Ebola’s Deadly Path
By John McCormick
EBOLA. HOW DANGEROUS IS IT TO YOUR family? To Africa? The short answer to the first question is simple and comforting. If you live in a developed country, there is virtually no chance you or anyone you know will even run into someone who has or will catch Ebola.
The answer for much of Africa and large portions of the world in general is very different and will have a drastic effect in these countries.
Ebola is correctly seen by many as an existential threat to the people and economies of the world for the simple reason that, while only 10,000 people were infected by mid-October, by January there will be millions of infected and about eighty percent of those will die even with the best of care possible in the regions where the outbreak occurs.
That number is based on current conditions and plans already in place to increase aid. In other words, that is the best case scenario.
If nothing were done to interfere with the progress of Ebola (efforts such as finding a vaccine or running out of potential new victims as the population dies) there would be one billion victims by the end of next year. They would require four billion health care workers.
So, despite political demagoguery in this country and calls for isolationism, the only real way to keep safe is for developed countries to open not a valve but a floodgate of assistance to any location with an Ebola outbreak.
Infectious diseases with no available vaccine (such as Ebola) will spread in a population depending on two main factors.
• How many people there are available to infect—e.g., city slums versus rural villages. If the population is small it won’t spread far or fast simply because there are fewer people to get infected. In previous outbreaks, we were lucky because they occurred in isolated rural areas. The current outbreak is in a city slum.
• How many other people are likely to be infected by each new victim. If it is highly infectious, then many new patients will catch it for every original victim. That isn’t so obvious, but is well understood.
This second factor is known in epidemiology as the R0 factor (in nuclear physics a similar factor is the K0 factor). Sometimes called basic reproductive ratio, it can be described as the number of cases one case generates on average over the course of its infectious period, in an otherwise uninfected population. With some diseases this number is large. For example, for each case of measles the R0 factor is 18, meaning each new patient will probably infect 18 more.
Other common diseases have the following R0 factors reflecting just how contagious they are:
Pertussis (whooping cough) 17
Mumps and smallpox 7
HIV/AIDS 5
Ebola estimated to be about 2.2
Research continues and the numbers for Ebola are between one and 2.2 in different regions, but it is well established that the maximum is less than 2.5.
That may seem very reassuring, especially compared to the other diseases listed. On average only two people will be infected by each new patient—remarkably enough, that is exactly what happened in Dallas where two healthcare workers became infected caring for the only person who came into the U.S. from Africa and later developed Ebola symptoms.
(Note: that latter is important because, unlike many diseases, a person isn’t infectious unless he or she is already showing serious and obvious symptoms.)
None of Thomas Eric Duncan’s forty-two casual contacts, even people who stayed in the same apartment, became infected although he was quite ill at home and later died in hospital despite getting the best possible care.
While an R0 factor of two seems very low, unfortunately (something those of you with a knowledge of physics have already noticed) in this context two is a dangerous number. In the fission of U-235, approximately two neutrons are released and will split two more uranium atoms in a critical mass. In other words, a growth factor of two mathematically results in an exponential growth and is sufficient to sustain a nuclear explosion.
(In a reactor, the factor is held to about one with moderating materials that absorb, on average, one of the two neutrons, or because the uranium is so spread out that one neutron will decay before striking and fissioning another atom.)
A growth factor of two is enough to kill millions in nuclear physics or in an epidemic. Not such a comforting number after all, is it?
In fact, because there is no current immunization available for Ebola and none likely to be available for many months (at a minimum), Ebola cases will continue to expand at an exponential rate until either seventy percent of new patients are isolated before infecting any others, or it runs out of people to infect.
Exponential growth means each successive week, until the epidemic is brought under control, the number of new cases will be approximately equal not to double the number of patients the last week, but by the total of all previous week’s new cases added together.
Many events/processes in biology and nature follow a similar growth pattern. A Fibonacci sequence (often seen in nature) is similar but only adds the previous two numbers together, yet it grows very quickly :
1, 1, 2, 3, 5, 8, 13, 21, ... [F(n) = F(n-1) + F(n-2)]
Compared with Ebola numbers, this number grows more slowly.
