Laboratory Testing for Ebola

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How Ebola is Diagnosed in the Laboratory 

Ebolavirus can be detected in blood after the onset of symptoms. However, it may take up to three days after symptoms start for the virus to reach detectable levels. 

Polymerase chain reaction (PCR) is one of the most commonly used diagnostic methods because of its ability to detect low levels of virus.  

There are four species of Ebolavirus known to cause disease in humans. Among them, the Zaire ebolavirus has been the leading cause of infections. As a result, laboratory diagnostics have focused on identifying that species and testing is available in more than 200 laboratories in the United States. However diagnostic testing for Sudan ebolavirus, the species seen in the current outbreak in Uganda, is not as widespread. While federal agencies are working to increase testing capacity for the Sudan ebolavirus, it is currently limited to a handful of labs across the country.  

What To Do If Ebola is Suspected 

If your facility has a person under investigation (PUI) for a suspected Ebolavirus, contact your public health department for testing options and specific specimen information. (CDC, https://www.cdc.gov/infrastructure/contact/index.html, accessed 10/11/22)

Assess the Risks Prior to Specimen Collection 

If a person under investigation (PUI) meets the Ebolavirus testing criteria, minimize the risk to personnel by doing a risk assessment prior to specimen collection. (CDC, https://www.cdc.gov/viral-hemorrhagic-fevers/hcp/diagnosis-testing/index.html, 10/11/22)

• Do you have personal protective equipment (PPE)?

• Do you have all the collection supplies you need?

• Do you have personnel that are trained in collection procedures?

• Do you have or need a partner when collecting a specimen?

• Do you have a plan for waste generated from collection?

• Do you have specimen bags?

• Do you have EPA-approved disinfectant wipes available?

• Do you have safe donning/doffing procedures?

• Do you have a plan for PPE once it is doffed?

Preparing before you collect specimens can not only reduce risks for the patient and personnel, but it can also greatly reduce anxiety and/or fears. 

Collecting Clinical Specimens

While specimen type may vary, most PCR tests utilize whole blood collected in an EDTA tube (purple top). Always use plastic (not glass) collection tubes that do not contain heparin. Be sure to check with your testing facility prior to sending to ensure correct specimen source and tube type. 

Note: If the person under investigation’s (PUI’s) symptoms have been present for <3 days, a second specimen may be required and collected after 72 hours of symptom onset to definitively rule out Ebola. 

Shipping Clinical Specimens

Clinical specimens from PUIs being evaluated for Ebolavirus are considered Category A diagnostic specimens and must be packaged and shipped following specific regulations. Personnel shipping these specimens must be trained and certified to ship Category A substances. Check with your facility to determine whether there are personnel trained in Category A shipping. 

Managing and Testing Routine Clinical Specimens

While routine laboratory specimens suspected or confirmed to contain Ebolavirus can be managed safely in the laboratory, there are many considerations to take into account prior to implementing routine testing. The CDC has resources available to address risk assessment questions if routine laboratory tests are required while a person under investigation (PUI) is being cared for in your facility. (CDC, https://www.cdc.gov/viral-hemorrhagic-fevers/php/laboratories/guidance-on-performing-routine-diagnostic-testing-for-patients-with-suspected-vhfs-or-other.html?CDC_AAref_Val=https://www.cdc.gov/vhf/ebola/laboratory-personnel/safe-specimen-management.html#cdc_generic_section_9-risk-assessment-and-mitigation, accessed 10/11/22) NETEC has resources available to help address risk mitigation during laboratory testing. 

Resources for Health Care Workers

NETEC offers free training, resources, and consultation to help ensure that clinicians can safely and effectively care for patients infected with high consequence pathogens like Sudan ebolavirus.