How clinical laboratories can safely manage specimens from persons under investigation for Ebola virus disease.
Clinical laboratories may have many questions about how to safely manage laboratory specimens from patients under investigation (PUI) for Ebola virus disease (EVD). CDC recognizes that Ebola can cause a great deal of fear, but U.S. clinical laboratories have safety measures in place for other known (and more importantly, unknown) infectious diseases; these measures are critical to ensuring the safety of laboratory personnel when evaluating PUI for EVD.
According to the CDC, this guidance should be used as a supplement to CDC's document, "Interim Guidance for Specimen Collection, Transport, Testing, and Submission for Persons Under Investigation for Ebola Virus Disease (EVD) in the United States." www.cdc.gov/vhf/ebolaAicp/interimguidance-specimen-collection-submission- patients-suspected-infection-ebola.html.
U.S. clinical laboratories can safely handle specimens for EVD by following all required laboratory precautions and practices as specified in 29 CFR 1910.1030 for bloodborne pathogens.
Personnel who process and perform laboratory testing on specimens from a PUI for EVD should wear gloves, fluid-resistant or impermeable gowns, full face shield or goggles, and masks to cover all of the nose and mouth AND use a certified Class II biosafety cabinet or Plexiglass splash guard. If a certified Class II biosafety cabinet or Plexiglass splash guard is not available, a full face shield should be worn instead of goggles. Anyone collecting specimens from a patient should follow the procedures included in this guidance for transporting specimens through the healthcare facility and clean-up of spills.
PPE and equipment safety features should be used. Risk assessments should be conducted by each laboratory director, biosafety officer, and other responsible personnel to determine the potential for sprays, splashes, or aerosols generated from laboratory procedures. OSHA's Hierarchy of Controls should be followed for adjusting work practices, safety equipment controls, and Personal Protective Equipment (PPE) requirements as needed to protect the laboratorian's skin, eyes, and mucous membranes. Laboratory personnel should keep in mind that a patient may have an infectious disease other than EVD which may require additional PPE.
When clinical laboratorians are manipulating primary patient specimens in the laboratory, staff should use an appropriate combination of PPE and physical containment devices to protect their mouth, nose, eyes and bare skin from coming into contact with patient specimens. Additionally, clinical laboratorians should use manufacturer-installed safety features for instruments that reduce the likelihood of exposure and to ensure additional protection.
Some laboratory procedures (e.g., centrifugation) have the potential to produce aerosols or small droplets. If such procedures must be performed, physical containment devices such as sealed centrifuge rotors or centrifuge safety cups should be used, along with PPE as indicated above.
CDC's recommendations to U.S. clinical laboratories for safe management of diagnostic specimens from PUI for EVD are consistent with recommendations for other known infectious diseases that are transmitted through blood or body fluids, such as HTV and hepatitis. If clinical laboratories decide to add additional precautions, they should provide training and have staff practice these procedures and use the PPE in advance. Consistency of these planned procedures is important to protect personnel. Using available PPE and procedures that meet CDC guidelines and are familiar to clinical laboratorians will allow them to safely manage specimens from a PUI for EVD.
Decontamination. The outside of blood collection tubes can be wiped off with an appropriate disinfectant as described in "Interim Guidance for Environmental Infection Control in Hospitals for Ebola Virus" (www.cdc.gov/vhf/ebola/hcp/environmental-infection-control-in-hospitals. html). The basic principles for blood or body substance spill management are outlined in the United States Occupational Safety and Health Administration (OSHA) bloodborne pathogens standard (29 CFR 1910.1030). Before any spill clean up is initiated, ensure that staff are trained and wear recommended PPE including, at a minimum, disposable gloves, gown (fluid resistant/ impermeable), eye protection (goggles or face shield), and facemask to protect against direct skin and mucous membrane exposure of cleaning chemicals, contamination, and splashes or spatters during environmental cleaning and disinfection activities. CDC guidelines recommend removal of bulk spill matter, cleaning the site, and then disinfecting the site with a disinfectant effective against the potential agent. For large spills, a chemical disinfectant with sufficient potency is needed to overcome the tendency of proteins in blood and other body substances to neutralize the disinfectant's active ingredient. An EPA-registered hospital disinfectant with label claims for non-enveloped viruses (e.g., norovirus, rotavims, adenovirus, poliovirus) and instructions for cleaning and decontaminating surfaces or objects soiled with blood or body fluids should be used according to those instructions.
Transporting specimens from PUI for EVD within the hospital/institution. In compliance with 29 CFR 1910.1030, specimens should be placed in a durable, leak-proof secondary container for transport within a facility. To reduce the risk of breakage or leaks, do not use any pneumatic tube system (automated or vacuum specimen delivery system) for transporting specimens from PUI for EVD. If the pneumatic tube system was inadvertently used for transport and the specimen collection tube was damaged, follow the manufacturer's instructions for decontamination or contact the CDC EOC for consultation at 770-488-7100.
Diagnostic testing for EVD. Several diagnostic tests are available at CDC for detection of EVD. Evidence of acute infection will be verified using a real-time RT-PCR assay (CDC test directory code CDC -10309 Ebola Identification) in a CDC CLIA-certified laboratory. The actual presence of infectious Ebola virus in a clinical sample will be confirmed by isolating virus in culture. Viral isolation must be done in a laboratory that meets appropriate biosafety level--4 guidelines for safely culturing this virus. Serologic testing for IgM and IgG antibodies will be completed for certain specimens and to monitor the immune response in confirmed EVD patients (#CDC-10310 Ebola Serology).
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|Title Annotation:||CDC update|
|Publication:||Medical Laboratory Observer|
|Date:||Nov 1, 2014|
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