Category Archives: Ebola

Can Dogs Transmit Ebola? And, should Excalibur be put down? they put down Excalibur.

UPDATE: They killed the dog.

UPDATE: I’m adding this here because it is my current post on Ebola. Thomas Eric Duncan, the person who became symptomatic with Ebola in Dallas, had died at the Texas Health Presbyterian Hospital (according to news alerts).

A nurse’s assistant in Spain caring for Spanish nationals returned with Ebola from West Africa contracted the disease, gaining the dubious distinction of being the first person to be infected with Ebola outside of that disease’s normal range in West Africa, Central Africa and western East Africa. There is speculation that she contracted the disease by contacting the outside surfaces of her own protective gear, which is exactly what I’ve speculated to be a likely cause of infection in health care workers. This is not certain, however.

Members of her family and others, including additional health care workers, are in quarantine. There is evidence that the hospital procedures were inadequate to keep a lid on Ebola in this context, and nurse’s unions and others are protesting and demanding change.

Meanwhile, the Spanish government has claimed that there is “scientific evidence” that dogs can transmit Ebola, so Excalibur, the nurse’s family dog, will be euthanized and incinerated. People have gone to the streets to safe the dog.

So, can dogs get, or transmit if they get it, Ebola? Short answer: Yes, and probably not. Here’s my thinking on this, and some information.

1) Pick a random species, or to make it easier, pick a random mammal, and test to see if it can transmit a disease known in humans. It is unlikely to be the case because diseases are to some degree adapted to exist in certain hosts, and host vary, well, by species. So it seems unlikely.

2) On the other hand, Ebola seems to be able to infect a very wide range of mammals. Ebola resides in multiple species of fruit bats (though maybe not uniformly or equally well). A range of mammals seen to be suitable intermediates between fruit bats and humans. The mammals known to be able to harbor Ebola are diverse. It isn’t like only primates can be infected. So, it seems quite possible.

3) On the third hand, I’ve never heard of dogs being addressed as an issue in the current crisis in West Africa or during prior outbreaks. One would think that if dogs were a concern this would have been mentioned by someone some time.

4) On the fourth hand, dogs in Central Africa are less likely to be house dogs, hanging around with the family on the couch, and more likely to be working dogs that spend all their time outdoors. A Spanish family pet may have hung around on the sick bed with an ill individual. I don’t know about dogs in West African cities. By the way, you have to go look to see what the story with dogs there is, and it may within that context. I’ve noticed that westerners tend to have a rather monolithic view of how humans “elsewhere” (especially the “third world”) relate to their dogs, based on a concept we hold of them, not based on actual knowledge. How dogs fit in with humans from place to place and time to time varies.

5) I’ve read a good amount of the peer reviewed literature on Ebola and I can not recall anything about dogs.

5) But … A quick check of Google Scholar did come up with one study. From the abstract:

During the 2001–2002 outbreak in Gabon, we observed that several dogs were highly exposed to Ebola virus by eating infected dead animals. To examine whether these animals became infected with Ebola virus, we sampled 439 dogs and screened them by Ebola virus–specific immunoglobulin (Ig) G assay, antigen detection, and viral polymerase chain reaction amplification. Seven (8.9%) of 79 samples from the 2 main towns, 15 (15.2%) of 14 the 99 samples from Mekambo, and 40 (25.2%) of 159 samples from villages in the Ebola virus–epidemic area had detectable Ebola virus–IgG, compared to only 2 (2%) of 102 samples from France. Among dogs from villages with both infected animal carcasses and human cases, seroprevalence was 31.8%. A significant positive direct association existed between seroprevalence and the distances to the Ebola virus–epidemic area. This study suggests that dogs can be infected by Ebola virus and that the putative infection is asymptomatic.

I’ve not looked further at the literature. This study suggests, unsurprisingly (see point 2 above) that dogs can harbor the virus. However, they don’t seem to be symptomatic. Therefore, spread from a dog seems unlikely. I would think the dog could be kenneled for a few weeks, rather than being put down.

Two Odd Examples of Pre Ebola "Ebola"

I used Google N-gram Viewer to inspect the occurrence of the word “Ebola” in the Google-indexed literature. A few instances of Ebola came up earlier than the disease being known, so I figured they were references to the place name in Zaire/Congo, after which the disease is named. And that was in fact the case. But, of handful of early instances I checked out, two were interesting.

