The world is currently facing the second largest epidemic of Ebola virus in recorded history. Let me say that again, the 2018-19 Kivu epidemic is now the 2nd largest outbreak of the virus behind only the 2014 West African Ebola epidemic in both total cases and deaths. Ebola virus seems to be on the way to becoming an endemic disease in Africa which could pose a serious threat to humanity. The more a virus like Ebola circulates in the human population, the more likely it will mutate and become more dangerous; not just to the areas of Africa traditionally plagued by Ebola, but potentially to the rest of the world as well.
Ebola is one of those rare sicknesses that is so terrible, so gruesome, and so deadly that it rightly inspires terror in the average person when they hear the word, and it has become nearly a household name. Although historically a very minor virus in terms of total numbers of affected and killed (more people die in the US from Influenza every year than have ever died from Ebola in the recorded history of the virus) it is still one of the most feared viruses on the planet and it has inspired books, movies, and TV series as a result. Only a handful of well-known viruses and diseases have made it to the elite level of global sensation, diseases like HIV/AIDS, Zika, smallpox, plague/The Black Death, and Ebola.
And if you think you can maybe dispel this fear by learning more about the Ebola virus, you know, the whole “you fear the unknown” thing? Let me dissuade you of that right now. After four years of exhaustive research for my current book project, Emergence, I can tell you that the more you learn about this virus the more terrifying it becomes.
Ebola is classified as a filovirus, and one of only a few that science has so far discovered. Among the members of this viral family tree are several subtypes of Ebola, including Reston virus, the only Ebola that does not cause disease in humans. Then there is Marburg virus and the relatively newly identified Cuevavirus that may only infect bats. Bats, specifically fruit-eating varieties, are believed to be the natural reservoir species that carries filoviridae of every variety. They are the only known animal in nature to show antibody response to Ebola virus, indicating the virus cycles in their system but their immune response is sufficient to survive it.
Until recently Ebola epidemics typically occurred in isolated villages in Africa. That trend is beginning to change, though, and the increased mobility of rural populations has brought Ebola to new areas, including modern cities. In 2014 more than 28,000 people died when Ebola virus infected the population of several large villages and towns as well as dense urban city populations in West Africa. For the first time the world saw how dangerous and devastating a filovirus could be when given the opportunity to amplify and spread in the dense populations of modern cities.
One of the reasons Ebola can be difficult to stop in certain settings is the fact that it has a long incubation period, sometimes as much as 21 days, before the virus begins to affect the patient. While patients won’t be infectious until symptoms appear, that length of time could allow them to move out of any isolation or quarantine zones before showing the first signs of the virus. And it makes tracking where and when exposures occurred incredibly difficult.
When an infection begins the virus typically sneaks in and the person isn’t even aware of the exposure. The virus is so virulent that if as few as 5-10 particles of the virus get into a person’s body it’s typically sufficient to spark a full-blown infection. The first signs might be mild headache, low fever, body aches and other generic symptoms similar to malaria, influenza, and about two dozen other viral infections. The symptoms don’t stay mild, though. Fever increases to alarming levels, diarrhea, and vomiting are typically bloody and violent. For some patients this period is severe enough that they die from dehydration.
The hemorrhagic fever aspect of the virus is what sparks fear in the mind and heart, though, and some patients are worse than others. They may bleed from needle sites, eyes, ears, nose, mouth, and even sweat glands as the blood’s ability to clot is reduced. Ironically, at the same time they are bleeding in some places, many patients will have severe clotting in others with massive blood clots developing in the spleen, liver, and kidneys. As these symptoms worsen, the blood vessels in their bodies begin to break down and large bruised patches develop beneath the skin. The final stage of the disease caused by Ebola virus is often bloody and painful. Blood loss itself kills some, but a small percentage. For most it is dehydration, pulmonary edema, kidney or liver failure, heart attack, or some other resulting effect or symptom of the disease that causes death in the patient.
For some strains of Ebola virus as many as 80% of the people infected will die compared to a measly 0.15-0.2% average mortality of common influenza virus. The truth of Ebola is so terrifying that it has sparked a cultural phenomenon resulting in such popular works as Outbreak by Robin Cook or The Hot Zone, by Richard Preston. In other words, given the reality of what Ebola actually is, the fear is fully justified. After years of study and research, Ebola scares the hell out of me.
And, given how it appears to easily amplify in urban settings, it should scare the hell out of everyone.
