“Ebola outbreak”: few phrases carry more weight in the infectious disease community. Since its discovery in 1976, different strains of Ebola virus have struck repeatedly across Africa, leaving devastated communities and persistent questions about transmission, treatment and response in its wake.
Four experts from the University of Florida Emerging Pathogens Institute gathered to address this specific Ebola strain and current outbreak, drawing on lessons from previous outbreaks in the Democratic Republic of Congo and examining it at a more microscopic level to understand how it operates.
What follows has been edited for length and clarity.
John Lednicky, Ph.D., is a research professor at the UF College of Public Health and Health Professions and a prolific EPI member. His current research focus areas are aerovirology, virus discovery, virus surveillance and influenza virus studies.
What is Ebola virus, and what makes this virus different from other viral strains?
The current outbreak is caused by the Bundibugyo virus strain, but the Ebola Zaire strain is responsible for most outbreaks in this region. Bundibugyo has had only three recorded outbreaks, including this one, since its discovery. These viruses are notorious for causing severe and often fatal hemorrhagic fevers, such as Ebola virus disease.
These viruses belong to the genus Orthoebolavirus, which are single-stranded, negative-sense RNA viruses in the family Filoviridae. Regarding “Filoviriudae,” ‘filo’ means filaments or sticks, since these viruses are often rod-shaped and sometimes curved, resembling a shepherd’s crook.
If there have been outbreaks of this strain before, why did it take so long to determine this outbreak to be an Ebola outbreak?
The region’s diagnostic tools include RT-PCR, meaning reverse transcriptase polymerase chain reaction. It uses RT to convert the RNA of RNA viruses into DNA for amplification by PCR. While RT-PCR is expected to detect all Orthoebolavirus strains, limited resources may compromise the thoroughness of testing. It’s also unclear whether the virus has mutated into a more harmful form, as full sequencing and comparisons with past outbreaks haven’t been available.
Soung Brice, Ph.D., is a postdoctoral associate at the UF College of Medicine. During the 2018 Eastern Ebola viral disease outbreak, also known as the 10th DRC Ebola outbreak, Brice was the leading UNICEF researcher for the Butembo sub-coordination. Toward the end of the 10th DRC Ebola outbreak, he was directly involved in operational research on COVID-19 and Ebola viral disease in the DRC’s Equateur province.
What did the data you collected during the 10th DRC Ebola outbreak teach you about what actually moves communities toward genuine engagement and response in public health?
The magic word is trust. To build trust, we approached the community to learn their perspective on the response activities and how to effectively repackage public health interventions. After carefully listening to community feedback and observing challenges with interventions such as contact tracing and vaccination, we took meaningful steps. We conducted quick, focused studies within the communities and confirmed the findings with them. Based on this shared understanding, we worked hand in hand with the community to develop actionable recommendations based on the Ebola response “pillars” of surveillance, prevention, infection control, communication and vaccination. We quickly learned that the people’s voices must always be heard; they may not always be backed by science, but including them in the process helped build trust and the successful implementation of the interventions.
Funeral and burial practices have historically been one of the primary drivers of Ebola transmission. How do you approach conversations with community and religious leaders about modifying these practices without harming a community’s sense of dignity and cultural identity?
We need to remember that the Ebola outbreak is temporary, but the community culture is permanent. We also need to ensure that trained teams properly handle confirmed deceased cases to reduce infectious contacts and future infections. The most important piece here is communicating this to the community in a way that leads to acceptance of the approach. During the 10th DRC Ebola outbreak, we used what we call “safe and dignified burials.”
When the response team processed the body of a confirmed Ebola case, a family member in personal protective equipment was directly involved in corpse preparation and decontamination. Mortuary bags, redesigned with transparent sections, allowed family members to see the face and mourn in a culturally appropriate way. The family representative was also informed of the attendance restrictions and conveyed them to the family. We reduced the risk of infectious contact and broke transmission chains while strictly adhering to cultural norms and values.
When a community is simultaneously dealing with hunger, displacement, and war, what does it take to mount a response that communities actually feel is there to help them?
In the Ituri context, the most efficient approach would be an integrated health response. The community should be involved in identifying and ranking the life-threatening conditions they are experiencing, based on their severity and urgency. It’s important to remember that, prior to this outbreak, people have been suffering and dying from health conditions other than Ebola, and still are. Community-based health interventions should not be limited to Ebola. For example, a comprehensive health package that includes nutritional kits, symptom recognition pamphlets, guidance on actions, case management and procedures will be more effective in addressing Ebola, malnutrition, malaria and vaccine-preventable diseases. Community involvement in mapping and addressing these health priorities is crucial for successful interventions, as they understand their community better than anyone else.
