What caused the West African Ebola outbreak?
Controlling Ebola virus requires vaccines and antiviral therapeutics.
The Ebola virus was first recognized as a human pathogen in 1976, when outbreaks of hemorrhagic fever occurred in areas of Sudan and Zaire between August and November of that year. These outbreaks were attributed to Ebola virus, a new filovirus agent. More than 40 years later, we know that Ebola virus persists in nonhuman animal reservoirs in the wilds of Africa and likely elsewhere, and that inadvertent human contact with these reservoir species can facilitate zoonosis, which is the transmission of an infectious agent, in this case Ebola virus, from nonhuman animals to humans. Once present in a human population, Ebola virus is highly transmissible through person-to-person contact and can rapidly spread through a population having no preexisting immunity to the virus. Because Ebola virus can trigger a massive inflammatory response, and its viral proteins mediate immune evasion processes, the infection can result in great lethality.
Among the filovirus family, outbreaks of Ebola virus are particularly lethal. The 2014 West Africa Ebola pandemic case/fatality rate was greater than 67% in Guinea alone. The initiation and spread of the pandemic was a direct result of 1) zoonotic transmission to humans, 2) direct human-to-human spread, and 3) lack of antiviral treatment or available vaccine to protect the at-risk population from Ebola virus and associated disease. Although failed measures to regulate human encroachment on wilderness areas amidst a growing population concomitant with lack of an effective public health infrastructure certainly underlie the 2014 outbreak, a sheer lack of approved vaccines or antiviral therapeutics to combat Ebola virus infection can be held responsible for the inability to halt the spread of Ebola virus across West Africa, thus only facilitating the pandemic. Development of effective vaccines and antivirals against Ebola virus, and their application to at-risk and infected populations and individuals, is paramount for the prevention of future outbreaks and controlling pandemic spread of this deadly virus.
Michael Gale Jr., PhD, is a professor of immunology at the University of Washington School of Medicine and director of the UW Center for Innate Immunity and Immune Disease. Disclosure: Gale reports that Ebola virus research in the Gale lab is supported by the NIH.
Weakened health systems fueled the Ebola outbreak.
As the death toll from the recent Ebola outbreak rose, the usual answers to how it got so huge so quickly — poverty, bad governance, cultural practices, endemic disease in Guinea, Liberia and Sierra Leone — gave way to a deeper questioning of the structural causes of the poor public health response. International lending policies, including and especially those employed by the International Monetary Fund (IMF), should carry much of the blame.
The IMF has been active in the region since the early 1960s and continues to exert an enormous amount of influence on how governments can dictate their own health policies. Through mechanisms known as conditionalities, the IMF requires cuts (such as wage caps on health workers, as well as critical infrastructure development) to the same public systems that could have responded to the Ebola crisis before it swept across the country. When countries sacrifice budget allocations to meet macroeconomic policy prescriptions, as per the IMF’s decree, it leaves countries without money to fund basic infrastructure. Health facilities are left crumbling, sometimes without access to water or electricity, and completely unprepared for complex emergencies. Few health workers are trained in infectious disease control, and those who receive training lack protective equipment and materials due to nonfunctioning supply systems.
There is a growing chorus calling for reform to IMF policies, and the slow response to Ebola shone a light on just how weakened the health systems have become after decades of restrictions in the name of economic reform. Serious IMF reform, including the abolition of conditionalities and the cancellation of debt, are needed to better equip countries to respond to the next pandemic.
Julia Robinson, MPH, is a clinical instructor of global health at the University of Washington School of Public Health. Disclosure: Robinson leads Côte d’Ivoire and advocacy programs at Health Alliance International.