But terrifying as it is, Ebola is not a worst case scenario, not yet, not as it is. During my research, I realized that the Ebola virus is limited by the fact that it requires direct exposure to the bodily fluids of an infected patient. As a result person to person transmission is typically slow and limited, making the chain of transmission easy to break. However, with its virulence, long incubation period, and lethality, if the Ebola virus were suddenly as easy to spread from person to person as influenza it would be impossible to stop and could threaten humanity itself.
It was that realization that led me to start researching diseases, and how they’ve impacted humanity in the past. The nearest thing I could find to a potential species threatening pathogen that had actually hit the human population was the Black Death of the mid-14th century that swept through Europe and killed nearly half of the population of Europe and western Asia. While that pathogen could never have wiped out all of humanity in any real scenario at the time since population densities were so low, but it very nearly wiped out the population of Europe. Whole towns and villages were wiped off the map during those years of darkness, fear, and pestilence. And in the wake of the Black Death European society was forever changed.
I wondered how that kind of situation would play out today? What would happen if a virus suddenly arose and swept through the world, killing half of the people alive on the planet, maybe more? Would modern society be able to survive that kind of catastrophe, or would there be a collapse similar to that in Europe at the end of the Black Death? It was those questions, and more like them, that led me to viruses and Ebola, specifically. I wanted to learn as much as I possibly could to make my fictional virus seem not only plausible, but possible.
I realized early on in that research that the most perfect virus I could construct, the one that would truly be a terrifying global killer, was a virus with all of the natural properties of Ebola, but with a transmission rate so high that anyone who comes into close proximity with an infected patient is at risk. If a virus like that were unleashed today, our urban lifestyle and culture would make us exponentially more vulnerable to it. As we’ve already seen, denser populations can drastically increase the spread of Ebola, even with how difficult it is to spread from person to person with casual contact. The simple barrier procedures that work so well in arresting the transmission and spread of Ebola would be completely useless against such a virus.
Science has already proven that once filoviruses get into dense populations they tend to begin spreading rapidly. Part of this spread is due to what are known as super-transmitters. These individuals transmit the virus to many times the normal average number of people, creating rings of infection that grow extremely quickly. This type of spread makes the virus very difficult to track and interrupt in dense populations such as urban environments as it allows the virus to jump from one person to a large number of dispersed people rapidly, and has an incubation period that could last up to two weeks before symptoms appear.
This type of super-transmission was recorded during the original Marburg epidemic in Germany. From that incident, epidemiologists learned that super transmitters are typically people with jobs that put them in contact with large numbers of people on a daily basis such as servers at restaurants, bartenders, grocery store clerks, teachers, and healthcare professionals. The primary contacts would be individuals that come into direct contact with the super transmitter and acquire the virus, secondary contacts are the ones that come into contact with infected primary contacts. As the rings of infected get broader, they encompass more and more people. In the end, one infected person with a high volume job that continues to work after becoming symptomatic could infect hundreds, possibly thousands of people through those multiple layers of transmission. This is a unique characteristic of urban populations and can amplify a virus rapidly. In the Marburg epidemic one hotel clerk was believed to have resulted in more than two hundred direct exposures to the virus.
Thankfully Marburg and Ebola do not appear to be easily transmitted or airborne, but we have already found some evidence that certain other types of filovirus may be. Cuevavirus, a filovirus which infects bats, is possibly airborne and seems to have an ability to spread through bat colonies rapidly as a result. In some bat colonies in Europe it appears individual strains of the virus may have swept through populations of thousands of bats in a remarkably short time, such as days or weeks. For humans that would be the equivalent of a virus affecting most of the population of a modern mega-city like Tokyo in less than a month.
In Emergence, I combined all of the worst parts of the Ebola virus with all of the worst possible improvements that could be imagined. This fictional virus, named the Jurua virus for the river on which it emerges, a tributary of the Amazon, enters the human species and infects the city of Manaus with a dense population of more than 2 million people. It hits in an area no one is expecting a filovirus to show up, the heart of the western Amazon, near the border with Brazil and Peru. Manaus is the largest city in that part of the world, a modern metropolis with a dense population and thriving industry. It’s also a city with a busy international airport.
When the Jurua virus goes from airborne to air traveler, humanity hangs in the balance.
With the world facing the second largest epidemic of Ebola virus in history less than five years after the largest, it’s a scenario that could go from nightmare to reality faster than we think.
Emergence, book one of the Red Death, is coming soon..