A2 or Type C1 BSCs are suitable and do not have a requirement for external ventilation. Class II, Type B2, which must be externally vented by design, are also acceptable.
Note: Any Class II BSC to be used for handling of COVID-19 samples (or any other use) should be tested and certified by a trained professional prior to use.
“Q: What laboratory disinfectants are recommended for use against SARS-CoV-2?”
A: Presently the CDC recommends utilizing disinfectants recognized on the Environmental Protection Agency’s (EPA) List N, of which all are approved for use against SARS-CoV-2. Many List N disinfectants contain hydrogen peroxide, alcohol, bleach, or quaternary ammonium constituents. Consult with the disinfectant manufacturer if unsure about the suitability of a particular agent against SARS-CoV-2.
“Q: What additional biosafety resources and guidances are available for laboratories handling SARS-CoV-2 virus and COVID-19 samples?”
ABSA International: https://absa.org/coronavirus/
Centers for Disease Control, Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Coronavirus Disease 2019 (COVID-19)
World Health Organization, Laboratory biosafety guidance related to the novel coronavirus (2019-nCoV)