This is a companion article to the feature, “Emerging Infectious Diseases in the Laboratory.”
By Sharon Andrews, MT(ASCP), MPH; Roberta Carey, PhD; Nancy E. Cornish, MD; Kristen Nordlund; and Anne Pollock, MT(ASCP)
To support patient care, clinical laboratories may need to perform routine laboratory testing, such as chemistry, hematology, or other laboratory testing. These laboratories can safely provide testing by strictly adhering to the blood-borne pathogens standard of the Occupational Safety and Health Administration, which is a well-established standard for protecting laboratory personnel from any known or unknown pathogens that are present in blood or body fluids.
By performing a site-specific assessment to identify risks of splashing, spraying, and aerosolization of infected specimens—and by mitigating these risks by implementing appropriate engineering controls and safety practices, and wearing appropriate personal protective equipment (PPE)—laboratory personnel can safely conduct routine diagnostic tests on patients under investigation for ebola virus disease or other potential infectious diseases.
We advise laboratories to restrict testing to closed systems in which the sample tube stays capped during testing, but still emphasize the need for a risk assessment to ensure that potential exposure risks are identified and mitigated with appropriate engineering controls, safety practices, and PPE.
Centrifugation can pose a risk of aerosolization. If centrifugation is necessary for testing, we recommend that it be restricted to a centrifuge that has sealed rotors.
If open test systems must be used, we caution laboratorians that uncapping of the tubes should be done under a Class II biosafety cabinet or behind a fixed Plexiglas 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 safety risks associated with the laboratory’s specific processes and procedures, including the potential for aerosolization, splashing, or spraying from the pipetting or other modules on the instrument; and for implementation of engineering controls, safety practices, and PPE to mitigate the identified risks.
Keep in mind that core clinical laboratories often have open-room designs housing many instruments and multiple specialties. Thus, risk may extend to workers present in the area who are not directly involved with the testing of a particular sample. Some facilities have chosen to limit this risk of exposure by establishing small, separate laboratories where testing on samples from suspected ebola patients can be performed.
US Centers for Disease Control and Prevention coauthors for this article include Sharon Andrews, MT(ASCP), MPH, health scientist in the global disease detection branch in the division of global health protection in the Center for Global Health; Nancy E. Cornish, MD, medical officer, and Anne Pollock, MT(ASCP), health scientist, in the division of laboratory programs, standards, and services in the Center for Surveillance, Epidemiology, and Laboratory Services; and Roberta Carey, PhD, distinguished consultant in the office of the director, and Kristen Nordlund, public affairs officer, in the National Center for Emerging and Zoonotic Infectious Diseases.