Non-pharmaceutical intervention (epidemiology) in the context of "Quarantine"

During the early stages of the COVID-19 pandemic, a number of non-pharmaceutical interventions, particularly lockdowns (encompassing stay-at-home orders, curfews, quarantines, cordons sanitaires and similar societal restrictions), were implemented in numerous countries and territories around the world. By April 2020, about half of the world's population was under some form of lockdown, with more than 3.9 billion people in more than 90 countries or territories having been asked or ordered to stay at home by their governments.

In addition to the health effects of lockdown restrictions, researchers had found the lockdowns may have reduced crime and violence by armed non-state actors, such as the Islamic State, and other terrorist groups. In addition, lockdowns had increased the uptake of telecommuting, reduced airborne pollution, and increased adoption of digital payment systems.

In public health, social distancing, also called physical distancing, is a set of non-pharmaceutical interventions or measures intended to prevent the spread of a contagious disease by maintaining a physical distance between people and reducing the number of times people come into close contact with each other. It usually involves keeping a certain distance from others (the distance specified differs from country to country and can change with time) and avoiding gathering together in larger groups.

By minimising the probability that a given uninfected person will come into physical contact with an infected person, the disease transmission can be suppressed, resulting in fewer deaths. The measures may be used in combination with other public health recommendations, such as good respiratory hygiene, use of face masks when necessary, and hand washing. To slow down the spread of infectious diseases and avoid overburdening healthcare systems, particularly during a pandemic, several social-distancing measures have been used, including the closing of schools and workplaces, isolation, quarantine, restricting the movement of people and the cancellation of mass gatherings. Drawbacks of social distancing can include loneliness, reduced productivity and the loss of other benefits associated with human interaction.