Every expert in the field agrees that the published numbers for Ebola victims must be seen as very much on the low side because rural cases won’t be recognized and reported due to the lack of medical care and also because of families’ fear of being shunned by neighbors.
Official infection and death numbers are based on laboratory confirmed cases and, until recently, it took about four days to obtain laboratory results. Now, at least one foreign laboratory has been set up in West Africa and can produce reliable test results in a few hours.
Official estimates are that the real number of Ebola patients and fatalities (as opposed to the formally diagnosed cases) is probably double the number being reported in press releases and news reports. Keep that in mind when you hear reports of the number of cases and number of deaths. Remember that this is a Third World region with few good roads, no health care infrastructure, and poor communications and record-keeping.
Multiply the TV news numbers by two and even that may be low.
Epidemiologic studies indicate that, to contain Ebola and see the current epidemic die out as did earlier outbreaks, at least seventy percent of patients must be isolated and in treatment before they spread the disease to anyone else.
That was extremely difficult when there were 1,000 new cases each week in a
Third World country.
How difficult will it be when 100,000 new cases occur the first week in February? How about 400,000 by the end of February?
Far-fetched? Unfortunately not.
By the first of November there were about 10,000 diagnosed cases. The World Health Organization (WHO) estimate of new cases for the first week of December is between 5,000 and 10,000 that week. By the second week in December that would rise to between 10,000 and 20,000 new cases in one week.
The Centers for Disease Control (CDC) in Atlanta, has developed a model for the spread of Ebola if the world does not take much more vigorous actions to intervene than are now planned. That CDC projection shows it is possible there could be 1,400,000 cases in West Africa by February, 2015.
That is based on a number of suppositions, including that the outbreak will remain confined to West Africa, not a sure thing at all, and that the promised help will arrive on schedule.
Ebola vs. Flu
People fear Ebola in part because it is a virus and the only virus infections most people are familiar with are the common cold and the yearly flu, both of which spread rapidly and infect perhaps a hundred million each year, killing tens of thousands, perhaps 100,000 worldwide, fewer than about one percent.
The big difference between those infections and Ebola is that the flu, for instance, doesn’t usually kill the patient and therefore infected people are mobile while ill and spread the infection to many more people.
Ebola kills so quickly and is so debilitating early on that few people are ever exposed to the patients when they are actively vomiting or have diarrhea.
Neither influenza or the common cold are “technically” airborne. They actually spread the same way Ebola does, by contact with bodily fluids through an open wound or the eye. If they were more deadly, people would wear N-95 masks and wear gloves in stores during the flu season.
Colds and flu are not a necessary part of winter. You can keep from catching either by staying several feet away from any infected person, never touching your face after being in stores, on public transportation, or the office. Touching a surface with droplets of infected bodily fluid and then touching your face is the most common way of transmitting viral infections.
(Having been a caregiver for some elderly relatives and being somewhat immune compromised myself, during flu season I shop at off-hours when there are fewer people in stores, have many items delivered, and wear gloves while shopping. I also use alcohol hand wipe every time I leave a store. I haven't had either the flu or a cold in two decades.)
Can Ebola Become Airborne?
In medical terms there is a specific definition of the term “airborne” which is not really clear, leading the WHO and the CDC to disagree, but which essentially implies two things.
First, the virus can survive being dried out and just a few are enough to
cause the person to get sick. Second, the virus has a protein component which can attach to a cell in the
nose or throat.
The Ebola virus, unlike human or animal cells, depends on RNA, not DNA for replication. RNA is less dependable and therefore is more likely to develop errors. However, although this virus probably mutates a bit every time it multiplies and certainly every time it passes from one host to another, it hasn’t changed to the point where it is airborne.
[The Ebola virus, right, showing internal structures. The Ebola virion is 80nm in diameter and up to 1400nm long. Model is based on x-ray analysis and is courtesy of Visual Science Company.]
You might think that is a major worry, because if Ebola became airborne it would spread around the world rapidly, whereas now it can only be passed through direct fluid contact with an infected and ill patient.
When thinking about this possibility, it is important to recall that although Ebola was only medically identified in the 1970s, it is certain that it has been around in one form or another for thousands if not millions of years in animals, and in humans. In all that time it has certainly mutated millions or billions of times yet has never become airborne.