The Ngram is above. Note that I have smoothing set to zero, which I recommend, and I’ve got the date set for early on in the use of the term so pre-disease uses are more visible.

The two interesting instances I wanted to show you are ..

1) An Okapi at the Paris Zoo named Ebola, allegedly the first captive born Okapi to survive in a zoo.

Screen Shot 2014-09-11 at 10.41.19 PM

The other is a bit stranger. Have a look:

Screen Shot 2014-09-11 at 10.44.16 PM

See the yellow highlight? This (and the Okapi picture) are screen grabs of what Google Books give you when you search for a word or term. Here, “China” in funny Gothic looking script was recognized by the scanner as “Ebola.” You can kind of see how that would happen. Not really. But it happened.

Two Ways Hollywood and Literature Have Confused The Ebola Problem

According to popular literature (some fiction, some not) and movies, Ebola can cause havoc, infecting thousands of people, killing over half of them, and threatening an entire nation if it were to become airborne. Turns out that’s not true. Ebola can do all those things without becoming airborne. In several nations.

The confusion caused by this misconception is further enhanced in a more subtle way. Since the Hollywood version of Ebola (or some other similar disease) indicates that it is dangerous because it becomes airborne, we see constant claims today on the Internet that Ebola must be airborne because it is out of control in West Africa. And, of course, we see claims that it is only a matter of time before it becomes airborne. But an examination of the disease from an evolutionary perspective suggests that this is extremely unlikely. It is almost as though people have to believe that Ebola will eventually become airborne (or already is) to take it seriously. It wont’ become airborne. You must still take it seriously.

So that is the first area of confusion, about what Ebola is and what it does and does not do.

To this confusion, by the way, we may add the already mentioned hyperbolic reaction to Ebola, often of a rather tin-hat variety and the equally incorrect hyperskepticism that has made claims like Ebola is not that big of a deal because it is not malaria. That is also demonstrably false.

The second area of confusion is what is normally done when something like Ebola shows up in the US, as it has in Dallas, Texas. The Hollywood and Literature version is that a big silver truck shows up at the site, people with protective gear jump out of the back, individuals are taken away to Level 4 containment facilities that are handily available nearby, the site is sterilized using high tech devices (or imploded or burned down with flame throwers?), and if there are a lot of possibly infected people, everybody is quickly rounded up and moved in large green trucks to a containment camp run by the Army, with Morgan Freeman in charge whom you think at first is a nice guy but turns out to be evil.

Well, some of that is sort of happening, but slowly and clumsily and with no has-mat suits and no containment camp. As I write this I’m watching the live briefing on Ebola in Dallas. We have just learned that pretty soon some guys are going to go over to the apartment where the family of the patient lives. They will do the laundry when they get there because there might be Ebola kooties on the sheets and pillows. The CDC went grocery shopping for them, and they are being told they can’t leave. So in a way this is a little like what Hollywood says would happen, but with much, much lower production value and pretty much as a post-hoc set of reactions rather than a clear plan always in place just in case.

We are also learning at the news conference that there is not a current plan for where to take a second or third Ebola case. No playbook in place. Having said that, the authorities are confident that they can handle the problem.

None of this is surprising. After all, fiction is fiction. That’s why they call it fiction. What is also not surprising, but disappointing, is the low level of thought behind the questions the press are asking, and the highly unprofessional approach taken by some reporters. Pro tip: Don’t ask only dumb questions, or questions that have already been answered, then be all mad and stuff when the press conference ends sooner than you thought it should.

More on Ebola:

Ebola in Dallas Texas: Is our response adequate?

First, let’s look at the situation in West Africa, because that is way more important than anything going on in the US right now. The WHO has said two things about this. First, if there is not a full intervention, there may be hundreds of thousands or even millions of cases of Ebola several months from now (cumulatively). Second, with full intervention they can stop this epidemic.

What is full intervention? They say that full intervention is the development and manufacture of an effective vaccine, and the deployment of that vaccine to a very large percentage of the affected population.

Putting this another way, the current response has been inadequate, and while it can be improved, it can’t be made adequate. Things are pretty bad, are going to get enormously worse, and there is little hope for any other outcome, unless full deployment of a vaccine that does not exist over the next six months is realistic.

