Breaking Down Science, Step by Step

The Gigantic Ebola Outbreak FAQ

There is a lot of (understandable) panic surrounding the Ebola outbreak currently ravaging West Africa, but what exactly do we know about it so far ?

Earlier this week I posted an infographic that I fear shovelled coal into the engine of the hype train riding on the tracks laid by the largest outbreak of Ebola ever recorded. To correct this, I have scoured pretty much every scientific publication and reliable outlet I could find to get as much information in one place as possible.


What is Ebola ?

The Ebola is a virus, and like most viruses it can only reproduce inside the cells of your body. Ebola comes in five flavours, and none of them are cherry.

In order of dangerousness-

5. Reston. This is the only Ebola virus to have first been discovered outside of Africa, appearing in Washington D.C. The main victims of this outbreak were Crab eating Macacques housed in a Laboratory. Over a period of three months, a third of the monkeys died from the virus. Whilst it seems like some of the researchers working with them were exposed to the virus, none of them actually showed any signs of disease. It turns out to have originated from the Phillipines, and has since then shown up in pigs. But there are no records of any humans having been even made the slightest bit ill by this virus.


4. Tai forest. This one is a real problem for the chimpanzees living in the Tai national park, reducing at least one troop of chimpanzees from 80 to 32, and it's thought they got it from eating monkeys infected with the virus. One of the researchers looking after these chimpanzees became infected, but they recovered, and were the only ever human case for this disease.

3. Bundibugyo. This is a relatively recent discovery, having emerged in 2007 in Uganda. So far, it's killed 66 people since it was first discovered. In the initial outbreak, it had a case fatality rate of 25%, but it recently re-emerged in 2012 with a 51% case fatality rate.


2. Sudan. In 1976, this virus was found in Sudan, although it has crossed into Uganda as well. It has a case fatality rate of about 53%, and the last case reported was in 2011.

1. Zaire. This is the big one, the most deadly of the Ebola viruses. When it was first discovered in 1976, it had an 88% case fatality rate. It's killed the most people, and is the Ebola virus responsible for this latest outbreak ravaging West Africa.


What makes the Ebola virus dangerous ?

You know how you have blood vessels ? The smallest blood vessels that transport blood and immune cells throughout the body are called capillaries, and Ebola is not good for them.


In normal immune responses, these capillaries can become "permeable", to let the immune cells get out of these vessels to go and fight pathogens. It's a nice little system, until Ebola virus comes along and messes it all up.

You see, when Ebola infects immune cells cells, it can cause them to create "virus like particles", and to secrete a ton of chemical messages telling the capillaries to get leaky. This lets the virus escape from the bloodstream and rapidly infect even more cells.


But then these leaky capillaries start to spill out blood. At first, this blood build up shows up as rashes, but as the blood forms pools within the body, they clot together. Since the blood is leaking everywhere, it doesn't get to all of it's intended destinations, leaving clumps of cells to suffocate and die off. In this situation, the immune system should be able to spot the damage, and send in cells to find out what's going on, but this is where Ebola plays its next trick.

The virus messes around with the immune system, hiding itself inside the very cells designed to recognise it, and killing them off quickly and efficiently. Even if some of the immune cells do notice the damage it's causing, the breakdown of the circulatory system makes it really hard for them to get to where they need to be.


So basically, the virus breaks down the basic infrastructure of the body, causing blood and fluids to be leaked out of the circulatory system, causing cells to die from oxygen starvation, and massive fluid loss from vomiting and diarrhoea. Did I mention that this process causes blood to leak out of your orifices ?

This is where it gets nasty, because it causes blood to enter the gut, causing the vomiting of blood, and in extreme cases sufferers can bleed from their eyes. Ebola is gruesome, and it's fast. It has an incubation period of about 1-25 days, and death follows (on average) after ten days.


Wow, that's nasty. How do you get Ebola ?

Many Ebola outbreaks began when people handled dead apes. For a while, researchers made the obvious connection, that humans tend to get it from apes. But a good virus tends not to kill it's host, and Ebola fucks up apes just as badly as it does humans.


The current evidence indicates that bats are the main host of Ebola, and they pass it on to other animals, such as apes antelope, deer, and porcupines which then pass it onto humans. If you get in contact with the blood or the carcass of an infected animal, you can get the virus.

