Assistant Professor Anne Austin specializes in the history of health and disease and has combined the fields of osteology and Egyptology to document medicine and disease in the past. (Photo by August Jennewein)

Since its onset, the COVID-19 pandemic has resulted in nearly 6 million deaths worldwide and more than 950,000 deaths in the United States alone. It has disrupted daily life to varying degrees over the past two years, and it is the first disease event since the 1918 influenza pandemic to warrant an urgent global response.

Outbreaks of infectious diseases such as COVID-19 have been a constant throughout human history. Aside the from the loss of life they inflict, epidemics and pandemics have also significantly altered the societies through which they spread. Historically, these events have shaped economics, medicine, politics and public health, with their effects rippling for years or, in some cases, decades.

Anne Austin, an assistant professor of history at the University of Missouri–St. Louis, specializes in the history of health and disease and has combined the fields of osteology and Egyptology to document medicine and disease in the past.

In the latest installment of its Ask an Expert Series, UMSL Daily spoke with Austin to examine the historical impact of epidemics and pandemics on society and what it tells us about the present realities of COVID-19.

In the past, how have pandemics changed society?

There are several pandemics that we have been able to really cleanly identify in the past. One of the causes of pandemics in the past is Yersinia pestis, which is this bacterium that causes the plague, or the Black Plague. When we look at some of the plagues from the past and we find those plague victims, scholars have done DNA analysis and identified that it’s Yersinia pestis that you find in some of those burials. That’s one way that people have been able to identify a very specific cause of death. That caused the Plague of Justinian. It also caused the Black Death in Europe. Bubonic plague is still around today, actually. You can still get it in America today. It’s just much less common.

When we look at the big impacts of something like the plague, it really affected public health. We see, for instance, the introduction of isolation and quarantining and the effects of that. People didn’t fully understand germ theory, but they recognized that things were being spread by people who were near each other. You see the introduction of hospitals during that time. If we think about what medicine looks like today, a lot of it is actually influenced by these pandemics.

We can look at something like cholera, which St. Louis has a really local history with. We had multiple cholera outbreaks in St. Louis in the 19th century. The biggest one was in 1849, and that was a huge cholera outbreak. It’s hard to understand the quantity of it. Around one in 10 St. Louisans died during that outbreak. In the worst week, in July of 1849, over 700 people died of cholera. If we think about that in reference to COVID, so far, COVID killed around 3,000 people in St. Louis County. That’s a huge number, and in 2020, it was the third-leading cause of death. But that really pales in comparison. It was only about 0.3% of the population. That’s not to make light of COVID, but just to show how intense this cholera outbreak was.

If we look at cholera as a pandemic, it’s really interesting to think about what changes we see in St. Louis during that time. The way we got out of cholera was a doctor from London started to notice a correlation between people who were getting sick and the water that they were accessing. He hypothesized that it was the dirty water that was spreading cholera. So, he did some experiments to see if that was the case. In 1849, he published on this. This was the same time that we were seeing this big problem in St. Louis, and they started to clean the water supply. It was only then that they started to see the numbers come down and St. Louis started to get out of this really deadly pandemic. It was a major change. All of our water infrastructure and public health infrastructure around hygiene, personal hygiene and sanitation grew out of this big need to deal with cholera.

You mentioned the impact of public health. What about personal health habits? Historically, how have those changed?

In terms of personal health, understanding germ theory really shifts. What’s interesting is when I look in ancient Egypt and at the way they describe how people get sick, they describe something that’s not actually that far off from germ theory. They talk about the idea that something can get inside your body, that you need to remove it from your body. They were really careful about their sanitation because they were worried about this idea of getting infected. But where the infections came from, the way that they pictured them is really different from how we picture viruses and bacteria.

When we look at the more recent 19th century, people were really worried about air and polluted air. They were really careful about the air that they were breathing. We see these same issues coming up today when thinking about how COVID is being spread. Even though there’s totally different theories there, miasma theory – the idea that things are being spread through polluted air – is different than the way we talk about germ theory. But the end result is the same, right? Your personal habits around the air that you breathe becomes really, really different.

It’s interesting to think about how culture understands disease and how that influences personal hygiene. Sometimes it takes one of these pandemics to really shift the way that we as a culture understand disease. Now, we’ve done so much new research on how viruses are spread that, even during the pandemic, we’ve changed our idea around how our air contaminates. From these ideas of droplets to that COVID can be aerosolized. We’ve already seen some of the shifts at a public level and at a private level just in the past few years.

Are there any other parallels between past pandemics and today?

Looking at the cholera outbreak here in St. Louis, I see tons of parallels. When it starts, we don’t know exactly how cholera is spread and people are afraid. Like I said, huge numbers of people are dying.

