Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) – Version 2
Summary of Changes in Version 2
This is an updated version of the interim guidance document issued by the Centers for Disease Control and Prevention (CDC) on May 29, 2014. CDC has revised the interim guidance based on comments received from public health partners, healthcare providers, laboratories, professional organizations and others. CDC will continue to update the document as necessary to incorporate new information that increases our understanding of MERS-CoV. Updates:
- Added a section titled “Clinical Laboratory Testing” to describe recommendations when handling potential MERS-CoV specimens in the clinical laboratory setting.
- Expanded the "Packing, Shipping and Transport" section to include updated and useful documents.
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:
- Biosafety in Microbiological and Biomedical Laboratories (BMBL) - Fifth Edition
- Laboratory Biosafety Manual - Third Edition
- 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings [225 pages, 1.83MB]
General Guidelines (for working with potentially infectious materials)
Laboratory workers should wear personal protective equipment (PPE) which includes disposable gloves, laboratory coat/gown, respirator, and eye protection when handling potentially infectious specimens.
Acceptable respiratory protection devices include: a properly fit-tested, NIOSH-approved filtering facepiece 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 a respiratory protection program (RPP) and will assist with effective respirator use. An RPP includes medical clearance, 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
Clinical Laboratory Testing
Clinical laboratories performing routine hematology, urinalysis, and clinical chemistry studies, and microbiology laboratories performing diagnostic tests on serum, blood, or urine specimens should follow standard laboratory practices, including Standard Precautions[1.83 MB, 225 pages], when handling potential MERS-CoV specimens.
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.
Follow shipping regulations for UN 3373 Biological Substance, Category B when sending potential MERS-CoV specimens.
- Packaging Checklist, see Category B [1 page] Saf-T-Pak
- Packing Instructions 650 for UN 3373 [4 pages]
- Labels for UN 3373
- When using cold pack [1 page] — Include the name and telephone number of the person who will be available during normal business hours who knows the content of the shipment (can be someone at CDC). Place the label on one side of the box and cover the label completely with clear tape (do not tape just the edges of the label).
- When using dry ice [1 page] — Include the name and telephone number of the person who will be available during normal business hours who knows the content of the shipment (can be someone at CDC). Place the label on one side of the box and cover the label completely with clear tape (do not tape just the edges of the label).
- Schematic for packaging, UN 3373 Category B [1 page]