The virus can pass from human to human through contact with our various gross secretions, such as saliva, blood, and pretty much any other bodily fluid you can care to mention. These secretions can get on bedding and furniture, so avoid handling those as well.


It isn't airborne in the way that influenza is, but if you get close enough to a sufferer to feel the flecks of spittle from their coughing fit hit your face, you're gonna have a bad time.

There have been studies that show that the virus can still show up in a man's semen up to six weeks after he's recovered from the infection. But that study was performed under laboratory conditions, and we don't really know whether he had enough of the virus to actually infect another person. So it's conceivable that an Ebola survivor could still infect people, but I haven't yet found real world examples of this occurring.


The rule of thumb currently goes that you cannot get Ebola from healthy looking people. It's only when sufferers show signs of sickness that you can be sure they are infectious, and to keep away.

Okay, so what's the deal with this latest outbreak?

This latest outbreak is currently the largest outbreak of Ebola since it was discovered, with an estimated 1048 cases spread across three countries in West Africa, and 632 deaths. For reference, the next largest outbreak was in Uganda in the year 2000, caused by the Sudan strain of Ebola, which ended up infecting 425 people, of whom 224 died. The deadliest outbreak was due to the Zaire strain in Democratic republic of Congo, which killed 30 more people.


This outbreak is huge.

How did it start?

A 2 yr old child was the first recorded victim of this outbreak, with symptoms of vomiting and fever emerging on the 2nd of December, before passing away on the 6th. Her mother developed the disease not long afterwards passing on the 11th, followed by her 3 yr old sister on the 29th. The grandmother died on the 1st of January. The nurse and the midwife who cared for them became ill in the latter part of that month. The midwife managed to get to a hospital in Gueckedougou before she passed, and in the process infected the family member who took her there.


The doctor who attended her, and other patients in Gueckedougou succumbed to the illness, and was transferred to another hospital in the town of Macenta. After he died his funeral was held in the city of Kissidougou. In the course of his journey, both pre and post mortem, he managed to start outbreak clusters in Macenta and Kissidougou.

On March the 10th the public centres at Macenta and Gueckedou alerted the Guinean Ministry of Health about this mysterious fatal disease, whose symptoms were diarrhoea, vomiting and fever.


Two days later, Medecins sans Frontieres were on the case. Blood samples from patients were collected, and sent to the Insititut Pasteur in Lyon, where they discovered to the presence of Zaire Ebola virus.

One March 23rd, the World Health Organisation (WHO) issued the first alert about the outbreak.


Why did it take them so damn long to recognise Ebola ?

You have to remember that the main symptoms that this particular strain of Ebola showed were diarrhoea , fever and vomiting. Those aren't unique symptoms. They could be from Yellow fever, Malaria and even Lassa fever.


There wasn't any of that distinctive eye-bleeding that I talked about earlier. It would take extensive lab tests to discover that it actually was Ebola.

Nobody was expecting it. Ebola was a disease of Central Africa. All they had in West Africa was the Tai Forest virus, which would only really scare you if you happened to be a chimpanzee.


Where did it come from ?

Early on in the outbreak, it was suspected that the Zaire virus responsible for this outbreak had come from Central Africa. However, genetic evidence shows that whilst this strain is related to the Zaire virus, the relationship wasn't as close as you'd expect had it actually come from the Congo.


Fruit bats are thought to be the natural hosts for Ebola. Unfortunately, no-one really knows which species of fruit bat are the carriers, or how they spread it to other animals besides getting eaten by them. There are researchers out in the field who are trying to work out who the natural hosts of this Ebola strain actually are.

Some evidence has recently emerged that Ebola may have been lurking in Guinea for years. Researchers based at the US Army Medical Research Institute of Infectious Diseases have been tracking disease outbreaks in West Africa for some time. As part of their research, they took blood from patients.


If the patients had at some point been exposed to Ebola, then you would see antibodies to the virus in their blood-stream. No one had thought to test for Ebola before. So when this latest outbreak occurred, they went back to test some of those blood samples. They found antibodies against Zaire-Ebola in 9% of samples between 2006 and 2008. However these tests aren't completely reliable, and it'll take more work to confirm these results


What have the authorities been doing to contain this outbreak ?

