With various disease containment measures being implemented, awareness of key terms is vital. This article provides basic information on quarantine.
Incubation period: The time between acquiring an infection and manifestation of illness. Usually, this is not a single figure, but a range of values denoting the shortest and longest time from acquisition of infection to manifestation of illness. It varies from disease to disease.
Quarantine station: A designated establishment at a major port of entry where public health personnel screen incoming travellers for specific conditions, and place them under quarantine on site if criteria for the same are met. A list of quarantine stations in the USA is available on the Centres for Disease Control (CDC) website.
Quarantine: A disease containment measure that separates and restricts the movement of well people who were exposed to a contagious disease to see if they become sick. The word “quarantine” derives from the Italian quaranta dei (forty days), a reference to the Venetian practice of segregating ships with potentially infected persons for 40 days during the plague pandemic in the 14th century. This measure aims to protect unexposed/ uninfected people from acquiring infection.
Indications for quarantine
Outbreak/ epidemic/ pandemic of specified diseases. The list is usually informed by the International Health Regulations (IHR), and often includes:
- Yellow fever
- Viral haemorrhagic fevers (Marburg, Ebola, etc.)
- Severe Acute Respiratory Syndromes (SARS, MERS-CoV, COVID-19, etc.)
Forms of Quarantine
Absolute/ Complete quarantine: Complete limitation of freedom of movement for a period equal to the longest usual incubation period of the disease.
Modified/ Flexible quarantine: Selective or partial limitation of movement, based on known differences in susceptibility. Examples include:
- Personal surveillance
- Medical supervision
- Segregation (individual/ group)
- Establishment of a cordon sanitaire (a boundary zone between uninfected and infected or exposed persons)
Types of Quarantine
- Work quarantine: Generally applied to healthcare workers, this is a form of flexible quarantine in which the quarantined personnel continue to perform their shifts at work, but unnecessary contacts with other persons/ units in hospital are avoided, and preventive measures to avoid spreading the infection are taken.
- Home quarantine: Exposed individuals remain at home during the period of quarantine (as against an institution (like hospitals).
- Reverse quarantine: Here, vulnerable populations (like those in a shelter/ old-age home) prohibit anyone from outside to come in (physical) contact with them so they may avoid receiving the infection.
- Voluntary (Self) quarantine: Here, an individual who has recently been exposed to an infected person, or is travelling from a place where the disease in question is present/ spreading, stays at home for the duration of quarantine and
- Follows standard hygiene measures
- Does not share clothes/ utensils
- Stays at home
- Does not have visitors
- Follows other instructions as applicable (like staying at least 2 metres away from other members of the household in the case of COVID-19, for instance)
Duration of quarantine
Generally this is equal to the longest usual incubation period of the disease.
Enforcement of quarantine
This may be achieved through two ways:
Here, quarantine is imposed on people through the use of police, paramilitary or military personnel.
Advantage: Strict enforcement of quarantine is possible
Disadvantage: Individual/ public refusal to accept quarantine restrictions may lead to conflict.
Example: Deployment of military by Angolan government to enforce quarantine during an outbreak of Marburg virus. This lead to serious violence against public health workers.
Here, quarantine is enforced through collaboration with local leaders and influencers.
Advantage: Rapid and effective when key leaders are involved and convinced to support quarantine early in the outbreak
Disadvantage: Identifying and convincing local leaders may not always be easy.
Example: Rapid control of the 2000 Ebola epidemic in Uganda by collaborating with traditional healers to modify high-risk burial practices.
Main requirements for effective quarantine
- Education to build public trust in health authorities
- Facilities for quarantine. This includes the availability of quarantine stations at major ports of entry into a country/ region; adequate testing/ screening facilities (this includes the availability of clear case definitions and guidance on screening/ testing, etc.); arrangements to provide food/ rations to those quarantined (at home/ hospital/work); adequate facilities to ensure each quarantined person does not come in contact with others in quarantine/isolation or unexposed persons; availability of personal protective equipment appropriate for the disease in question
- Compensation and job security for quarantined workers. Legal protection for job security and income replacement caused by quarantine is a crucial pre-requisite. In countries having a federal structure of government, related laws will have to be enacted at the appropriate levels (Centre/ State).
- Incentives to health care workers to maintain their morale in the face of increased risk and to pay greater attention to infection control practices.
- Large-scale compliance with quarantine restrictions (the maximum effectiveness of quarantine is reached when compliance is 90%). Public cooperation is critical, and will be influenced by the presence of conditions mentioned above.
Impediments to compliance with quarantine
- Loss of income during quarantine
- Loss of employment after quarantine (regardless of whether one developed disease or not)
- Stigma and discrimination during and after being placed under quarantine
Restriction of movement and segregation of exposed/ infected individuals during an epidemic is justified on the grounds that it is for the greater good of society. However, this infringes on basic human rights and liberties.
Similarly, contact tracing and notification of third parties may infringe upon individual privacy.
Mandatory testing, mandatory treatment can also interfere with an individual’s right to consent to medical procedures.
Distinction between Isolation and Quarantine
Isolation is the segregation of sick/ diseased individuals, while quarantine is applied to well persons who have been exposed to an infected person.
Learning from SARS- Preparing for the next disease outbreak- Workshop Summary:
Link to the CDC page on quarantine: