Ebola virus disease (EVD), commonly referred to solely as Ebola, is a rare and serious illness caused by one of several virus species within the genus Ebolavirus. Four species cause EVD in humans:
- Bundibuygo ebolavirus
- Sudan ebolavirus
- Tai Forest ebolavirus
- Zaire ebolavirus
Zaire ebolavirus is the most common and deadliest strain, responsible for the most outbreaks. EVD is a viral hemorrhagic fever and while case fatality rates have varied significantly, the average fatality rate is approximately 50%. However, when EVD is caused by Zaire ebolavirus, the fatality rate is estimated to be 70-90%. Ebola is transmitted through contact with infected bodily fluids, such as blood, feces, urine and saliva.
Ebola was first identified in 1976 during two simultaneous outbreaks in what are now the Democratic Republic of Congo (formerly Zaire) and South Sudan (formerly Sudan). More than 30 outbreaks of varying sizes have occurred since the virus was identified, with the vast majority of cases in West and sub-Saharan Africa.
APHL works both domestically and internationally to strengthen national laboratory systems to prepare for and respond to Ebola as well as other highly infectious disease threats. In addition to US public health laboratories, APHL works closely with the US CDC and the African Society for Laboratory Medicine (ASLM) to develop guidance, implement training and provide necessary support for laboratories to perform safe, high quality and efficient testing.
2022 Ebola Outbreak in Uganda
On September 20, 2022, Ugandan health authorities declared an outbreak of Ebola. The Uganda Virus Research Institute identified Sudan ebolavirus, also known as Ebola Sudan virus, as the causative pathogen of the outbreak which was the sixth Ebola outbreak in Uganda. The outbreak spread to nine districts and was declared overon January 11, 2023.
Outbreaks caused by Sudan ebolavirus are relatively rare. As such, there is no FDA approved or cleared assay for the detection of this species. However, the BioFire FilmArray NGDS Warrior Panel received FDA Emergency Use Authorization (EUA) in 2022. The panel can detect each Ebola species alongside Marburg virus, Bacillus anthracis, Coxiella burnetii, Francisella tularensis and Yersinia pestis in approximately one hour. Currently, the Warrior Panel is the only assay available to detect the Ebola Sudan Virus. As of mid-October 2022, nine laboratories within the Laboratory Response Network (LRN) have validated the panel and 12 additional laboratories are working with the CDC to also validate the panel.
Current Public Health Laboratory Testing Capability
Nine public health laboratories can currently conduct testing for the Ebola Sudan virus using the BioFire FilmArray Warrior Panel, which has received Emergency Use Authorization from the FDA. The panel can detect each Ebola species and is the only assay available to detect the Ebola Sudan Virus as of October 2022. The CDC is working with 12 additional laboratories to validate the panel as well.
Over 55 US public health laboratories can conduct testing for the Ebola Zaire virus using real-time reverse transcription polymerase chain reaction (rRT-PCR) tests deployed through the Laboratory Response Network.
Previous APHL Ebola Response Efforts
2018 Strengthening Laboratory Response in Sierra Leone
In Sierra Leone, APHL worked through 2018 to strengthen laboratory capacity and renovate the central laboratory. APHL-ASLM consultant Isatta Wurie, PhD, developed laboratory SOPs, supported implementation of a specimen referral system and implemented quality assurance practices at mobile testing centers run by donor nations. In addition, she developed a unified laboratory implementation plan to enable international aid workers to quickly identify how to support a single, integrated strategy for delivery of laboratory services.
APHL also assisted ASLM and the African Public Health Laboratory Network to:
Improve surveillance, communications, coordination and information sharing to enable quick response to emerging disease threats
Implement data repositories for capacity and capability mapping of member laboratories
Ensure access to specialized testing capacity made available across the network
Coordinate action on new global and regional policy priorities
Collaborate for research initiatives and share relevant data
Facilitate cross-training and assessments to raise all laboratories to standardized levels of capacity and readiness
Identify new resource opportunities
2014-2015 APHL Ebola Response
During the height of the Ebola response in 2014-2015, APHL provided situational updates and technical assistance to public health laboratories. The association developed a template to assist laboratories in conducting risk assessments of their facilities and other laboratory guidance documents for clinical and public health laboratories. In addition, APHL worked with state and local public health laboratories to prepare them to conduct Ebola testing and to respond to questions from clinical laboratories in their jurisdictions.
Outside the US, APHL worked with CDC and the African Society for Laboratory Medicine (ASLM) to stand up the African Public Health Laboratory Network and explore ways to build laboratory capacity on the continent. APHL facilitated a training on testing for the Ebola Zaire virus at the ASLM meeting in Cape Town in 2014 and collaborated with ASLM to develop a webpage and African Public Health Laboratories Network Listserv to share information related to the Ebola outbreak.