Now let’s look at the US. Public health officials and public health experts have been saying the same thing for months. Don’t worry about an Ebola outbreak in the US. We can handle it. We know what we are doing, and we have the systems in place to take care of this. So just don’t worry.

I’m going to tell you now why this is probably both true and untrue.

It is probably true at the large scale. We are not going to have an outbreak of Ebola in the US that involves hundreds of people getting the disease. Probably not even dozens. But, it is not true that we have the capacity to fully handle Ebola coming to the US in the way most people assume this is meant. It is very possible for Ebola to some to the US and make a bunch of people sick with about half of them dying. How many is a bunch? Five, maybe eight, something along those lines, but possibly a few times, in a few places, adding to a couple of dozen. (Totally guessing here, feel free to make your own guess.) That may not happen at all, but given the current situation it is absolutely possible. However, it is not necessary. If our public health system was truly able to handle an Ebola intrusion, the only people who would have Ebola in the US would be those who arrive with it, and possibly a very small number of additional people, not a bunch. In other words, unless changes are made, the inadequacy of our system, said to be fully adequate, will allow several people in the US to become ill, some will die, over the next year.

Here is why.

First, consider the travel problem, which is probably the smallest part of this. When Patient X came to Dallas with no Ebola symptoms, he was almost certainly not a risk. But he did get on an aircraft with the disease, and took a long trip the US. If this event happens 100 times over the next several months, how many times will the patient become symptomatic on the plane, possibly exposing others? 10% of the time? 5%? 20%? Hard to say, but often enough that over the next several months hundreds of travelers and airline workers will be exposed, but, the chance of them contracting the disease is low. So, with the current expanding outbreak and current policies, a very small number of people may get Ebola in a system that claims to be totally able to handle it. That’s small change compared to what is going on in West Africa, and it is probably the least of our worries here in First World Land.

Second, we have the problem of reporting and identification. Patient X became symptomatic and then for something like a day did not seek medical help, during which time various individuals were potentially exposed. Again, since Ebola is not airborne, the chances of them getting the disease is low, but it is real. The problem is that when people get sick, there is almost always going to be a window of time from a few hours to a couple of days during which the most prepared health care system in the world has no control over what happens because the person does not show up at a hospital or clinic. There may be no way to avoid this, but the risks can be reduced. If the West African epidemic continues members of the communities that overlap between the US and West Africa will be at risk, albeit low risk, of exposure to those who travel back and forth on a regular basis. What needs to happen is that those communities take special care to address this issue internally. All it is going to take is one or two Americans catching the disease from a person living part time in West Africa to shut down air connections between the two regions. If we want to avoid this, there needs to be self-monitoring in the communities.

Third, we have the unconscionable thing that happened in Dallas. A patient who had been in Liberia showed up with Ebola like symptoms in a hospital and was sent home. Holy moly. Why did that happen? Well if you’ve been recently in the hospital for anything that required testing and such, you may already know. Hospitals and clinics, but especially emergency rooms, are run like those steak houses that became popular back in the 1980s. You arrive at the steak house, and a nice person with a big smile seats your group. Then a server comes over and takes drink orders. A second server brings the drinks. A third server comes by for your meal order. A fourth server brings the appetizers, and a fifth server brings your meal. Eventually somebody comes by with the check. (Remember those?)

In an emergency room, there will probably be a physician taking care of you but all the tests that are run are done by different individuals, if there is some kind of treatment you need, the person who cues you in on that (tells you how to take the pill or use the device they are going to give you) is different still. The person who checks you out is different still. What is the possibility that a concern you address to the physical will be responded to by that physician later during your visit? It depends on how fast the person who check you out and sends you home arrives on the scene. Maybe 50–50.

That is probably how Patient X was let go with Ebola. The system has too many places to break. How likely is that to happen again in other emergency rooms or clinics in the US? Not zero.

So, the bad news is that our system does not really put the lid on Patient Zeros that may show up in clinics or hospital, reliably. The system we have been assured would not allow an outbreak probably won’t allow an outbreak, but it may well allow dozens of people to be needlessly exposed, among whom some may contract the disease.

