This is partly why there have been rival Ebola-like 'haemorrhagic plague' theories of the Black Death, although they're still niche theories.

Confusing matters is the fact that some accounts of symptoms make it sound like Pneumonic plague was also affecting victims, and killing them even faster. Possibly there was some perfect storm of plagues spreading through multiple vectors at once, with haemorrhagic pneumonic and bubonic plagues striking at different places with different frequencies.

Without a means to distinguish between the plagues (and other diseases), pretty much any death caused by communicable disease would at the time be considered part of the Black Death.

Doesn't that make Ebola more deadly? 21 days walking around, spreading it.

My understanding is that Ebola is not very contagious. You need physical contact for the disease to spread. Which is why there was some many victims among nurses and doctors. But also why it is unlikely you will be contaminated if you sit 5 hours in a plane next to someone carrying the disease.

And the interesting thing about Ebola is that while it's not very contagious it is extremely infectious. Which means that you need contact with just a few virus particles to be infected.

It turns out its not actually all that infectious either. It's just very, very hard to sustain not having contact with infectious fluid for very long.

And then it's game over, low survival rate. Which makes it scary but not very dangerous.

I would bet the deadliness of Ebola has been overstated (at least by a little, probably by a lot). Like any infection, many people who get it are probably asymptomatic, and until recently the vast majority of people tested for it were most definitely symptomatic. http://www.theguardian.com/world/2015/oct/15/ebola-study-fin...

Transmission of Ebola occurs only after patient develops the symptoms of the disease anywhere between 2 days and 3 weeks after infection [1]. By then most patients are not in a condition to be "walking around".

[1] https://en.wikipedia.org/wiki/Ebola_virus_disease

Ok. I was later thinking that this might be the case. Thank you for finding it.

That's another way of thinking. But a deadly disease is one where death is certain and fatality rate is high. You could say that Ebola had higher chances of spreading, along with being deadly.

Ebola can be quite fast. 4 to 10 days incubation period and then death may occur in the next 6 to 16.

https://en.wikipedia.org/wiki/Ebola_virus_disease

Diseases which kill immediately upon contact don't tend to spread. It's the ones that sit silently and don't harm you that spread everywhere (e.g. HIV)