The 2018/19 Ebola epidemic the Democratic Republic of the Congo (DRC): epidemiology, outbreak control, and conflict

Ebola Virus Disease Outbreaks: Lessons Learned From Past and Facing Future Challenges

INTRODUCTION

The purpose of this review is to examine African Ebola outbreaks from their first discovery to the present, to determine how the medical and public health response has changed and identify the causes for those changes. We sought to describe what is now known about the epidemiology and spread of Ebola virus disease (EVD) from the significant outbreaks that have occurred and outbreak control methods applied under often challenging circumstances. Given the substantial role that the U.S. Government and the U.S. DoD have played in the 2014 to 2016 West African Ebola outbreak, the role of the DoD and the U.S. African Command in controlling EVD is described.

MATERIALS AND METHODS

A descriptive method design was used to collect and analyze all available Ebola outbreak literature using the PubMed database. An initial literature search was conducted by searching for, obtaining, and reading original source articles on all major global Ebola outbreaks. To conduct a focused search, we used initial search terms "Ebola outbreak," "Ebola virus disease," "Ebola response," "Ebola countermeasures," and also included each country's name where Ebola cases are known to have occurred. From the 4,673 unique articles obtained from this search and subsequent article title review, 307 articles were identified for potential inclusion. Following abstract and article review, 45 original source articles were used to compile the history of significant Ebola outbreaks. From this compilation, articles focused on each respective subsection of this review to delineate and describe the history of EVD and response, identifying fundamental changes, were obtained and incorporated.

RESULTS

We present known Ebola virus and disease attributes, including a general description, seasonality and location, transmission capacity, clinical symptoms, surveillance, virology, historical EVD outbreaks and response, international support for Ebola outbreak response, U.S. DoD support, medical countermeasures supporting outbreak response, remaining gaps to include policy limitations, regional instability, climate change, migration, and urbanization, public health education and infrastructure, and virus persistence and public awareness.

CONCLUSIONS

The health and societal impacts of EVD on Africa has been far-reaching, with about 35,000 cases and over 15,000 deaths, with small numbers of cases spreading globally. However, the history of combatting EVD reveals that there is considerable hope for African nations to quickly and successfully respond to Ebola outbreaks, through use of endemic resources including Africa CDC and African Partner Outbreak Response Alliance and the U.S. African Command with greater DoD reachback. Although there remains much to be learned about the Ebola virus and EVD including whether the potential for novel strains to become deadly emerging infections, invaluable vaccines, antivirals, and public health measures are now part of the resources that can be used to combat this disease.

Ebola virus disease in children: epidemiology, pathogenesis, management, and prevention

Ebola disease is a severe disease with extremely high case-fatality rates ranging from 28-100%. Observations made during the 2013-2016 West African epidemic improved our understanding of the clinical course of Ebola disease and accelerated the study of therapeutic and preventative strategies. The epidemic also highlighted the unique challenges associated with providing optimal care for children during Ebola disease outbreaks. In this review, we outline current understanding of Ebola disease epidemiology, pathogenesis, management, and prevention, highlighting data pertinent to the care of children. IMPACT: In this review, we summarize recent advancements in our understanding of Ebola disease epidemiology, clinical presentation, and therapeutic and preventative strategies. We highlight recent data pertinent to the care of children and pregnant women and identify research gaps for this important emerging viral infection in children.

Perspectives on Advancing Countermeasures for Filovirus Disease: Report From a Multisector Meeting

Although there are now approved treatments and vaccines for Ebola virus disease, the case fatality rate remains unacceptably high even when patients are treated with the newly approved therapeutics. Furthermore, these countermeasures are not expected to be effective against disease caused by other filoviruses. A meeting of subject-matter experts was held during the 10th International Filovirus Symposium to discuss strategies to address these gaps. Several investigational therapeutics, vaccine candidates, and combination strategies were presented. The greatest challenge was identified to be the implementation of well-designed clinical trials of safety and efficacy during filovirus disease outbreaks. Preparing for this will require agreed-upon common protocols for trials intended to bridge multiple outbreaks across all at-risk countries. A multinational research consortium including at-risk countries would be an ideal mechanism to negotiate agreement on protocol design and coordinate preparation. Discussion participants recommended a follow-up meeting be held in Africa to establish such a consortium.