Now here’s the good news. It is said (though the information is spotty) that between 80–100 people who may have had even minimal contact with Patient X are being checked twice a day for fever, and a smaller number are being looked at more closely, even quarantined. The several schools attended by some kids Patient X had contact with are being sterilized. And so on. Frankly, this is more than necessary, but that’s irrelevant. If you only have a few tiny “hot zones” (in this case, one, and not that hot) an abundance of caution is not overkill. If over-cautious reactions eventually emerge whenever an Ebola patient shows up in the US, the larger scale outbreak will be avoided. But the handful of people initially at risk will not be safe by virtue of our system.

Perhaps that is unavoidable, but I think most people will look at the Dallas event and say that sending the patient home clearly should not have happened, and now every hospital and clinic in the country will be extra cautious. Like, remember that one time a surgeon accidentally amputated the wrong leg, and after that one time, it never happened ever again anywhere?

What, you don’t remember that? Hmm… me neither.

(Also, consider this: Imagine implementing the level of caution now being implemented in Dallas in the affected areas of West Africa? Can you imagine implementing this only half way, or a quarter of the effort? That would a) stop Ebola and b) be impossible. That is why the outbreak continues there. We have a lot to be thankful here in the US.)

Conclusion: The communities that have regular interaction with the affected countries are already in many cases somewhat organized as communities. These communities need to develop humane and thoughtful ways of making sure travelers are properly watched after. Everyone who works in any clinic or hospital has to double check what they are doing and not mess up again. The initial conditions that led to the current situation in Dallas are going to become more common over time.

And, remember, so far everything in Dallas is under control, but it will take 27 days to be sure (the incubation period is about 27 days, despite the “21 day” number you keep hearing). Also, while Ebola can manifest in an infected patient as quickly as two days after exposure, it is more typical to show up 8-10 days later. So the first week to 10 days of October is a fairly likely time, perhaps, to see a second case in Dallas, if there is in fact, further infection.

More on Ebola:

Ebola Will Not Become Airborne And Here Is Why

This discussion has been going on for some time, and a handful of recent events have prompted me to jump into it (beyond a simple comment or two). First, I saw a bunch of yammering among various biology teachers about this topic. Then Michael Osterholm wrote a well intentioned but seemingly deeply flawed opinion at the New York Times, then Dina Fine Maron wrote an excellent piece at Scientific American deconstructing Osterholm’s piece, then the latter two (and more) were summarized and expanded on in a post by Ann Reid at the NCSE.

Here, I will expand on this by applying first principles from evolutionary theory, organizing our thoughts in Tinbergenesque Terms.

There are four categories of reasons that Ebola won’t go airborne. I’m going farther out on a limb here than most others, who say things like “it is possible, but…” Imma say it just isn’t going to happen. Technically, over time, the Sus lineage of mammals (pigs) could give rise to a flying form, like what happened with some earlier lineage of mammal that gave rise to bats. So what I’m really saying is that Ebola will go airborne when pigs fly. Both are possible. But if that is what you really think of as “possible” instead of just “no, it won’t happen” than you may need to calibrate and stop buying those lottery tickets!

Here is why Ebola won’t go airborne.

First, diseases in general, including viruses, do change which species they infect sometimes, and they change in virulence and the exact effects on the host, but they really don’t change their mode of transmission. At the largest evolutionary scale there have been some novelties, obviously (or there would be no variation!). I am pretty sure many of the influenza viruses are not transmitted through the air, but the only ones we bother to name and study do, and are a subset of a larger group that transmits via water. I may have that wrong (going on old personal communications here) but if I am wrong that just crosses off Influenza as a virus that changed mode of transmission. Ebola is in a large group of viruses that are actually found in plants. Obviously, there was a change in transmission at the origin of Ebola. But really, this does not happen very often. If you can think of examples please tell me. (For a non virus example, Malaria is transmitted the same way all the time even if it changes (rarely) which species it affects or otherwise evolves like crazy to stay ahead of interventions.)

In short, we expect strong phylogenetic inertia in mode of transmission.

Second, there is no in place mechanism, probably. Ebola does not infect the tissues it would need to infect to make its way into a sneeze or cough. That would require a major change.

Third, developmentally, the first step in a virus’s life cycle is getting itself into a cell. Airborne viruses need to have a key that matches a lock on the outside of respiratory tissues. So Ebola not only lacks the means for getting out through a sneeze or cough, it also lacks the ability to do much if it did.

