Update on CDC Guidelines on Ebola Specimen Handling + Lab Testing

In response to several reader questions on the CDC post on safe handling of Ebola and recommended lab procedures, the CDC got back to us with this update:

In the Ebola guidance for healthcare workers and specifically for Specimen Handling for Routine Laboratory Testing  of  persons under investigation (PUI) for Ebola disease , CDC reminds all laboratory personnel to consider all blood and body fluids as potentially infectious.  The guidance further informs laboratory personnel that strict adherence to the OSHA bloodborne pathogen regulations and Standard Precautions protects laboratory workers from bloodborne pathogens, including Ebola. In this guidance, emphasis is placed on the OSHA regulation’s requirement for performance of site-specific risk assessments.  These assessments should consider the path of the sample throughout the laboratory, including all work processes and procedures, to identify potential exposure risks and to mitigate the risks by implementing engineering controls, administrative controls (including work practices), and appropriate PPE to protect laboratory personnel.  Implementation of these recommendations requires that there is designated staff that is trained, competent, and confident in performing risk assessments within their laboratories.

Many hospitals feel that the preferred method of clinical laboratory testing is to restrict testing to point of care instruments, using dedicated testing staff that is trained and familiar with the instruments and techniques, safety practices, and PPE.  However, it is necessary to refer to the Intended Use statement located in the manufacturer’s package insert to make sure the instrument does not exclude testing on critically ill patients.  It is the responsibility of the laboratory director to assure that the point of care instruments provide reliable results to support the care of critically ill patients.   Alternately, testing can safely be done in the main clinical laboratory if a risk assessment has been performed of all laboratory work processes and procedures, along with steps taken to mitigate the risks.

We have had many questions about whether it is safe to test using open instrumentation (you have to decap the tube with sample before loading onto the instrument).  We advise, if at all possible, to restrict testing to closed systems, but still, we  emphasize the need for risk assessment to assure the potential for exposure is identified and mitigated with appropriate PPE, work practices, and engineering controls.

If open test systems are used, we caution laboratorians that decapping of the tubes should be done under a Class II Biosafety Cabinet or behind a fixed plexiglass shield while wearing a full face shield and mask.  The specimen should be placed in a rigid container with lid to move to the site of the instrument for testing.  Again, we strongly emphasize the need for an assessment to identify risks of these processes and procedures, including the potential for aerosolization, splashing, or spraying from the pipetting or other modules on the instrument, and implement practices, PPE, and engineering controls to mitigate the risk.  Keep in mind that clinical laboratories often have open room designs, and risk may extend to workers that may not be directly involved with testing a particular sample, requiring broader use of PPE.

Centrifugation can pose a risk of aerosolization.  If centrifugation is necessary for testing, we recommend that it be restricted to use of a centrifuge that has sealed rotors; otherwise allow the sample to sit until components are separated.

For decontamination of laboratory instruments and equipment, the decontamination protocols appropriate for enveloped viruses such as HIV, influenza, or hepatitis C, is also effective against Ebola.  Follow the manufacturer’s instructions provided in the operator’s manual for cleaning the instrument and check to see what the manufacturer recommends when taking the equipment out of commission or getting it ready for repairs. CDC and manufacturers are aware of the challenges laboratorians and their institutions face when these instructions are not provided in the manuals.  Because some protocols may be specific to the equipment, they are discussing how best to respond to these concerns.

For links to additional guidance, see:







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1 reply »

  1. If you advise in this blog post restriction of testing to closed systems (third paragraph), why do I not see this in any of the guidelines posted on the CDC website?

    Your points in your fourth paragraph are well taken, that risk assessments need to be done. This has been reflected on the CDC website, but not to the detail you describe here. With increasing use of open and random access systems, and open room designs, why are not these details reflected on the CDC website?