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How many people died of the plague? (draft)

One of the first queries that comes up when you google "how many people died of", is how many people died of the (black) plague. Unfortunately, pretty much every answer that you can find online is wrong.

Google Suggest top hits - how many people died of
300 years after plague died out in Europe, it is still heavily present in people's mind

You will get plenty of answers when you search for the death toll of plague - there are answers on Wikipedia and on Encyclopedia Britannica. There are nice visualizations made by the National Geographic and the Visual Capitalist, and many books or scientific publication on plague will list a death toll somewhere in their introduction.


But they are all wrong, in one of these two ways:

  1. Most websites are just parroting each other's random numbers (BBC, Reuters, etc), and then get cited by Wikipedia as a credible source.
  2. The most commonly returned answer by search engines is specific to the 1346-1351 Black Death epidemic in Europe. That is not the question that we asked!

So, let's see how far we can get in answering how many people died of the plague.

The Time before the Three Plague PandemicsπŸ”—

The first thing you need to know is that plague has been killing people for at least 5,000 years1. And when you move that far back in history it becomes extremely difficult to assess how many people lived, let alone how many people died of a particular disease. However, it does look like that 5,000 years ago plague was already wrecking havock: remnants of the plague bacterium have been found across Eurasia2, in a surprising large fraction (like 2.5%) of the corpses that were tested for the presence of ancient plague DNA.

A map of ancient plague findings, predating the known pandemics
Plague has been recovered from human remains for at least 5,000 years (compiled from literature)

The First Plague PandemicπŸ”—

Fast forward 3,500 year, and we arrive in Pelusium, Egypt in 541 AD. The outbreak recorded in the historic records in Pelusium is typically considered the start of the First Plague Pandemic, which lasted until 750 AD. The plague spread across Europe, and DNA of the plague bacterium has been recovered from dozens of sites, confirming that this was indeed a plague pandemic3,4. The plague may have well spread into Africa and the Middle East as well - we just have very little information about what happened outside of Europe.

There is a very lively scientific discussion ongoing on how deadly this first plague pandemic actually was5,6, and it is worth reading both sides to get a feeling for the challenges of tallying up the dead in historic times.

In between the First Two PandemicsπŸ”—

If you somehow succeeded in tackling the challenges of enumerating the dead from prehistoric plague outbreaks and from the First Plague Pandemic, be mindful that you do not skip over the period between the end of the First Pandemic in 750 AD and the traditional start of the Second Pandemic in 1346 AD7.

It has been something of an entrenched idea that the Black Death was the start of the Second Plague Pandemic, which means that outbreaks between 750 AD and 1346 AD were not considered in the context of possibly being plague. That idea is changing now with a recent publication on plague in Baghdad, Iraq in 1258 AD8, and it wouldn't do to forget those places in an accurate tally of the total death toll of the plague.

The Second Plague PandemicπŸ”—

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In between the Second and Third PandemicsπŸ”—

It has also become embarrasingly clear the outbreaks that were typically considered the end of the Second Pandemic (the plague of Marseille in 1720-1722 or the plague in Moscow in 1770-1772), were only so from a rather narrow western-Europe perspective.

When you take older compendiums of plague, such as that of Georg Sticker 9, you will find records of (presumably) plague present from Eastern Europe to India between 1723 to 1893. With the Third plague pandemic starting in 1788 or 1855 in Southwest China, depending on who you ask, there is not much time or space left between the end of the Second and the start of the Third pandemic.

Plague in Central Asia in between the Second and Third Plague Pandemic
Plague in Central Asia in between the Second and Third Plague Pandemic

After the Third Pandemic.πŸ”—

There is not really a well-defined end of the Third Pandemic, but looking at various papers from different continents (Bramanti, Kuguler, Sun, Neerincxk, Jones), plague stopped being an epidemic disease around the 1950's, with case numbers returning globally to close to 0. Plague kept flaring up in outbreaks spilling over from local wildlife reservoirs after the '50s, but there is nothing that signals that plague was still spreading across large areas.

There is still plague around, but with about 100 deaths per year, the disease is virtually eradicated.

What numbers DO we have?πŸ”—

We can work backwards, and try to tally up the number of deaths, or the estimates thereof. Plague data used to be reported in tabular form at the WHO, but those databases appear to be no longer public, so we reconstruct what we can. Mostly, we depend on publications and public health institutes, and we work per continent. Note that I am taking the numbers mostly at face value, and am not trying to estimate over- or under-reporting. That is another can of worms!

The AmericasπŸ”—

Plague was introduced into the United States around 1900. For the number of deaths, we can use Kugeler's work for the time period 1900-2012, augmented with the latest years from the CDC. Between 1900 and 2019, there were 1047 probable or confirmed plague cases. 416 of these cases died. If we assume that the 17 cases for which no disease outcome are from the pre-antibiotic era, then about 2/3rds of them would have died, bringing the total tally of all plague deaths ever in the United States up to just 427 deaths.

One caveat is that we don't know if plague was ever introduced to the Americas prior to the Third Pandemic, but just failed to establish itself permanently. The current plague reservoirs in the Americas all appear to be genetically derived from the Third Pandemic plague strains that spread around the world, but that does not rule out earlier introductions. For the time being, we set the death toll of plague in the Americas prior to 1899 to 0.

Australia and the PacificπŸ”—

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AfricaπŸ”—

(insert Neerincxk, Green and Chouin)

EuropeπŸ”—

(insert)

AsiaπŸ”—

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FootnotesπŸ”—

1

Andrades ValtueΓ±a et al. (2017) β€˜The Stone Age Plague and Its Persistence in Eurasia’, Current biology: CB, 27(23), pp. 3683–3691.e8.

2

Rasmussen, S. et al. (2015) β€˜Early Divergent Strains of Yersinia pestis in Eurasia 5,000 Years Ago’, Cell, 163(3), pp. 571–582.

3

Wagner, D.M. et al. (2014) β€˜Yersinia pestis and the Plague of Justinian 541–543 AD: a genomic analysis’, The Lancet infectious diseases, 14(4), pp. 319–326.

4

Keller, M. et al. (2019) β€˜Ancient Yersinia pestis genomes from across Western Europe reveal early diversification during the First Pandemic (541-750)’, Proceedings of the National Academy of Sciences of the United States of America, 116(25), pp. 12363–12372.

5

Mordechai, L. et al. (2019) β€˜The Justinianic Plague: An inconsequential pandemic?’, Proceedings of the National Academy of Sciences of the United States of America, 116(51), pp. 25546–25554.

6

Sarris, P. (2022) β€˜New Approaches to the β€œPlague of Justinian’, Past & present, 254(1), pp. 315–346.

7

Barker, H. (2021) β€˜Laying the Corpses to Rest: Grain, Embargoes, and Yersinia pestis in the Black Sea, 1346–48’, Speculum, 96(1), pp. 97–126.

8

Fancy, N. and Green, M.H. (2021) β€˜Plague and the Fall of Baghdad (1258)’, Medical history, 65(2), pp. 157–177.

10

Krauer, F. and Schmid, B.V. (2021) β€˜Mapping the plague through natural language processing’, medRxiv Preprint.