One of the things that starts really early on is blaming foreigners and saying that the German immigrants that are coming to the city are the ones that are bringing and spreading cholera. You see that play out in news reports. You see it play out in the way that the local public health committee deals with it. They make beer illegal because that’s something that’s part of the German immigrant experience. The xenophobia that we saw at the beginning of COVID-19, with people really attacking Chinese immigrants and Chinese Americans and Asian Americans more broadly, I think definitely connects to the way that German immigrants were treated here in St. Louis in 1849.

You also see that people use their wealth to protect themselves during these periods. One way that people protect themselves is moving out of the city and starting to really build up the county or areas that are a little bit more rural. Only the people who can afford it are able to do that. That happens in St. Louis. People see that people who get cholera are getting it in these densely populated parts of St. Louis city. So, they move out toward the county, which starts building out the county. It leaves all these businesses in the city pretty high and dry. If you look at the areas where real estate’s really picked up during the pandemic, it’s been a huge shift in the value of homes in these slightly more rural areas. It’s a really big difference in impacting who is able to escape a disease and who is really subject to it.

Right now, there’s a lot of talk about COVID-19 becoming endemic. What does it mean when a virus or disease becomes endemic?

It’s something we expect to stay around with relatively predictable infection rates. If you look at influenza, that’s endemic. What we expect every year is a certain number of people are going to get infected, that those infections are going to be higher in our winter months and they’re going to go down in the summer months.

If COVID-19 becomes endemic, what would that look like for us? Well, already, it’s probably here to stay just based on how many people have gotten it and how transmissible it is. If you look at how a lot of people who are in public health view it in that sense, it’s already here. What’s not quite happened yet is it hasn’t reached these predictable levels, where we expect to see waves during certain times and not others. I think we’re going to need to wait and see how that evolves.

As more people get vaccinated and/or get sick, we’re hopefully not going to have these huge waves of people getting hospitalized at the same time. It will start getting into a much more predictable pattern that we can then make sure health care is structured to support.

Can an endemic virus still be dangerous?

When we talk about how dangerous a virus is, we often talk about how dangerous it is to the whole population. An important thing to keep in mind is that it’s way more dangerous to certain people than other people. When we talk about death rates for disease, we say, ‘Oh, but only this small percentage of people who get it are dying.’ Well, let’s put that in perspective and think about who those people are and what does it mean for them when a very large percentage of a select group of people are dying?

Influenza still kills lots of people, and we take it very lightly. But if there are actions that we can take that can prevent people from dying from influenza and they are actions that are pretty easy to take, I say we should do it because it’s still a deadly and dangerous disease to a small percentage of our population.

What does history tell us about how a deadly virus can over time become a more manageable threat?

One horrifying thing is that, in some cases, deadly viruses and bacteria in the past have only become more manageable by killing off huge numbers of people. If we look, for example, at the Black Death, it only lasted around five years. But in certain areas of Europe, like densely populated London, it killed half of the population. It’s crazy to think about that.

I mean, in “Avengers: Endgame,” Thanos, who’s the world’s greatest super villain, snaps his finger and kills half the population. And that scene is the most villainous thing that could happen. It’s not fiction. It’s real, right? That’s history. We saw that happen with the Black Death. But it wasn’t arbitrarily choosing people. It was choosing people who had less access to wealth, people who had less ideal living conditions, people who were younger, people who were older, people who were immunocompromised. What ended up happening was that it selected out so many people that were more vulnerable, that the people that were left were a relatively healthier population. That was only after selecting half the people and killing them. That’s hopefully not the direction we are going to go.

Another example would be smallpox. When it was first introduced in the Americas, it likely killed even more than half of the population. It was a huge issue in Europe for a very long time. The only way that smallpox stopped being such a big issue was when a doctor found out about a woman who had a different disease that seemed very similar to smallpox. It was called cowpox, but she wasn’t dying from it. In that case, he used that version of the virus to make a vaccine, and it turned out that made a much safer way for people to get sick without dying. He used the smallpox vaccine to start treating people, and years later, smallpox was totally eradicated. That’s a good example of a way that we got out of a very dangerous virus through vaccination.

Another way viruses can become less deadly over time is just through natural selection. We often use the phrases “natural selection” and “survival of the fittest” to think of something that’s big and strong. For a virus, you might think of the deadliest version of a virus, but in reality, natural selection is just about what can reproduce the most effectively. A virus that’s less deadly but more easily transmitted is going to spread through a population. It’s going to be reproduced way more effectively than one that kills its host before they have a chance to spread it. We’ve seen, possibly, this shift already happening with omicron, where we have a variant of COVID-19 that appears to be less deadly and more easily spread.

That being said, even our population has changed dramatically in the last year because of our vaccination efforts. I think that it’s a possibility that this could be a direction that COVID could go, but we’re still waiting to see what happens next. Hopefully, we get in that direction through both vaccination efforts and less deadly variants of the virus, where we shift toward something that’s much more sustainable, much more preventable and much more easily combated than the version of COVID that we started with.