Switzerland put in place a quarantine from July 6th on arrivals from so-called high-risk countries.
Initially, 29 countries were placed on the list.
With coronavirus case numbers rising in regions around the world, the list has expanded to 55 countries as of mid-September.
During this time, while dozens of countries have been added, many have also been removed.
But how does Switzerland decide who makes the list?
Switzerland's coronavirus infection threshold
In order to set a fair and objective metric for placing a country on the 'high-risk' list, Switzerland set the threshold at 60 infections per 100,000 residents over the past 14 days.
This means that the total number of new infections must be calculated over the 14-day period.
If a country breaches the threshold, they are eligible for the list – although the Swiss government will always have the discretion as to whether or not to place it on the list.
On September 15th, for example, Switzerland itself breached the threshold nationwide.
How does this compare internationally?
Different countries have adopted different measures to set quarantine requirements.
In the UK, the rate is 20 per 100,000 residents over the previous seven days.
In Germany, the rate is 50 per 100,000 over the past seven days.
The curious case of France, Germany, Italy and Austria
One example of Switzerland's discretion relates to France, Germany, Italy and Austria.
On September 14th, Switzerland put a quarantine on some arrivals from France – despite Switzerland's western neighbour having breached the coronavirus threshold of 60 new infections per 100,000 residents nationwide weeks before.
This however applied not to the entire country but to arrivals from nine French regions.
Similarly, Vienna was designated high-risk – but not the rest of the country.
France and Austria were broken up into regions rather than considered as a whole country due to the importance of the border regions to the Swiss economy.
In making the announcement, Swiss health minister Alain Berset effectively implied that border regions would remain exempt from quarantine requirements due to the economic and social connections which span both sides of the border.