Our cities and pandemics go hand in hand, influencing each other in a subtle tug-and-pull, oftentimes with important and long-lasting consequences.

Diseases shape urban design

In the mid 19th century, John Snow was somewhat of an outlier in the scientific community. He wasn’t a believer in the then-dominant miasma theory which assumed that diseases such as cholera and the plague were caused by pollution or a noxious form of “bad air”. Instead, Snow believed something else was at work, so in 1854 when the cholera outbreak ravaged London, he did something no one else had thought of before: he made a map of the infection.

“[N]early all the deaths had taken place within a short distance of the Broad Street pump,” Snow wrote, identifying that water pump as the source of the cholera outbreak. With it, he discovered a pattern suggestive of a different spreading mechanism.

His theory was indeed correct. As we all know today, cholera spreads through infected water, not miasma. It took some time before Snow finally persuaded the local council to disable the public well pumps by removing their handles. It took a bit of political back-and-forth, but ultimately, Snow’s theory changed the way cities use public water pumps forever. This is just one striking example of how diseases can shape our cities, and it’s far from being an isolated one.

Urban design and public health intersect in many ways. It’s not always an exact science, as many external factors come into play in this equation (things such as culture and physical geography), but the way we design our cities does affect outbreaks.

Large cities (over 1-2 million people) tend to gain accentuated value in many societal aspects. They tend to have a better-educated population, more jobs, more entrepreneurs, and so on. But they also bring higher risks when it comes to things like violence, pollution, and epidemics. The same underlying mechanism that boosts urban innovation can also explain why certain types of crimes (and outbreaks) thrive in a larger population.

The downsides of large cities are often overlooked in comparison to the advantages they bring, but COVID-19 is forcing us to re-think how we design our cities — especially as global epidemics are becoming become more frequent. Increasingly, epidemics are becoming global — and urban — problems. This makes disease an aspect worth considering both for sprawling metropolises and up-and-coming urban areas.

More than just urbanization and densification

It’s easy to look at COVID-19 and say it was amplificated by globalization. But this doesn’t tell the whole story.

Outbreaks like this one start in and spread from the edges of cities, and into urban and suburban areas. Rapid urbanization enables the spread of infectious disease, and peripheral sites are particularly susceptible to disease vectors like mosquitoes or ticks. Increasingly, cities aren’t uniform, singular bodies — they are more like amorphous blobs, split into clusters connected in ways that are often complex. People’s income, age, habits, and culture can play a role, as do existing infrastructure and geography

They are all linked, however, by transportation. A city’s transportation is its lifeblood — and also the first route of possible disease spread. COVID-19 spread far and wide through airports, and most airports were not designed to feature quarantine areas or medical testing. This is perhaps the simplest and most consequential urban change that can be done to limit the risk of a disease spreading into the city, yet it’s often overlooked.

There is a healthy amount of chance involved in how diseases spread as well. New York is one of the most globalized cities in the world, but its outbreak happened weeks after the one in Italy and Spain, and studies have suggested that most of NYC’s coronavirus cases came from Europe itself.

Regardless of how it happens, once a disease starts to spread inside a city, things get much more complicated and site-specific.

Cities urbanize the areas around them in different ways. In the US, suburban areas are often hubs for affluent people whereas, in most of Europe, central areas are more desirable. This can influence disease spread, and it’s important to look at cities in their cultural and historic context.

Density alone also doesn’t tell the whole story.

Hong Kong has 17,311 people per square mile, and yet it managed to contain its outbreak admirably so far. It’s also a very cosmopolitan city, very close to China — a prime suspect for a severe outbreak, but Hong Kong hasn’t even come close to what New York is seeing.

Meanwhile, Washington state (much like what we have seen in Italy) is largely suburban, yet the disease has still spread with stunning speed. It’s still early to draw any crystal-clear lessons, but the level of urbanization doesn’t necessarily seem to correlate with how heavily hit an area is. There are likely other, more subtle aspects at play, which city planners will need to analyze and adapt to, just like they did after John Snow’s findings.

Rich-poor segregation also doesn’t really help cluster down the outbreak. In several US communities, the disease was brought in by inhabitants of affluent suburbs, but then disproportionately spread to some of the poorest neighborhoods. Quite likely, some affluent areas are spared because their inhabitants can afford to enter quarantine or work from home, whereas this might not be the case in other neighborhoods.

Digital infrastructure

Imagine if this pandemic would have happened 10 years ago. The mere thought that we would have to do this without internet deliveries is horrifying. Then, there’s all the digitized information that both we as citizens and decision-makers have available at our fingertips. There’s never a good time for a pandemic, but at least in terms of digital infrastructure, we’re way better prepared than we were a few years ago.

Digital infrastructure is becoming an increasingly important part of a city’s infrastructure, but we need to find ways to use it properly.

The next challenge is to figure out what data is useful, how to get it, and how to make decisions off of it. A good example in the current pandemic is Johns Hopkins’s CSSE aggregator of information. This dataset and visualization, which we have also used, was extremely useful in understanding the scale and overall evolution of the disease at the global level. As the outbreak progressed, several other datasets emerged, on international, national, and even local levels.

Having access to this unprecedented level of data is a game-changer. Even for cities lacking a solid digital infrastructure, having access to open-source data enables decision-makers to plan with unprecedented quality of information. Meanwhile, countries that have invested in building this digital infrastructure up are reaping the rewards. In Germany, for instance, you can watch a real-time map of hospital bed capacity, showing which areas are at full capacity and which can still take extra patients — an initiative which can be carried out at low costs, but which can carry huge rewards.

Much like they organize streets and buildings, city planners will need to look at what digital infrastructure is required in a city, and how it can be organized and used both in normal times and in times of crisis. The amorphous shape of cities will also carry on to the online infrastructure.

Looking into the next few years, as the world will start to shake off the COVID-19 crisis, we will enter another wave of megaurbanization. Urban regions would do well to develop efficient and innovative methods of confronting emerging infectious disease without relying on drastic top-down state measures that can be disruptive and often counter-productive.

Over the course of this pandemic, the US has demonstrated just how important it is for cities to be able to fend for themselves, and how devastating it is when they don’t.

In general, urbanization plans should account for fighting racism and intercultural conflict. Epidemic planning also falls into this category, and it’s more important than ever for cities to also consider this.

Cities are hotspots of innovation and solution-finding, but they can also be hotspots of disease spread. From cities, we will find both our solutions and our biggest problems. COVID-19 isn’t the last global outbreak we will have to face. Hopefully, the world’s cities will rise up to the challenge.