Epidemiology of Ebolaviruses from an Etiological Perspective

Since the inception of the ebolavirus in 1976, 32 outbreaks have resulted in nearly 15,350 deaths in more than ten countries of the African continent. In the last decade, the largest (2013-2016) and second largest (2018-2020) ebolavirus outbreaks have occurred in West Africa (mainly Guinea, Liberia, and Sierra Leone) and the Democratic Republic of the Congo, respectively. The 2013-2016 outbreak indicated an alarming geographical spread of the virus and was the first to qualify as an epidemic. Hence, it is imperative to halt ebolavirus progression and develop effective countermeasures. Despite several research efforts, ebolaviruses' natural hosts and secondary reservoirs still elude the scientific world. The primary source responsible for infecting the index case is also unknown for most outbreaks. In this review, we summarize the history of ebolavirus outbreaks with a focus on etiology, natural hosts, zoonotic reservoirs, and transmission mechanisms. We also discuss the reasons why the African continent is the most affected region and identify steps to contain this virus.

Predicting the combined effects of case isolation, safe funeral practices, and contact tracing during Ebola virus disease outbreaks

BACKGROUND

The recent outbreaks of Ebola virus disease (EVD) in Uganda and the Marburg virus disease (MVD) in Ghana reflect a persisting threat of Filoviridae to the global health community. Characteristic of Filoviridae are not just their high case fatality rates, but also that corpses are highly contagious and prone to cause infections in the absence of appropriate precautions. Vaccines against the most virulent Ebolavirus species, the Zaire ebolavirus (ZEBOV) are approved. However, there exists no approved vaccine or treatment against the Sudan ebolavirus (SUDV) which causes the current outbreak of EVD. Hence, the control of the outbreak relies on case isolation, safe funeral practices, and contact tracing. So far, the effectiveness of these control measures was studied only separately by epidemiological models, while the impact of their interaction is unclear.

METHODS AND FINDINGS

To sustain decision making in public health-emergency management, we introduce a predictive model to study the interaction of case isolation, safe funeral practices, and contact tracing. The model is a complex extension of an SEIR-type model, and serves as an epidemic preparedness tool. The model considers different phases of the EVD infections, the possibility of infections being treated in isolation (if appropriately diagnosed), in hospital (if not properly diagnosed), or at home (if the infected do not present to hospital for whatever reason). It is assumed that the corpses of those who died in isolation are buried with proper safety measures, while those who die outside isolation might be buried unsafely, such that transmission can occur during the funeral. Furthermore, the contacts of individuals in isolation will be traced. Based on parameter estimates from the scientific literature, the model suggests that proper diagnosis and hence isolation of cases has the highest impact in reducing the size of the outbreak. However, the combination of case isolation and safe funeral practices alone are insufficient to fully contain the epidemic under plausible parameters. This changes if these measures are combined with contact tracing. In addition, shortening the time to successfully trace back contacts contribute substantially to contain the outbreak.

CONCLUSIONS

In the absence of an approved vaccine and treatment, EVD management by proper and fast diagnostics in combination with epidemic awareness are fundamental. Awareness will particularly facilitate contact tracing and safe funeral practices. Moreover, proper and fast diagnostics are a major determinant of case isolation. The model introduced here is not just applicable to EVD, but also to other viral hemorrhagic fevers such as the MVD or the Lassa fever.

Effect of Recombinant Vesicular Stomatitis Virus–Zaire Ebola Virus Vaccination on Ebola Virus Disease Illness and Death, Democratic Republic of the Congo

We conducted a retrospective cohort study to assess the effect vaccination with the live-attenuated recombinant vesicular stomatitis virus–Zaire Ebola virus vaccine had on deaths among patients who had laboratory-confirmed Ebola virus disease (EVD). We included EVD-positive patients coming to an Ebola Treatment Center in eastern Democratic Republic of the Congo during 2018–2020. Overall, 25% of patients vaccinated before symptom onset died compared with 63% of unvaccinated patients. Vaccinated patients reported fewer EVD-associated symptoms, had reduced time to clearance of viral load, and had reduced length of stay at the Ebola Treatment Center. After controlling for confounders, vaccination was strongly associated with decreased deaths. Reduction in deaths was not affected by timing of vaccination before or after EVD exposure. These findings support use of preexposure and postexposure recombinant vesicular stomatitis virus–Zaire Ebola virus vaccine as an intervention associated with improved death rates, illness, and recovery time among patients with EVD.

