In the context of public health emergency preparedness and response (PHEPR), quarantine is a restriction on the movement of people, animals, goods, or environments that are intended to protect against the spread of disease or pests. Quarantine is distinct from isolation, which restricts the movement of people who are confirmed to be infected with a disease.
Quarantine is only recommended as a practice during an outbreak when it is expected to reduce disease transmission significantly, and the benefits of quarantine outweigh its potential harms. Implementing quarantine during an outbreak requires balancing the need for vigilance against the potential for undue hardship, including social distancing, loss of income, and disruption to family life.
The effectiveness of quarantine depends on its duration and its targeted population, but is generally only feasible if it is limited to the incubation period or less of that for the pathogen to which exposure has occurred. Quarantine may also be more effective if it is implemented early in the disease course or if there is a vaccine or prophylactic treatment available.
The effectiveness of quarantine may also be enhanced by implementing contact surveillance, which monitors contacts for signs and symptoms of infection and ensures that they seek appropriate evaluation and care, and by ensuring that people under quarantine have adequate support in the form of food, shelter, transportation and other essential services. Additionally, a clear communication and transparent approach to quarantine can enhance public trust. People under quarantine should be informed of the rationale behind quarantine, and they should be given the opportunity to appeal.