Fourth, it is not adaptive. Yes, a virus can mutate to do something stupid and maybe get a Darwin Award, but the chances are at least somewhat reduced. Ebola is very deadly in humans. Humans and the animal vectors that may stand between fruit bats (the likely wild host) and humans are not good hosts for Ebola. The chances of Ebola evolving to infect an unsuitable host are reduced.

Phylogenetically unlikely, mechanistically unlikely, ontogenetically unlikely, adaptively unlikely. Evolution is like baseball but slightly different. Four Tinbergen Strikes and you are out.

Now, the usual arguments in favor of Ebola doing the Hollywood thing rely on references to other viruses, like Influenza. Well, Influenza is way different from Ebola in its reproduction. It has a whole way of evolving that Ebola does not have. In fact, the differences is greater than, potentially (and rarely, but not never) the difference between evolution under sexual reproduction and evolution under simple replication. If two different Influenza strains infect the same cell, they can recombine (reassortment) to make an entirely novel never before seen Influenza. That is a very big deal and is thought to be the primary mechanism for the evolution of novel dangerous flu strains. Ebola does not do that. Ebola can’t do that.

Ebola does not do that. That thing Influenza does.

I said that twice. Now I’ll say it another way. Using Influenza evolution as a model for Ebola evolution is like using Primate Behavior as a model for Sea Slug Behavior. In other words, it does not fit.

Will Ebola go airborne? No.

ADDENDUM

I’m adding a bit more because some are still missing the point. This is an analogy that I think might be helpful

Cars fly, and airplanes drive around on the ground. Ebola can possibly be transmitted across space in a closed room from one person to another, and you can catch a flu by having someone with the flu bleed directly into your nose*.

But really, airplanes are vehicles designed to fly, they only drive around on the ground a little. They have wings, special engines, an overall shape and design that is adapted to flight. But really, cars only fly into the air now and then, and it is generally an accident.

An airborne virus replicates in high numbers in respiratory tissues, and causes the lysing (or some other process) of cells to allow itself out into mucous tissues. It is able to survive in mucous tissues, and then it is able to survive in aerosolized droplets. An aerosolized droplet is not a bit of bodily fluid cast into the air, it is not a drop of blood shed from a wound or bleeding eyeball, or a loogie. It is a bunch of liquid (mainly water) molecules coherent at a size sufficiently small that air currents are more important then gravity, so it becomes part of the atmosphere, and a virus may or may not be residing in it. Then, and airborne virus needs to have the external morphology that links up with a receptor site on respiratory cells in the individual subject to infection, and then, it reproduces mainly in that tissue.

Ebola is none of these things, except possibly one. Ebola is known to survive in mucous tissue for some time after it has left an infected individual. This is not the same as surviving in an aerosolized droplet, but it indicates the possibility. But to go back to the car-airplane analogy, that is a bit like saying that some cars fly farther when they leave the road during an accident.

The distinction is very important. Jane, commenter below, has oddly implied that I’m not taking Ebola seriously. I would like to point out that I may have been the only person to complain about and argue against the trope that Ebola is not so bad because it is not Malaria. I may also be one of the few bloggers writing about Ebola who has lived in Ebola country, doing health care work, and who has actually worked on the problem of the natural reservoir and contributed to it. I am also one of the few people writing now who has pointed out that even though most people with Ebola are in a few African countries, where this needs to be taken very seriously, that it is also true that those communities, in West Africa, are global. This is how my neighbor, Patrick, managed to die of Ebola. He was an American who also worked for the Liberian government, and was in Liberia taking care of his sister, who died of the disease. His wife and family are here, in my town. Ebola affects communities that are not separate from those who have the privilege of being able to muse about it. And here is where the distinction becomes multi-dimensional. All the talk about airborne transmission is not scientifically grounded, and it is a distraction. But saying that it will not become airborne is not saying that it is not a horrible disease that is highly infectious and has pandemic potential. This, the nuances of the epidemiology of Ebola, isn’t really that complex, but sadly, it is a bit too complex to be well managed by the press and others talking about it, in many cases.