The Kivu Ebola Epidemic

The Kivu Ebola epidemic began on 1 August 2018, when four cases of Ebola virus disease (EVD) were confirmed in the eastern region of Kivu in the Democratic Republic of the Congo (DRC). The disease affected the DRC, Uganda, and is suspected to have also affected Tanzania, though the Ministry of Health there never shared information with the WHO. The outbreak was declared ended on 25 June 2020, with a total of 3,470 cases and 2,280 deaths. Other locations in the DRC affected included the Ituri Province, where the first case was confirmed on 13 August 2018. In November 2018, it became the biggest Ebola outbreak in the DRC's history, and by November, it had become the second-largest Ebola outbreak in recorded history, behind only the 2013–2016 Western Africa epidemic. On 3 May 2019, 9 months into the outbreak, the DRC death toll surpassed 1,000. In June 2019, the virus reached Uganda, having infected a 5-year-old Congolese boy who entered with his family, but this was contained. Since January 2015, the affected province and general area have been experiencing a military conflict, which hindered treatment and prevention efforts. The World Health Organization (WHO) has described the combination of military conflict and civilian distress as a potential "perfect storm" that could lead to a rapid worsening of the situation. In May 2019, the WHO reported that, since January of that year, there had been 42 attacks on health facilities and 85 health workers had been wounded or killed. In some areas, aid organizations have had to stop their work due to violence. Health workers also had to deal with misinformation spread by opposing politicians. Due to the deteriorating security situation in North Kivu and surrounding areas, the WHO raised the risk assessment at the national and regional level from "high" to "very high" in September 2018. In October, the United Nations Security Council stressed that all armed hostility in the DRC should come to a stop to address the ongoing outbreak better. A confirmed case in Goma triggered the decision by the WHO to convene an emergency committee for the fourth time, and on 17 July 2019, the WHO announced a Public Health Emergency of International Concern (PHEIC), the highest level of alarm the WHO can sound. On 15 September 2019, some slowdown of cases was noted in the DRC. However, contact tracing continued to be less than 100%; at the time, it was at 89%. In mid-October the transmission of the virus had significantly reduced; by then it was confined to the Mandima region near where the outbreak began, and was only affecting 27 health zones in the DRC (down from a peak of 207). New cases decreased to zero by 17 February 2020, but after 52 days without a case, surveillance and response teams confirmed three new cases in mid-April. As a new and separate outbreak, was reported on 1 June 2020 in Équateur Province in north-western DRC, described as the eleventh Ebola outbreak since records began; after almost two years the tenth outbreak was declared ended on 25 June 2020, with a total of 3,470 cases and 2,280 deaths.

Responding to the 2018-2020 Ebola Virus Outbreak in the Democratic Republic of the Congo: Rethinking Humanitarian Approaches

The Democratic Republic of Congo (DRC) presents a challenging context in which to respond to public health crises. Its 2018-2020 Ebola outbreak was the second largest in history. Lessons were known from the previous West African outbreak. Chief among these was the recognition that local action and involvement are key to establishing effective epidemic-response. It remains unclear whether and how this was achieved in DRC's Ebola response. Additionally, there is a lack of scholarship on how to build resilience (the ability to adapt or transform under pressure) in crisis-response. In this article, we critically review literature to examine evidence on whether and how communities were involved, trust built, and resilience strengthened through adaptation or transformation of DRC's 2018-2020 Ebola response measures. Overall, we found limited evidence that the response adapted to engage and involve local actors and institutions or respond to locally expressed concerns. When adaptations occurred, they were shaped by national and international actors rather than enabling local actors to develop locally trusted initiatives. Communities were "engaged" to understand their perceptions but were not involved in decision-making or shaping responses. Few studies documented how trust was built or analyzed power dynamics between different groups in DRC. Yet, both these elements appear to be critical in building effective, resilient responses. These failures occurred because there was no willingness by the national government or international agencies to concede decision-making power to local people. Emergency humanitarian response is entrenched in highly medicalized, military style command and control approaches which have no space for decentralizing decision-making to "non-experts". To transform humanitarian responses, international responders can no longer be regarded as "experts" who own the knowledge and control the response. To successfully tackle future humanitarian crises requires a transformation of international humanitarian and emergency response systems such that they are led, or shaped, through inclusive, equitable collaboration with local actors.

Preparedness Through Urban Resilience

This book explores the topic of resilience at the city level. The focus is more on outbreak events at the city level, or how cities should prepare and react in facing the larger events of epidemic and pandemic.