Quarantine involves physically segregating persons who may have been exposed to a contagious disease from other people for a period of time that is intended to exceed the length of the expected incubation period of the disease. It is important that the people who are quarantined are provided with care and essential services, that their “due process” rights are respected, and that they are monitored for symptoms.
There is moderate certainty of evidence (COE) that quarantine reduces disease transmission and associated morbidity and mortality during an outbreak, but it can also have adverse effects, including increased risk of infection in congregate quarantine settings, psychological harms, and financial hardship for some people placed in isolation. It is recommended that state, local, tribal, and territorial health departments only implement quarantine when necessary, and after careful consideration of the biology of a specific disease, the expected balance of benefits and harms, and the feasibility of implementation.
There is low COE that quarantine reduces disease transmission during an outbreak, but the quality of the evidence is poor. Several studies have used inappropriate outcome measures, and other issues have contributed to inconsistent results. The studies that have used valid outcomes typically find that quarantine is effective. There is moderate COE that adherence to quarantine is important for public health success. Adherence is influenced by social factors that can be addressed through various implementation strategies. Some studies have found that using risk communication and messaging, as well as providing employment leave to those who must comply with quarantine, improves adherence.