Because so little is known about how viruses really operate or what mutations are possible, people are afraid of any dangerous virus becoming airborne. All we really have to go on is one-hundred-plus years experience with various viral infections. In all that time, no human virus has ever been seen to mutate into airborne form.
HIV-1 and Hepatitis C have infected millions and mutated billions of times yet neither one has ever been transmitted in airborne fashion.
Stopping Ebola
Ebola is a negative-strand RNA virus belonging to the family Filoviridae. There are more than one kind of Ebola, some very deadly including the Zaire subtype which is behind the current epidemic.
Because there is no vaccine and no real treatment, to stop this epidemic all patients must be isolated in special hospitals or care centers. Existing facilities were filled months ago. The countries involved have all recently suffered revolutions and/or a disastrous economic setback and were barely starting to rebuild their health care infrastructures when the outbreak began.
At the start of the outbreak there were about 320 doctors total in the three countries affected—Liberia, Guinea, and Sierra Leone. Many of them and the other health care workers have since died of Ebola simply because they lacked isolation supplies and training.
(Médecins Sans Frontières/Doctors Without Borders or MSF, have been treating Ebola patients for decades with a great safety record for their workers.)
To isolate seventy percent of patients and thereby contain the epidemic, those infected must be located and their contacts traced, isolated, and followed for the twenty-one-day incubation period so those who are infected by them can themselves be isolated.
That means that at a minimum, new facilities must be built, staffed, supplied, and activated at a faster rate than new cases occur.
Unless the world surges thousands of medics and scores of construction crews into the region in the next few weeks, by early next year that would require nearly 1,000,000 new isolation beds and several million trained and equipped health care workers.
In other words, unless we stop Ebola now it will spread until it runs out of people to infect.
With an additional 100,000 to 200,000 new beds and 300,000 to 600,000 additional health care workers and associated supplies by mid-December, there is a chance we can contain it.
As difficult as it is politically to surge thousands of military and civilian contractors to the region to immediately build new facilities while the numbers are still somewhat manageable (in the tens of thousands in November), the experts say that is the only way to stop this epidemic.
President Barack Obama (over the fanatical objections of Republican politicians in the House and Senate) has promised to send a military expedition to build seventeen one-hundred-bed Ebola isolation units. Other countries are also contributing. China and even Cuba are sending supplies and medics. But even if the number of new beds doubles every week, the gap between the number of patients and number of beds will continue to grow because the patient load grows exponentially, so doubling the number of beds can’t catch up with the demand.
To get ahead of the epidemic, the U.S. contribution should be about ten times the current plan and the same for other countries’ contributions.
The U.S. contribution only includes a crew to build the facility. They will have no contact with patients and, because they are military, there will be no problem isolating them after they return.
But the U.S. action may be more window-dressing than real action. Despite this country having a large number of well-trained biological and chemical troops who could quickly and safely be used to care for Ebola victims, none of them are scheduled to be sent to Africa to assist.
Each patient requires three caregivers who can’t be permitted to treat non-Ebola patients. So 10,000 patients would require 30,000 health care workers. That is approximately ten times the total number of native workers in the involved countries. A week later 20,000 patients would require 60,000 caregivers well enough trained to both care for the patients and to keep safe from catching Ebola themselves.
Estimates published in the October 18, 2014, issue of “The Economist” state it costs about $170,000 to build a seventy-bed facility and costs about $1,000,000 to operate it for one month. Based on WHO estimates, it would cost about $2 billion each month to operate 100,000 Ebola beds. Ban Ki-moon, Secretary General of the U.N., says that he believes there needs to be a twentyfold increase in assistance over the currently pledged aid.
Historical background
Ebola was first detected in 1976 by scientists in Antwerp, Belgium, from samples taken from a dying nun in what was then Zaire. Rather than stigmatize the location and adopt the name of the actual village where this occurred, the Belgian scientists named the new virus for a nearby river, the Ebola.
That was thirty-six years ago and there have been a number of outbreaks since then, approximately twenty individual outbreaks with about 320 victims, nearly 300 of whom died.
Each of these earlier outbreaks ceased mostly on their own because they occurred in small isolated villages in central Africa—there simply wasn’t enough of a population to enable the disease to spread.