The Bundibugyo virus carries trauma for Ituri, DRC, specifically. As a researcher who worked in that region, how do you think the memory of that outbreak and the way the response was conducted are shaping how those living in the affected areas perceive health workers and institutions?
I will first start by reiterating my full support to the people of DRC, especially those affected by this outbreak. Looking at the memories of the past Ebola outbreak, we first have the sad memories of losing people we loved and cared about. But this sad part of the Ebola outbreak is somewhat alleviated by the fact that the population witnessed how, together with the response, we were able to control the outbreak and limit its impacts; it could have been worse without the response team. We must acknowledge that.
It’s true. Initially, we faced community non-compliance, indicating gaps in our approach. So, we reassessed the intervention with the community, listening and encouraging their full participation. These adjustments improved community appreciation and trust. After the 2018-2020 Ebola outbreak, COVID-19 emerged, and a new Ebola outbreak occurred in the DRC’s Equateur region. We applied lessons learned to address these outbreaks, and these efforts fostered positive perceptions of the response team.
Ira Longini, Ph.D., is currently working with the World Health Organization on the vaccine research and development blueprint for this strain of Ebola virus. Longini, an EPI member and professor at UF PHHP, specializes in the mathematical and statistical theory of epidemics. His research with the WHO helped develop the Ebola Zaire vaccine following the 2014/15 West African Ebola outbreak.
Unlike Ebola Zaire strains, there are currently no approved Bundibugyo virus-specific therapeutics or vaccines. What tools exist in the absence of approved countermeasures?
The only way to really control this kind of epidemic is through surveillance and containment. The name of the game is to find, isolate, treat and quarantine. The WHO has a program called MEURI, which is monitored emergency use of unregistered investigational interventions; it’s the compassionate use of experimental drugs and antivirals in situations like this. There is an experimental drug, obeldesivir, that can be used to treat active cases and possibly pre- and post-exposure prevention in cases of close contacts. It’s also possible that the Ebola Zaire vaccine might have some cross-protective effects for this strain, as shown in animal studies.
Initial cases in Bunia, DRC, tested negative for the more common Zaire strain of Ebola, which delayed identification of the Bundibugyo virus. What does this diagnostic gap tell us about the surveillance infrastructure that exists for less common Ebola species, and what would it take to fix it?
We need better diagnostics for the PCR test to detect this virus. Currently, diagnostics are improving with greater availability of accurate primers, enabling detection in the field. In 2018/20, a two-year ring vaccination effort targeted Ebola Zaire in the same areas. Despite the use of the highly efficacious rVSV vaccine in ring vaccination, about 3,500 cases and 2,800 deaths occurred. During that outbreak, we identified two effective monoclonal treatments through trials and the MEURI study. We need to do something similar now, but it feels like 2014 — large spread, no vaccines or therapeutics.
The high number of reported deaths and suspected cases, coupled with very poor surveillance in the affected region, suggests the outbreak is much larger than detected. How do modelers account for such uncertainty when advising governments on response, resources and border measures?
There are other ways to infer the size of an outbreak, and we did so with COVID-19 at the beginning of 2020. As we look at the populations where cases are imported — in this case, Uganda — and we know the movement rates roughly, we can model to infer the size of the outbreak by tracking where cases are imported into other countries.
J. Glenn Morris, M.D., M.P.H. & T.M., has worked in public health and pathogen-related fields for more than 40 years. As the founding director for the EPI, Morris has helped shape the creative vision behind a web of campus-wide projects to anticipate, understand and control the emergence of new, disease-causing microorganisms.
What is Ebola virus disease and what makes this disease different from other viral infections?
Ebola virus disease is the name of the condition caused by the virus, and it can be very serious. It has a high mortality rate, depending on the strain, and is easily transmitted. Late-stage symptoms include unexplained internal and external bleeding or bruising, confusion, irritability or aggression, shock and multi-organ failure.
In the early days of a patient’s illness, what does the diagnostic picture look like, and how do you avoid both missing an Ebola case in areas where other febrile illnesses are endemic?
That’s the problem. Compared to malaria and cholera, the more identifiable, severe symptoms, like bleeding, tend to occur later in the course. At the beginning, it may be difficult for physicians or medical personnel to clearly recognize that a patient has Ebola. Obviously, when you’re in an endemic setting, like at this point, everybody is very alert, but there’s no specific early diagnostic characteristic waving a red flag. Medical personnel often face high death rates because they treat patients without full protective gear, assuming the Ebola risk is low. The problem is balancing necessary caution with safety. The EPI has had a strong international presence, especially in the DRC, until recently. We are acutely aware of the socio-political and public health situation. Unfortunately, we have not been able to continue these field studies due to funding restrictions, but research into how these diseases affect this region is paramount to the EPI.
Written by: Sydney Burge