Just six weeks ago the risk from the Ebola outbreak was not looking too bad as these things go.
People in the U.S. were somewhat panicked by the knowledge that Ebola patients were being brought into the U.S. for treatment and suspected cases were popping up in other hospitals, all of which turned out to be false alarms.
Even he patients were treated and cured and the death rate appeared to be lower than expected in Africa, so the situation was looking positive.
But recently the news has all been bad and the threat is looking a lot more serious, although the risk of an actual pandemic is still considered low.
On September 8 a report published by the AAAS (American Association for the Advancement of Science) in “Science” looked at the supposed lower fatality rate of the infection.
This is important because one reason it was thought the danger wasn’t as bad because of the lower death rate or CFR (case fatality rate).
The initial reports published by the WHO (World Health Organization) stated that the infection rate (the number of people infected) was growing rapidly but the overall fatality rate is 53%, as low as only 39% in Guinea.
That would be terrifically good news, showing a new strain of Ebola might be less lethal. Unfortunately the good news was all due to statistical errors.
When the infection rate is expanding really fast that means that the survival rate is artificially inflated to the good side simply because the survival rate is the number of deaths divided by the number of infected cases.
Simply put, it takes a while for people to die and when there are a lot of new cases there are still a lot of people alive.
Ebola Cure?
Another piece of potentially good news is that the two people brought to Atlanta for treatment were both cured.
Unfortunately the cure of two individuals used up the ENTIRE world supply of the most promising Ebola medicine, AND that may not actually have been the cure, supportive efforts may have contributed as much to their survival by giving their bodies enough time to fight the infection.
Ebola is a hemorrhagic fever with symptoms similar to that of extreme radiation exposure. hemorrhagic refers to blood and a hemorrhagic disease essentially breaks down the blood vessels and blood leaks into the body.
Since Ebola is a virus there is no good treatment for it and the patient must defeat it with their own immune system.
To keep them alive long enough for this to happen you must give them oxygen and a lot of intravenous fluids.
That isn’t easy even in a developed country but in rural Africa is is virtually impossible which explains why 100% of the patients in the U.S. survived and only 10% of those treated in Africa survive.
Pandemic Threat?
Practically speaking, there are two core requirements for a dangerous pandemic.
First, the disease must be easily passed from one human to another.
Second, it must be very deadly.
The WWI (~1919) swine flu was both, killing about one hundred million people back when very few people were flying around, spreading disease.
The yearly flu is killing tens of thousands of people but because of the large number of people infected, it isn’t classed as a pandemic due to the relatively low CFR.
The yearly bird flu virus threats are also easily transmitted ONCE they mutate in a human host. This either has not yet occurred or has always been contained, but the various bird flu varieties do pose a pandemic threat.
That brings us to Ebola.
The second criteria has obviously been met. All indications are that this outbreak is as deadly as previous ones, meaning a 90% fatality rate.
But, what of the first? How easy is it to catch Ebola?
Initially HIV/AIDS was thought to be extremely contagious and people would avoid even being in a room with an infected person.
That was the early days of near total medical ignorance.
Now we know it will pass only via bodily fluids and, is, in fact mainly an STD which means, barring accident, you can only catch it by close, sustained contact – even sharing needles is a case of sharing bodily fluids.
HIV is actually a very good comparison because Ebola infections are also caused by direct contact with bodily fluid – to qualify as a pandemic threat a disease must be airborne.
Being on the same airplane with an Ebola patient is not particularly dangerous.
Ebola Bottom line?
The bottom line is that if you catch Ebola you are in big trouble, but it is extremely unlikely to spread much beyond countries with third-world sanitation and medical practices.