Unfortunately, the 2014 outbreak either originated in a crowded slum or was quickly spread there by some villager who caught it from an animal—either a monkey or fruit bat.
Congressional hearings in October pointed to the unintended consequences of the Republican-sponsored government gridlock in the U.S. While Republican representatives excoriated CDC and other administration public health officials for their lack of planning and preparedness for such a possible epidemic, retiring Rep. Henry Waxman (D-Calif.) shot back at his fellow members in the House Panel hearings that the same politicians who are complaining loudly that the Obama Administration, CDC, and NIH aren’t properly staffed and equipped to deal with the threat are part of the very Republican caucus responsible for the sequestration’s irrational across-the-board budget cuts.
In other words, the Republicans are playing politics with this major threat to the world’s health by attacking the very institutions they themselves made certain were underfunded and therefore completely unable to prepare for any such disaster.
World Consequences
In addition to the tragedy of watching while millions of Africans die horrible deaths, there is the very real possibility that Ebola could spread beyond a few small countries in West Africa. There have already been cases in the U.S. and Spain.
A blockade of those regions with cases is often suggested by demagogic politicians who ignore reality and play on the fears of the public for personal gain.
The simple fact is that, yes, people can leave Guinea, Sierra Leone, and Liberia by airplane, but they can also walk or ride to another country—by the third week of October an infected and very ill child had been taken by her grandmother to the country of Mali. The WHO confirmed that two people traveled from Guinea by public transportation to Kayes, a city (mostly slum) of more than 100,000 in western Mali on the Senegal River.
“The patient is a two-year-old girl, who recently arrived from Guinea accompanied by her grandmother. The child’s first contact with the country’s health services occurred on 20 October, when she was examined by a health care worker at Quartier Plateau in Kayes, a city in western Mali on the news," reported the WHO. Kayes has a population of around 128 000 people. It is located about 600 kilometers from the capital city of Bamako and lies near the border between Mali and Senegal.
The child has since died but provided proof that Ebola can easily spread beyond the three countries where it is epidemic.
In addition, there is no legal framework that permits the U.S. or any other country to stop all travel out of those three countries short of declaring war.
Because no direct flights go from the three West African countries to the U.S., direct travel is already impossible—people traveling to the western hemisphere from West Africa normally go through a European airport.
So, there is no practical way to isolate the countries where the infection is rampant. Isolation is also a terrible idea because it would make it much more difficult to get aid to the region—allowing the disease to spread even more quickly.
And consider that people, both volunteer health care workers and citizens, also travel from West Africa to China and India. China has sent 170 health care workers to aid.
Despite highly developed regions in each country, there are also vast numbers of slum dwellers with little access to health care—the perfect breeding ground for Ebola. It is, in fact, perfectly possible that potential new infection locations could already be developing.
Why is Ebola so difficult to Fight? What About Interferons?
To understand the problem you first need to realize that the body fights a viral infection in an entirely different way than it does a bacterial infection.
You’ve probably heard of Interferon A and other versions of interferon that are used to fight viral infections and may have thought they were related to antibiotics such as penicillin—they aren’t.
A bacterium is actually a cell, but a virus is simply a tiny bit of self-replicating material without any cellular structure. There has been a lot of debate as to whether a virus is actually alive. Bacteria are living things, but a virus acts much more like a simple chemical reaction.
Different kinds of antibiotics work in different ways. For example, penicillin actually breaks down the surface of a bacterium, destroying it like puncturing a balloon. Other kinds of antibiotics interfere with the chemical processes inside the bacterial cells.
A simple but inexact way to view the difference between a bacterium and a virus is to understand that bacteria sort of “eat” healthy cells, while a virus gets inside cells and takes parts of the cell to build more copies of the virus until it bursts out of the cell wall and the many replicants spread out to attack new cells.
An interferon works using an entirely different mechanism than an antibiotic. Interferons don’t attack a virus at all, nor do they interfere with the chemical replication process of the virus.
There are three kinds of interferons—alpha, beta, and gamma. All three are complex proteins created by the cells when attacked by a virus. When these proteins are created and released from cells they alter the way genes controlling the immune system work and, in effect, tell the immune system that the body is being attacked by a virus or bacteria.