A number of organisations have mobilised to contain this outbreak in addition to the Guinean Ministry of Health, such as Medecins Sans Frontieres and the International Federation for the Red Cross and Red Crescent and the WHO. Some of the strategies they have been using to combat this outbreak are listed below.

  • Educate people about Ebola.People need to be told how to protect themselves and their families from Ebola. This is the biggest, and probably the hardest intervention to implement. This strategy should involve religious and community leaders, because allies on the ground are so essential to fighting disease outbreaks and defusing fears.
  • Encourage them to report on new cases. Researchers need to gather as much information about this outbreak as it occurs. New victims of the disease need to be tracked down as quickly as possible, to stop them from spreading the disease, to find out where they got it from, and to hopefully get them some treatment. This cannot be done without the help, or at least the permission of the wider community.
  • Isolation wards. Infectious patients need to be isolated from the rest of the community to stop them from passing on the disease. The medics who treat them must wear protective gear to minimise the risk that they'll pick up the disease while they work.
  • Hand washing. This is pretty standard for any outbreak. After handling any material that has the slightest chance of harbouring the virus, hands must be washed thoroughly.
  • Establishing a mobile laboratory to help quickly identify patients- There is a huge need to confirm cases of Ebola, which can only really be done using laboratory tests. These tests allow for people with Ebola to be discovered before they exhibit any symptoms, allowing them to be isolated and treated before they become infectious. The ability to rule out patients also takes some of the pressure from the medical teams.
  • Provide treatment where they can. At the moment, the main treatment for Ebola is hydration therapy, to replace all of the liquids being lost from patients. There are very few treatments against Ebola with any proven real-life efficacy. Some researchers are using this outbreak to plug their pet cures, but keep in mind that none of them are yet ready for prime time.
  • The government has banned the eating of bats and other game meat. This is pretty much a no-brainer, since the disease is likely to have originated in bats, or other animals consumed as "bush meat".
  • Assisting in the burying of the dead. Dead bodies are a huge hazard, which many outbreaks stemming from corpses being handled. There is a need for protective gear, and to ensure that there is no ongoing threat from the buried people.
  • Funerals have been outlawed. This goes hand in hand with the last point. Funerals have acted as mass propagation events for the outbreak. The first problem is the need to move the bodies from the place of death to the place of burial, followed by the need for the family to clean and dress the body. This is what can lead to Ebola jumping from different towns, and establishing new clusters of infection.

So did that stop the outbreak ?

Ehhh… it looked like it.

The responders may have been caught on the back foot, but towards the end of April, it had begun to look like the virus had been contained.


There had been some confirmed cases in Liberia, but the sufferers and their contacts were tracked down and isolated quickly. There had been worrying reports coming in from Sierra Leone, but laboratory tests showed that they weren't Ebola.

So for a time towards the end of April, it looked like this outbreak had largely been confined to Guinea.


Was it ?

Oh, hell no.

On the 25th of May, the WHO confirmed that the virus had spread to Sierra Leone. Then, Liberia discovered a new case of Ebola that had jumped over from Sierra Leone.


The drive for education about Ebola turned out to have not exactly worked. The violation of funereal rites is a sticking point for rural communities desperate to see their loved ones buried with respect. There have been reports of riot police firing tear gas at crowds to stop them from recovering bodies of family members.

Furthermore, people who are working to fight the outbreak can't expect a warm welcome wherever they go. There have been reports of responders being attacked by locals


Attacks ? But they're only trying to help !

Where disaster goes, panic and misinformation follow. This outbreak is no different. People go into the isolation tents, and they don't come out. Who knows what actually goes on inside.


There are some who believe that it's all a conspiracy, an excuse for the government to quietly murder them with their consent. Ebola doesn't exist, and if you believe the lie, you're letting the government kill you.

Angry crowds have descended on treatment centres believing that they were the source of the scourge, scattering the occupants. Villages in Guinea and Liberia have blockaded roads and chased off medical response units with machetes and stones. Treatment centres are seen as death camps, and avoided (pardon the phrase) like the plague.


Then there are the people who do believe in Ebola. There are stories circulating that it's been caused by witchcraft, and that people who "survive" are zombies. There are instances of survivors returning to their families, only to be shunned and exiled from their communities for fear they will spread the virus.

