Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Middle East Respiratory Syndrome Coronavirus (MERS-CoV)
To date, little is known about pathogenic potential and transmission dynamics of Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Until more information becomes available, precautions should be taken in collecting and handling specimens that may contain MERS-CoV.
Timely communication between clinical and laboratory staff is essential to minimize the risk incurred in handling specimens from patients with possible MERS-CoV infection. Such specimens should be labeled accordingly, and the laboratory should be alerted to ensure proper specimen handling. General and specific biosafety guidelines for handling MERS-CoV specimens are provided below.
For additional detailed instructions please refer to the following:
General Guidelines (for working with potentially infectious materials)
Laboratory workers should wear personal protective equipment (PPE) which includes disposable gloves, laboratory coat/gown, mask, and eye protection when handling potentially infectious specimens.
Acceptable methods of respiratory protection include: a properly fit-tested, NIOSH-approved filter respirator (N-95 or higher level) or a powered air-purifying respirator (PAPR) equipped with high-efficiency particulate air (HEPA) filters. Accurate fit-testing is a key component of effective respirator use. This includes training, fit-testing, and fit-checking to ensure appropriate respiratory selection and use. To be effective, respirators must provide a proper sealing surface on the wearer’s face. Personnel who cannot wear fitted respirators because of facial hair or other fit limitations should wear loose-fitting hooded or helmeted PAPRs. See detailed information on a respiratory protection program
Any procedure with the potential to generate fine-particulate aerosols (e.g., vortexing or sonication of specimens in an open tube) should be performed in a Class II Biological Safety Cabinet (BSC). Appropriate physical containment devices (e.g., centrifuge safety buckets; sealed rotors) should be used for centrifugation. Ideally, rotors and buckets should be loaded and unloaded in a BSC.
Perform any procedures outside a BSC in a manner that minimizes the risk of exposure to an inadvertent sample release.
After specimens are processed, decontaminate work surfaces and equipment with appropriate disinfectants. Use any EPA-registered hospital disinfectant. Follow manufacturer's recommendations for use-dilution (i.e., concentration), contact time, and care in handling.
All disposable waste should be autoclaved.
The following activities may be performed in BSL-2 facilities using standard BSL-2 work practices:
- Pathologic examination and processing of formalin-fixed or otherwise inactivated tissues
- Molecular analysis of extracted nucleic acid preparations
- Electron microscopic studies with glutaraldehyde-fixed grids
- Routine examination of bacterial and mycotic cultures
- Routine staining and microscopic analysis of fixed smears
- Final packaging of specimens for transport to diagnostic laboratories for additional testing. Specimens should already be in a sealed, decontaminated primary container.
- Inactivated specimens (e.g., specimens in nucleic acid extraction buffer)
The following activities involving manipulation of potentially infected specimens should be performed as above and in a Class II BSC:
- Aliquoting and/or diluting specimens
- Inoculating bacterial or mycological culture media
- Performing diagnostic tests that do not involve propagation of viral agents in vitro or in vivo
- Nucleic acid extraction procedures involving potentially infected specimens
- Preparation and chemical- or heat-fixing of smears for microscopic analysis
The following activities must be performed in a BSL-3 facility using BSL-3 work practices:
- MERS-CoV propagation in cell culture
- Initial characterization of viral agents recovered in cultures of MERS-CoV specimens
The following activities must be performed in Animal BSL-3 facilities using Animal BSL-3 work practices:
- Inoculation of animals for potential recovery of virus from MERS-CoV samples
- Protocols involving animal inoculation for characterization of putative MERS-CoV agents
Packing, Shipping and Transport
Packaging, shipping, and transport of specimens from suspect cases of MERS-CoV infection must follow the current edition of the International Air Transport Association (IATA) Dangerous Goods Regulations