And, the distinction is huge. Conflating the very small number of possible infections “across the room” (which are speculative but possible) in prior outbreaks (which, Jane, were not in East Africa) with an airborne mode of transmission is like working out transportation policy for the US but mixing up the part about how cars don’t fly and airplanes do. I really think Ebola is not going to become airborne. But if it was airborne, the whole ballgame would be very very different. That, however, does not mean that Ebola is not a very serious thing that needs to be addressed. Also, the utter failure to address this by the systems in place tells us that we as a society/species/collection of governments are unable to address a serious public health crisis even if we were under the impression that we were. Trading in misinformation and badly conceived ideas of what is happening or what could happen sets us back, it does not move us forward.

More on Ebola:


*Actually, this may not be true, to my knowledge no one has considered this, certainly not tried it!

UN Security Council Resolution on Ebola

Just a quick note. The UN Security Council has ad its first ever emergency meeting over a health issue, specifically the current West African Ebola outbreak. From a summary in Science, the Council …

… unanimously passed a resolution that declared the spread of the virus a “threat to international peace and security” and called on the world to send more health care workers and supplies to Liberia, Sierra Leone, and Guinea, and not to isolate those countries.

U.S. Ambassador to the United Nations Samantha Power, who chaired today’s meeting, noted that the resolution had 130 co-sponsors, more than any previous one in the history of the Security Council.

Has #Ebola Death Toll Surpassed Malaria in West Africa?

In the earlier days of the West African Ebola outbreak, it was not uncommon to hear people note that we should not panic about Ebola because, after all, far more people are killed from Malaria than Ebola. This is of course an irrelevant argument. That is like telling a person who has lost their family in a tragic airplane accident that it isn’t so bad because, after all, far more people die in car crashes than aircraft crashes. For example, on August 5th, James Bell write in the Guardian, in a piece called Concerned about Ebola? You’re worrying about the wrong disease:

Since the Ebola outbreak began in February, around 300,000 people have died from malaria, while tuberculosis has likely claimed over 600,000 lives. Ebola might have our attention, but it’s not even close to being the biggest problem in Africa right now. Even Lassa fever, which shares many of the terrifying symptoms of Ebola (including bleeding from the eyelids), kills many more than Ebola – and frequently finds its way to the US.

I’m not picking on James Bell here. A lot of people said things like this, and the facts are true, though as I said, there is almost always (actually, in exactly N-1 scenarios within a given domain of scenarios) an argument that goes like this, and it really isn’t particularly relevant unless one is tasked with dividing up a fixed set of resources that will be used for a fixed set of problems. Resources rarely come that way and problems are rarely solved that way. As I pointed out earlier, consider the thought experiment where you have $10,000,000 that you want to give to either developing an Ebola vaccine, or a Malaria vaccine. Since billions have been spent on developing a Malaria vaccine and there still isn’t one, your donation would be a drop in the bucket. Retrospectively, it would be equivalent to something like the combined costs of couriers and mail by researchers working on a Malaria vaccine over the last few decades. Or the cost of coffee and donuts in the break room. Or conference travel fees. Or something like that. The point is, a bunch of millions of dollars might actually produce an Ebola vaccine given the starting point we have now, or at least, move us a good deal in that direction.

But now, we can ask if Ebola in the countries that are heavily affected right now is still “minor” compared to Malaria.

This is a matter of numbers and the numbers are hard to come by. James Bell notes that between February and July, inclusively, there had been over 300,000 malaria deaths, I assume world wide. So the comparison is not really relevant; we should be looking at what is happening specifically in, for instance, Liberia, Guinea, and Sierra Leone (or the three combined perhaps). Comparing world wide figures to a regional outbreak is a bit like reducing the Malaria death rate by shifting from numbers from countries that have endemic Malaria to include the global population.

It is hard to know how many people die of malaria every year, and the quality of the data varies considerably from country to country. A fairly recent study (here’s a discussion of it) suggests that an older estimate of 600,000 deaths per year should be doubles to 1,200,000 deaths per years. Having worked and lived in a region with some of the worst malaria (measured numerous ways) for several years, I can easily accept a doubling of numbers. If we assume that 1.2 million is right, by the way, Bell’s number of 300,000 is actually conservative.

Using data from that malaria study and WHO’s Ebola data, we can make some comparisons. I’m including all the information so you can check my work.

Here we have data from Liberia, Guinea, and Sierra Leone. The population number and malaria deaths per year are both from the aforementioned study and pertain to 2012. Then I divided malaria deaths per year by 12 to get a monthly value. I’m more comfortable working in months than years because an Ebola outbreak is normally short lived, and the number of deaths changes dramatically from month to month.

