PLEASE NOTE: For the most recent updates on this topic please refer to the Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Coronavirus Disease 2019 (COVID) on the CDC website.
During the COVID-19 pandemic and health care emergency, laboratories will continue to provide services essential for patient care. As a community rendering health care services, safe practice, avoiding/limiting high-risk situations and protecting health care workers is crucial. Therefore, as in other specialties, it may be necessary to modify procedures for specimen handling, prioritize essential services and discourage elective procedures.
Any laboratory employee who feels unwell, especially with fever and respiratory symptoms should not report to work, inform the laboratory supervisor, and seek advice from a health care provider. Employees should communicate both positive and negative results of COVID testing to their supervisor and local occupational health service. All laboratory employees must follow risk-reducing practices such as social distancing and hand hygiene. Therefore, crowding in the laboratory must be reduced by avoiding in-person laboratory meetings, in-person instructions, conferences, and case discussions.
Laboratories may experience a decrease in case volume due to a reduction in elective procedures. Laboratories may need to utilize this opportunity to modify schedules and shifts, stagger activities and breaks, keep only essential staff in the laboratory at any given time, and establish spatial distancing between workers, as required. Emergency plans should be clearly outlined in the event one or more individuals are ill or if there is a need to send a group of employees into quarantine. Alternate leadership in the laboratory should be designated.
Cytopathology services remain important in providing diagnoses for all types of patients. For example, in patients suspected or known to be positive for COVID-19, the cytology test can be used to help determine co-existing disease processes.
As a result, the following guidance applies to cytopreparatory techniques and specimen processing
- All personnel in the cytology laboratory should wear appropriate PPE prior to handling any specimen. PPE includes gloves, surgical masks, water resistant gown and eye protection (goggles or face shield) while processing specimens in a Class II Biosafety Cabinet (BSC). When a Class II BSC is not available or when facing patients with suspected or known positive COVID-19, it is recommended to use an N95 or PAPR mask instead of a surgical mask.
Submitted Specimen Processing
- A review of patient history by a member of the cytopathology team prior to initiating cytopreparation is suggested and may help identify risk factors for COVID-19. Alternatively, laboratories may want to consider all respiratory specimens as high-risk and manage accordingly.
- A laboratory can adapt the risk-factors list as determined by the clinical team or reference organizations like WHO.
- All high-risk specimens should be processed under a Class II biosafety cabinet (BSC) using universal precautions.
- All respiratory specimens such as bronchioalveolar lavages, bronchial brushings, sputum, pleural fluids, EBUS-guided FNAs, touch imprint slides from lung core biopsies, and any specimen from suspected or known COVID-19 patients should be considered high-risk specimens.
- It is best to batch high-risk specimens for processing by one technician/cytotechnologist, preferably using a separate station, if available.
- All cytopreparatory steps of high-risk specimens that can lead to aerosol/droplet formation, including opening of containers, removing tube caps, blending, vigorous shaking or mixing, vortexing, pipetting, aliquoting, diluting or centrifugation of fluids and discarding supernatant including loading and unloading centrifuge rotors and cups should be performed in a Class II BSC.
- At the completion of high-risk specimen processing, the prep station/hood should be decontaminated using standard laboratory protocols.
- Formalin or alcohol solutions with over 70% alcohol are considered effective to destroy this virus.
- Fixatives with weaker alcohol concentration are NOT effective at inactivating the virus.
- Staining should be performed according to established laboratory protocols for Papanicolaou-stained slides. When staining air-dried modified Giemsa stained slides, ensure that the fixation (first) step is adjusted to a length of 1 minute.
- Fixative used for these high-risk cases should be discarded daily.
- Disposal of high-risk specimens should follow standard laboratory procedures for specimens that might contain other respiratory pathogens.
- In addition to decontaminating benches and prep stations, decontamination of all work surfaces including computer keyboards, phones, and microscopes should be performed multiple times per day if possible, using EPA approved disinfectant solutions, wipes, towelettes or sprays.
Fine Needle Aspirations (fna) Procedures and Rapid Onsite Evaluations (rose)
- FNA requests should be limited to cases where a diagnosis rendered by the pathologist will effect a change in the patient interim or final management. Elective cases should be rescheduled or temporarily suspended.
- FNA on suspected or known COVID-19 cases should be discouraged/avoided where possible and performed only when essential to the medical management of the patient.
- When performing an FNA or Rapid-On-Site -Evaluation (ROSE), a complete history should be obtained by a member of the cytopathology team prior to initiating the procedure to determine risk factors for COVID-19.
- Performance of the FNA should be limited to essential members, such as the attending performing the FNA and the fellow or resident on service.
- Rapid-on-site-evaluation (ROSE) should be evaluated for patient need and personnel safety prior to performing.
- In the event the request is for ROSE only, the number of individuals involved in any step should be limited to essential members (cytotechnologist and pathologist or pathologist and fellow/resident).
- When performing ROSE any steps that may generate aerosols or droplets such as expelling aspirates from the needle or syringe, smearing the aspirated material, and air-drying or heat drying the smear by agitating the smears should be minimized.
- Air-drying or heat drying of smears is best performed under Class II Biosafety Cabinets (BSC).
- If an FNA or ROSE is performed, all staff involved should wear appropriate PPE (as above) and follow universal precautions.
- Laboratory processing should follow the recommendations detailed above.
- Information for laboratories https://www.cdc.gov/coronavirus/2019-nCoV/lab/
- Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Coronavirus Disease 2019 (COVID-19) https://www.cdc.gov/coronavirus/2019-nCoV/lab/lab-biosafety-guidelines.html
- Stefan E.Pambuccian MD, MIAC The COVID-19 pandemic: Implications for the cytology laboratory. JASC. https://doi.org/10.1016/j.jasc.2020.03.001
- Anthony F. Henwood (2020) Coronavirus disinfection in histopathology, Journal of Histotechnology, DOI: 10.1080/01478885.2020.1734718