Thus, interferons are signalling devices used by the body to trigger a defense reaction. They are all replicated from actual cell proteins—that is why they are so rare and expensive.
If a person is already weakened by a disease, he or she may not be able to fight off the attack once the immune system is alerted. Because Ebola kills so rapidly, the body’s defenses can’t build quickly enough to beat the disease even if it gets interferon because it is already weakened at the time of diagnosis.
Even worse, Ebola itself interferes with the immune signalling process and replicates without any interference from the body’s immune system, which is why it develops so rapidly—there is absolutely nothing to slow it down. Interferon isn’t given because it is a cure; it is given because there is nothing else and it won’t do any harm.
Treating Ebola is a matter of keeping the patient strong and hydrated long enough for the immune system to overpower the infection despite this interference. That isn’t easy even in a developed country but in rural Africa it is virtually impossible, which explains why most patients in the U.S. survived and only ten percent of those treated in Africa did.
Treatment and Vaccines—The Grim Reality
• Ebola patients are not infectious unless they have a fever. You can sit next to them, shake hands, share a meal, even a kiss. When they develop a fever they simultaneously begin vomiting and have diarrhea. These symptoms progress quickly and are essentially get out of control very soon.
• Think of the worst flu episode you have ever experienced and that is the starting point for Ebola. Patients need a bathroom where they won’t be injured when they pass out—this often happens. Not only are patients infectious when they have a fever, they simultaneously produce large quantities of bodily fluids, all of which are highly infectious and must not touch any of the caregiver’s skin.
This is similar to treatment of AIDS patients as far as protection of the caregivers is concerned.
According to the WHO, “Ebola is a hemorrhagic fever with symptoms similar to that of extreme radiation exposure. Hemorrhagic refers to blood and a hemorrhagic disease is one which essentially breaks down the blood vessels and blood leaks into the body, lungs, and intestines.”
Protection against Ebola consists of avoiding all contact with those fluids. That’s it, a relatively simple procedure with the exception of removal of the protective gown and gloves—the most dangerous part of the procedure. When treating a patient, someone must supervise both the donning and removal of the protective equipment and the person must be sprayed down with a dilute bleach solution.
Ebola is not an airborne disease. That is, you can’t catch it just by breathing the same air as a patient. A simple N-95 dust mask (which is used for flu patients) is probably sufficient out in the field where separate air sources are not possible (remember there are likely to be a million patients and there simply aren’t that many total isolation suits in the world).
An N-95 mask blocks the tiny droplets that do carry Ebola and which travel about three feet from a patient.
Vaccines
In October, a WHO conference brought together top experts from around the world to discuss the progress in developing Ebola treatments. Two promising vaccines are being tested.
“Two candidate vaccines have clinical-grade vials available for phase one pre-licensure clinical trials,” says the WHO.
GlaxoSmithKline, in collaboration with the U.S. National Institute of Allergy and Infectious Diseases, has developed cAd3-ZEBOV using a chimpanzee-derived adenovirus into which an Ebola virus gene has been added. An adenovirus is a kind of virus without any protective coat and which is responsible for about one in ten cases of serious respiratory infections in children.
A second potential vaccine, rVSV-ZEBOV, developed by the Public Health Agency of Canada and owned by an American company, NewLink Genetics, uses an attenuated or weakened vesicular stomatitis virus, a pathogen found in livestock; again, one of its genes has been replaced with Ebola virus genetic material. A stomatitis virus is simply a virus that causes inflammation of mucous membranes of the mouth. It is not a specific kind of virus but rather a class of diseases, some of which are caused by some viruses.
There is also ZMapp, an experimental drug comprising three chimeric monoclonal antibodies under development as a treatment for Ebola virus disease. The people 
treated in Atlanta with ZMapp walked out of the hospital (although one of the two since became very ill from apparently unrelated causes) using the entire world supply of that promising Ebola medicine. But ZMapp may not actually have been the reason they were cured; supportive efforts may have contributed as much to their survival by giving their bodies enough time to fight the infection.
[Left, researcher conducting a study of the experimental drug ZMapp. Courtesy USAMRIID.]