Following this we have the total number of Ebola deaths per country (summed in the right hand column as are the above mentioned data) and the approximate number of months of the outbreak. Then, the total deaths divided by the number of months. This constitutes a low-ball estimate of deaths per month from Ebola for the given expanding outbreak. Here we can see that in the comparison between Malaria and Ebola, it is not clear that one is a greater threat than the other (142:92, 49:67, 145:144).

Then we have the August-only monthly number of deaths. Here we dee that Ebola is huge compared to Malaria. So, back when people were saying “Malaria is worse,” in late July and early August, Ebola was starting to prove them wrong.

The last two numbers are calculated for all three countries combined. Here we are going out on a limb, and it is better statistically to crawl out on a thicker limb than a thinner limb. I made some estimates here, and those numbers conform to what is being talked about by WHO and others. If Ebola continues to spread at its current rate the daily number of new cases could be between 150 and 300 by the beginning of January. I state these as low vs high estimates, but actually, they are both conservative. Multiplying this by 30 days in a month, and dividing by 2 to approximate the ca 50% mortality rate, we have conservative numbers for Ebola that leave Malaria in the dust. Even if the doubling of estimated Malaria death rates should be doubled again, Ebola will be a bigger factor than Malaria.

Liberia Guinea Sierra Leone Total
Population 3,954,977 10,068,721 5,696,471 19,720,169
Malaria Deaths Per Year 1706 586 1734 4,026
Malaria Deaths Per Month 142 49 145 336
Ebola Deaths Total 508 400 461 1,369
Months of outbreak 6 6 3
Monthly average Ebola deaths 92 67 144 303
August Ebola Deaths 644 148 224 1,016
Estimated Janurary Ebola Deaths (low) 4,500
Estimated Janurary Ebola Deaths (high) 9,000

So that is why we should stop saying that Ebola is not Malaria, so relax about Ebola.

More on Ebola:

Update on West Africa's #Ebola Outbreak: Getting worse

The news is bleak. I don’t have a lot of confidence in the reported numbers. At one time it was said that on a nice Saturday in the summer, four out of five cars driving around in downtown Boston were looking for a parking place. This is somewhat like the situation in Liberia and possibly other affected areas. There may be as many Ebola victims driving around in taxis looking for a clinic as there are in clinics. Or maybe a fewer. Or, maybe more. Maybe a lot more.

But, we have to work with the data we have. There are two charts based on the information provided by WHO for up through September 6th. I’ve projected each data set out 90 days. Since there is no abatement in frequency of new cases, and in fact the number continues to increase on average, and since WHO is claiming that the situation in the worst hit areas is pretty much out of control, a 90 day projection seems reasonable. In other words, there is no reason to think that the relative rate of new infections is going to change because of any outside intervention or internal change in the situation.

The first chart shows the number of new cases. This varies a great deal from report to report. Some of that variation over time is probably real, reflecting the internal complexities of disease spread. But I suspect it is mostly administrative. If a bunch of cases don’t get into one report, the get into the next report. This explains a nearly perfect alternation between increase and decrease between successive reports.

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The second chart shows the number of cases over time, accumulated. This Projected outwards, we can guess that by around the beginning of 2015, there will have been over 10,000 people who have been infected by Ebola in West Africa (including Nigeria and Senegal as well as the main area of the outbreak), and over 5,000 deaths. Since I know you are curious, if this is projected out over a year or so, the number of infected people goes to between 60,000 and 70,000. I have no idea if this is realistic.

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The situation is bad and getting worse.

#Ebola in West Africa: Update

WHO has put out very few updates in the last several days. The most current update is August 28th, and it pertains to information from August 26th and before. Based on that update, the total number of cases (confirmed, suspected, etc.) is ow 3069 with 1552 deaths. The number of new cases per day may be increasing, may be decreasing; hard to say at this point. Here’s the new cases per day since the second week of July:

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Senegal now has one case, a person who traveled there from Guinea. He had contact with a lot of people including health workers and family before it was figured he may have Ebola. There is no word from the Congo since I last wrote about it, at least from WHO.

I’m sure Murphy’s Law will apply and WHO will issue new information soon after this post goes up, so expect an update very soon.