Everybody knows that pestilences have a way of recurring in the world; yet somehow we find it hard to believe in ones that crash down on our heads from a blue sky. There have been as many plagues as wars in history; yet always plagues and wars take people equally by surprise.
—Albert Camus, The Plague
The most recent Ebola epidemic that began in late 2013 alerted the entire world to the gaps in infectious disease emergency preparedness and response. The regional outbreak that progressed to a significant public health emergency of international concern (PHEIC)2 in a matter of months killed 11,310 and infected more than 28,616 (WHO, 2016a). While this outbreak bears some unique distinctions to past outbreaks, many characteristics remain the same and contributed to tragic loss of human life and unnecessary expenditure of capital: insufficient knowledge of the disease, its reservoirs, and its transmission; delayed prevention efforts and treatment; poor control of the disease in hospital settings; and inadequate community and international responses (WHO, 2015d).
The Ebola virus outbreak began in late 2013 with the fatal infection of a young boy in Guinea who might have contracted the virus from a species of bat, the disease’s putative natural reservoir (WHO, 2015d).3 Retrospective studies
1 The planning committee’s role was limited to planning the workshop, and the Proceedings of a Workshop was prepared by the rapporteurs as a factual account of what occurred at the workshop. Statements, recommendations, and opinions expressed are those of individual presenters and participants and have not been endorsed or verified by the National Academies of Sciences, Engineering, and Medicine, nor should they be construed as reflecting any group consensus.
2 PHEIC is defined in the International Health Regulations (2005) as “an extraordinary event, which is determined, as provided in these regulations: (a) to constitute a public health risk to other states through the international spread of disease; and (b) to potentially require a coordinated international response. This definition implies a situation that is serious, unusual, or unexpected; carries implications for public health beyond the affected state’s national border; and may require immediate international action” (WHO, 2016b).
3 Bausch and many others now favor the term “Ebola virus disease” instead of “Ebola hemorrhagic fever” to describe the disease caused by the Ebola virus, which in this document is denoted simply as “Ebola.”
identified the index case of Ebola in West Africa as an 18-month-old boy who died in late December 2013 in Meliandou—a remote, tiny village in the forested region of Guinea (WHO, 2015d). By mid-January 2014, several members of the boy’s family had died of the disease, along with several traditional healers, as well as health care workers at a nearby hospital in the city of Guéckédou. After that, members of the boy’s extended family who had attended funerals, or who took care of ill relatives, also succumbed. Following an alert issued on January 24, a small team of local health officials investigated several deaths in Meliandou, noting cholera-like symptoms.4 A larger team from Médecins Sans Frontières (MSF) concurred with these observations a few days later.
On February 1, 2014, an infected member of the boy’s family traveled to the capital city, Conakry; 4 days later, he died in a hospital there. Over the course of the month, cases were reported across a widening geographic area. The Guinean Ministry of Health issued its first alert regarding the mysterious, deadly disease on March 13, the same day the World Health Organization’s (WHO’s) regional office mobilized in response to the disease, which they suspected to be Lassa fever.5 At the same time, MSF, suspecting Ebola, sent teams to Guéckédou that began arriving on March 18 to investigate the outbreak and care for the sick (MSF, 2015).
Epidemiological investigation quickly established links among known outbreaks and identified Guéckédou as the epicenter of transmission for the yet-unidentified disease (MSF, 2015; WHO, 2015d). On March 22, Ebola-Zaire was determined to be the causative agent through diagnostic testing performed on a sample sent to a biosafety level-4 (BSL-4) laboratory in Lyon, France (Baize et al., 2014). The WHO publicly announced the outbreak the following day, by which time 49 cases and 29 deaths had been officially reported. Meanwhile, the virus had spread to Liberia and Sierra Leone, but as in Guinea, early cases in these countries were not detected, investigated, or formally reported. On March 31, MSF publicly declared the outbreak “unprecedented” owing to its geographic spread: a conclusion that the WHO initially questioned, and which was widely dismissed as alarmist (MSF, 2015), but which ultimately was borne out after chains of transmission multiplied, entered the capital cities of Sierra Leone and Liberia, and became so numerous they could no longer be traced (WHO, 2015d).
