Quarantine is the restriction of movement or separation of well people who have been exposed to contagious agents before it becomes known whether they will become ill. It is designed to prevent transmission of the infectious agent to others before symptoms appear. It is typically applied to an individual person or group of persons but may be extended to animals or plants. It is often imposed in an attempt to contain a disease outbreak when medical countermeasures are not available or are expected to be inadequate.
Quarrantine can be effective in reducing the spread of disease and thus prevent death, disability and suffering. However, the value of quarantine depends on the characteristics of the pathogen and the circumstances of an outbreak. It is a resource-intensive intervention, and it can lead to psychological harms (moderate certainty of evidence), increased risk of infection in congregate quarantine settings (low COE) and financial hardship for those placed under quarantine (high COE).
It is essential that officials have clear reasons for placing people under quarantine, provide information about protocols and ensure that sufficient supplies are provided. Appeals to altruism can be particularly effective in encouraging people to comply with orders. Keeping the duration of quarantine to a scientifically justifiable length, taking into account the incubation period, and avoiding an overly precautionary approach are also key. Implementation policies should be informed by rapid assessment of the local context, taking into account cultural and economic factors that influence success, and should allow for reasonable modifications to rules and procedures in order to respond to locally assessed needs.