Media sources, politicians, and others have treated the current Ebola outbreak in several countries in West Africa as a complete surprise, and therefore, as an unpredictable threat. This “surprise” was not surprising at all. “Unprecedented is a moniker that I seldom saw prior to 9/11. Since then, it has become a cliche. The Ebola epidemic has been described as “unprecedented.” However, it was not unprecedented.
Had it not been Ebola, it would have been Lassa Fever, Marburg, or other hemorrhagic fevers. It could have been many diseases. In fact, the conditions have been ripe for this sort of outbreak for decades–and something like this happened before: SARS. “Emerging infectious diseases” or EIDs have been so notable in infectious diseases and epidemiology that a monthly journal of that title is already in volume 20. It has become one of the most influential journals in the field, with an impact factor of over 7, and has the third highest impact of all infectious disease journals (ISI). The first Institute of Medicine (IOM) report on emerging infectious diseases was published in 1992, and had a tremendous effect on the scientific community, on public health agencies ranging from the local to the WHO, and on policymakers and legislators throughout the world. Laurie Garrett’s well known book, “The Coming Plague,” was published in 1994–twenty years ago. For at least the past 25 years, EIDs have been prominent in my own thinking. The spread of a virus such as Ebola virus was inevitable.
Why the inevitability? Because of social, economic, and demographic changes in societies around the world. Because of economic globalization, and intensifying transportation ties worldwide. The 1992 IOM report identified the “factors in emergence,” and 5 out of the 6 that were identified were social. The sixth, “microbial adaptation and change,” is also social. What the IOM was referring to was the proliferation of antimicrobial resistance, which I will write about in a subsequent blog. The decision to use antimicrobials has a strong social dimension–public expectations of receiving a prescription, lack of public knowledge that these molecules are useless against bacteria, and the spread of antimicrobials to small pharmacies in developing countries, and, indeed, to street markets, where they may be bought freely. And, of course, the use of antibiotics to promote growth in livestock and poultry accounts for 70% of antibiotic use by volume.
Against this backdrop, where viruses and other microbes have existed in micro-foci in isolated portions of rainforest in many tropical areas, and where increasing connectivity with urban areas has constituted a demographic revolution, pathogenic viral and bacterial agents have had a rapidly increasing chance of spreading. It was entirely predictable, and many of us wrote and spoke of this near certainty. Any uncertainty concerned which agent, and where, and when. Predictive epidemiology is not yet at the point where the when and the where could be pinned down.
So was the spread of Ebola a real surprise? Not to those of us in the field. Indeed, not to those of us who saw the movie “Contagion” and realized the scientific basis for that excellent film, which I use as a teaching tool. And not to those of us who realize that the regular and periodic emergence of new influenza strains also represent disease emergence.
The current epidemic was not a surprise. In most ways, it is not even “unprecedented”–a word that I hope to never use in my writing! Not an unpredictable threat: just a threat to health, and, indeed, to economies. Once this outbreak diminishes, and it will, there will be other Ebolas in the future. Because of this, we will need novel public health interventions, and we will need to apply an old intervention on occasion: quarantine, or, the more palatably named “social distancing.” It points to the importance of the public health disciplines to society, and the importance of funding basic and applied epidemiology. I will write more about this issue of funding in the coming weeks.