Then there are the ones who simply accept that they have a death sentence, and don't bother to go to the medical authorities, and prefer to spend their last moments with their families. All of these factors work to increase the stigma associated with turning up to the medical tents for help, because even if it isn't certain death, it would lead to shame and isolation.


This leads to a rise in the "invisible infected". These people don't end up factoring into the WHO numbers. They could freely infect anyone they're in contact with, causing new clusters of the disease to appear seemingly ou of nowhere.

So is that why this outbreak is out of control?

It's one major factor. But the lack of infrastructure, both medical and transport are also big problems. Then you have to deal with the porous borders between Liberia and Sierra Leone, and the needs to co-ordinate a response across all three of them. The teams fighting this outbreak also lack resources and funding, which is probably a more major concern.


This is all very nasty, but how does it affect me ?

Oh, how you disappoint me. It's easy to look past the genuine human suffering occurring when the only thing you're worried about is whether this disease shows up on your own doorstep.


There is always the chance of an Ebola pandemic with any outbreak. The bigger the outbreak, the bigger the chance someone will end up taking it away on a plane to some other country, and that country might be yours. I'm not going to tell you that there is no threat here, because there plainly is. But at the time of writing , there have not yet been any recorded instances outside of West Africa. If there are only small trickles of infected entering other countries with the disease, it'll be pretty straightforward to contain. Now that we know what to look for, it's unlikely it will gain much ground outside the countries that already harbour it.

But think about this. We can't even get people to vaccinate. Our health systems have never had to cope with Ebola. Our hygiene techniques still haven't stopped MRSA from exploding in periodic outbreaks. We cannot be complacent about the ramifications of Ebola escaping West Africa.


I know we all think we'd do the noble thing if the circumstance were to arise. Up until the men in white coats threaten to take us away to the death tent just because of a bout of vomiting and diarrhoea.

"That could've been last nights chipotle you fascist fucks ! No, don't take me to where the Ebola people are, I beg you, I don't wanna go NOOOOoooooooooooooooooo!!"


But even if it never goes global, that doesn't mean we're free to turn a blind eye to it. Even though these people live far away, their lives still matter. From the two year old girl and her sister who first got the virus, to the Doctors and Health workers giving their lives right now.

Is there anything I can do ?

Well, perhaps you could support the charities who are putting in a lot of work to help stop these outbreaks.


Medecins sans Frontieres and the International Federation of the Red Cross and Red Crescent have both been have been on the front line of this outbreak, and will be there for the duration. They really need your help.

I've posted a continuation of this story here



Pathogenesis of Viral Hemorrhagic Fevers, by Slobodan Pessler and David H. Walker in the Annual Review of Pathology: Mechanisms of Disease


Ebola in West Africa: gaining community trust and confidence, published in the Lancet.

Ebola Viral Disease Outbreak- West Africa 2014, Morbidity and Mortality Weekly Report (June 24 2014) published by the Centres for Disease Control.


Ebola emergency meeting establishes a new control centre, published in the Lancet

Ebola virus disease in Guinea (23 March 2014) published by the World Health Organisation


Emergence of Zaire Ebola Virus Disease in Guinea - Preliminary Report by Sylvain Baize et al ,Published by the New England Journal of Medicine

The 2014 Ebola virus disease outbreak in West Africa, by Derek Gatherer, in the Journal of General Virology


Sierra Leone samples: Ebola evidence in West Africa in 2006

Ebola- A Growing Threat ? by Heinz Feldmann in the New England Journal of Medicine


Ebola Survivor Shunned as a Zombie Joins Fight Against Disease by Pauline Bax, published in Bloomberg

Ebola snakes and witchcraft: Stopping the deadly disease in its tracks in West Africa, by Cristina Estrada in International Federation of Red Cross and Red Crescent Societies News Blog.


Image credits (In order of appearence)

Stuffed Ebola by Sage Ross hosted on

Transmission Electron Micrograph of an Ebola virus taken by CDC microbiologist Cynthia Goldsmith, hosted on


Seychelles Fruit Bat by Marion Schneider & Christoph Aistleitner, hosted on

This 1976 photograph shows two nurses standing in front of Ebola case #3, who was treated, and later died at Ngaliema Hospital, in Kinshasa, Zaire. Credited to Lyle Conrad of the CDC, hosted on

Share This Story