What you need to know is that there are only two promising vaccines that might protect people against Ebola, and both are being given a rush priority for development and testing. Trials are being conducted in healthy human volunteers to determine first of all whether the vaccines are safe and also to determine the appropriate dosage to produce a reaction.
During the first week of November, the experimental rVSV-ZEBOV vaccine developed by scientists at the Public Health Agency of Canada was approved for human trials. The first trial in West Africa will use healthy health-care workers to see if it is safe and if they develop Ebola antibodies. Trials of rVSV-ZEBOV began in the U.S. in mid-October.
This sort of testing and development being done in a few months would normally take years. Even after the first phase of testing we will only know if the vaccines are safe to give healthy humans; it won’t be until that testing is completed, where vaccinated individuals are exposed to live Ebola virus, will we have any idea if either vaccine is effective in protecting people.
Even if successful, there are major challenges in delivering the medicine to people in Africa, not least of which is the fact that both must be stored at minus eighty degrees Celsius, far below freezing, and that can be extremely difficult in tropic Third World environments.
The following are the steps involved and possible timeline of key expected milestones according to the WHO study:
• October 2014: phase one trials must be started.
• October–November 2014: testing protocols (including those for phase two studies) must be developed.
• October–November 2014: sites in affected countries for phase two-b studies should start.
• November–December 2014: safety data from phase one trials will be known.
• January 2015: Good manufacturing practices vaccine doses will be available for phase two tests. (That means mass-produced quantities using standard procedures rather than laboratory processes handled by trained scientists.)
• January–February 2015: phase two studies approved and begun in affected and non-affected countries.
The CDC website publishes the latest information on drugs to treat Ebola (Ebola virus disease).
Here is the situation as of early October, according to the CDC:
“No FDA-approved vaccine or medicine (that is, an antiviral drug) is available for Ebola. Symptoms of Ebola are treated as they appear. The following basic interventions, when used early, can significantly improve the chances of survival: providing intravenous fluids (IV) and balancing electrolytes (body salts); maintaining oxygen status and blood pressure; treating other infections if they occur. Experimental vaccines and treatments for Ebola are under development, but they have not yet been fully tested for safety or effectiveness.”
Currently the only treatment is supportive care, which is done both to keep the patient comfortable and to give his or her own immune system time to develop defenses.
Adds the WHO: “People who recover from Ebola infection develop antibodies that last for at least ten years, possibly longer. It isn’t known if people who recover are immune for life or if they can become infected with a different species of Ebola. Some people who have recovered from Ebola have developed long-term complications, such as joint and vision problems.”
Who Am I?
At this point, I should probably make a few comments about my qualifications to write about such a complex medical situation.
I have some basic training in epidemology and virology and have been covering the Ebola outbreak via WHO and CDC press conferences and other sources for “Newsblaze,” the online daily newspaper, since the outbreak began. I recently wrote a Kindle book, “Ebola Protecting Your Family—What You Need to Know NOW!”
In addition, I am a retired emergency management coordinator (twenty years’ experience) and trained in both radiologic and biohazard detection, containment, and decontamination which involves almost exactly the same protective procedures as the medical isolation and protective gear required for Ebola.
I was also recently involved in a brief practice training drill for containing a possible contagion outbreak in Pennsylvania—obviously a preparedness test for a possible Ebola outbreak.
To sum up, you as an individual in a developed country are not in any direct danger from an Ebola infection. You can use hospitals where Ebola patients were treated, ride taxis, airplanes, and subway cars they used, and live in an apartment they used to occupy.
But the world, especially China and India, as well as the rest of Africa, is in extreme danger from Ebola. As the disease spreads, it will threaten the stability of governments and infrastructures. It could even eventually threaten advanced countries if neglected.
If the advanced world doesn’t take fast and drastic action (much more than various governments have already proposed), this could be that end-of-the-world-as-we-know-it epidemic, killing hundreds of millions, or billions of people. On the other hand, piling on resources and personnel immediately will stop this deadly epidemic in its path. 
John McCormick is a trained physicist, science/technology journalist, and widely-published author with more than 17,000 bylines to his credit. He is a member of The National Press Club and the AAAS. His full bibliography can be accessed online.