As the ill started to carry the disease into hospital settings, health care workers became infected, which dramatically increased the disease’s distribution: between April and August 2014, the number of cases jumped from 49 in Guinea to 3,685 across all of West Africa (Meltzer et al., 2014). By July, the virus had
4 Cholera, the cause of a major outbreak in West Africa in 2012, is difficult to distinguish from Ebola in its early stages. The same is true for malaria and for Lassa fever, a viral hemorrhagic fever of high incidence in West Africa (WHO, 2015d).
5 Lassa fever is an acute zoonotic viral illness endemic in parts of West Africa, including Guinea, Liberia, Nigeria, and Sierra Leone. More than 100,000 people in West Africa become infected with the Lassa virus each year and approximately 5,000 die. SOURCE: http://www.cdc.gov/vhf/lassa (accessed November 3, 2016).
been imported to Nigeria. However, because of a rapid response that featured thorough contact tracing and effective isolation of patients, chains of transmission were quickly extinguished in that country (see subsequent section, “Nigeria Stops Ebola”). Additional cases were subsequently imported without significant further transmission to Mali, Senegal, Spain, the United Kingdom, or the United States (MSF, 2015; WHO, 2015a).6 But once Ebola had managed to cross the ocean, and the disease “became an international security threat, and no longer a humanitarian crisis affecting a handful of poor countries in West Africa,” remarked MSF international president Joanne Liu, then “finally the world began to wake up” (MSF, 2015). By February 2015, the WHO estimated that the number of cases had reached 23,253 (Srivastava, 2015).
Despite the good intentions of governmental and humanitarian aid groups, weak health systems in West Africa, financial strains, and bureaucratic policies prevented the successful implementation of adequate prevention efforts in the susceptible areas (Bausch, 2015; WHO, 2015d). This translated to sluggish responses to the outbreak in these regions. Importantly, although the first case likely occurred in December 2013, MSF, the WHO’s Regional Office for Africa (AFRO), and other aid groups in the area did not confirm the identity of the pathogen until 3 months later, in March 2014 (WHO, 2015d). By that point, the disease had taken root in West Africa and had outpaced the health care and epidemiological arsenal available (WHO, 2015d).
Recognizing the opportunity to learn from the countless lessons of this epidemic, the Forum of Microbial Threats convened a workshop in Washington, DC, in March 2015 to discuss the challenges to successful outbreak responses at the scientific, clinical, and global health levels. By the time of the workshop, almost 25,000 cases had been reported and more than 10,000 lives claimed by Ebola. Over the course of 2 days of presentations and discussions, workshop participants explored the epidemic from multiple perspectives, identified important questions about Ebola that remained unanswered, and sought to apply this understanding to the broad challenges posed by Ebola and other emerging pathogens, to prevent the international community from being taken by surprise once again in the face of these threats.
Building on previous outbreak workshops, the forum convened March 24 and 25, 2015, at the Pan American Health Organization headquarters in Washington, DC, to understand the recent developments in incidence, prevalence, and
6 Cases were also later reportedly imported to France, Germany, Italy, the Netherlands, and Switzerland.
intervention strategies used to mitigate the disease in an increasingly interconnected world. James Hughes of Emory University mentioned, “We have to continue to expect the unexpected, and we have to continue to work towards ensuring sustainable engagement of all the partners, domestically and internationally, that are needed to really address these root causes.” This Proceedings of a Workshop summarizes the presentations and discussions that took place over the 2-day meeting. For meeting objectives, see Box 1-1.7
This Proceedings of a Workshop summarizes the presentations and discussions of the Washington, DC, meeting, and consists of the information presented, questions raised, and improvements recommended by individual workshop participants. Chapter 2 outlines the trajectory and response to the most recent Ebola outbreak that occurred in West Africa. It includes lessons learned from previous outbreaks that could have been applied to this one, the distinction between this and previous outbreaks, and the challenges in Ebola treatment and control. Chapter 3 discusses case examples of emergency response and preparedness around the world. Finally, Chapter 4 delves into the current and future research opportunities to study the transmission, diagnosis, proper containment of the ill, and vaccine development. It also discusses the importance of developing a global health risk framework in case of another Ebola-like disease outbreak.