A brief history of bubbling: Why quarantine habits are much older than you might think

Over the past six months, we've been slowly adapting to a new way of living. We have to remember to pocket our masks before we leave the house, we have to keep our eyes peeled for one-way arrows in grocery store aisles, and, most of all, we have to be mindful of who's in our bubble and to keep a safe distance from everyone else.

Bubbles, cohorts, social circles there are different names across the country for the small groups of friends and family we choose to have close contact with while the pandemic is in effect.

The idea of isolating apparently healthy people from each other during a pandemic, which is what we're doing when we stick to our bubbles, is a relatively new approach to public health.

To understand how we arrived at the social distancing strategy we're using to cope with COVID, you have to look back at the long human history of disease management.

Although germ theory has been widely accepted for only about 150 years, human beings havehad a basic understanding of contagion for millennia. For most of that time, people tried to contain infectious illnesses by sequestering the sick.

The Book of Leviticus in the Hebrew Bible recommends isolating people who are infected with certain diseases, like leprosy, from the rest of the population; it also suggests washing or burning their clothing.

In the Middle Ages, European towns and villages tried to protect their citizens from plague by barring entry to people from infected communities. Some areas set up highway roadblocks with armed guards; towns with walls literally closed their gates to outsiders.

Venice was the first place to institute a preventive quarantine program. It was during the Black Death of the 14thcentury, a pandemic so severe it killed at least a third of Europe's population.

Venice was a major international trading centre, and ships from other parts of the world were constantly arriving there to drop off or pick up merchandise. In 1348, the Venetian Republic instituted a policy that required ships from infected ports to sit at anchor for 40days before landing. This practice was dubbed quarantine, from the Italian quaranta giorni, meaning "40 days."

40 is a powerful number

Why 40 days? The number could have been inspired by ancient Greek medicine. In the Hippocratic school, 40days was considered a turning point for disease: it was thought that acute, infectious illnesses would manifest within 40days and any disease that remained after that period must be chronic and not contagious.

For the Christian authorities of Venice, 40days would also have had religious significance. Moses spent three periods of 40days on Mount Sinai, the Israelites wandered 40years in the wilderness, and Jesus fasted 40days in the desert. In these biblical examples, the number 40is associated with a trial or test period another reason 40days may have seemed like an appropriate amount of time to wait out an illness.

Listen: Apocalypse Then, with Ainsley and Andrew Hawthorn:

About a century later, the Venetians came up with another innovation in infectious disease control: the lazaretto. Lazarettos were quarantine stations where individuals believed to be ill were sent to live until the sickness had passed. These hospitals, residences, or compounds were segregated from the rest of society. They were often quite literally islands unto themselves.

Isolating the sick has been a common way to manage disease outbreaks ever since. St. John's had a series of "fever hospitals" separate from the general hospital, including one on a remote outcropping of Signal Hill.

These facilities received residents with smallpox and other contagious illnesses to prevent them from infecting patients who were accessing hospital care for other reasons.

The move to close public spaces

In the late 1800s and early 1900s, New York City, like Venice, used its islands to quarantine the sick. Even Ellis Island was used as a quarantine centre for immigrants. Many a hopeful immigrant died in the Contagious Disease Hospital there without ever setting foot in the United States.

It's in New York that we begin to see a new addition to the arsenal of tactics public health officials deployed against epidemics. When a severe polio outbreak struck the city in 1916, authorities took pre-emptive measures to prevent disease transmission. Since polio primarily affects children, the city shut down all the places children gather, like parks, playgrounds, and movie theatres.

Two years later, during the influenza pandemic of 1918, the health commissioner of St. Louisordered the closure of schools, churches, restaurantsand every other type of public meeting place just two days after the first cases of influenza appeared in the city.

In both New York and St. Louis, officials reasoned that sick residents could spread disease before their symptoms became so severe that they sought treatment and were quarantined. By closing public spaces, authorities could limit the extent to which people were able to interact and thereby stave off infections.

During the 1918 flu pandemic, the effect of these measures was striking: St. Louis flattened its curve and weathered the pandemic well compared with other American cities.

These are the examples we're following today, and they show an evolution in how we manage pandemics.

• Social history and so much more: Browse through more work by Ainsley Hawthorn

We've progressed from isolating the sick, to preventively quarantining travellers from disease-affected areas, to limiting interactions between people who seem healthy in the knowledge that they may in fact be infectious and asymptomatic.

Using the wisdom we've gained from past pandemics, health officials are leveraging all three of these strategies today to limit the spread of COVID-19.

Read more from CBC Newfoundland and Labrador