Covid-19 – Isolation and Quarantine

The coronavirus disease 2019 (COVID-19) pandemic has everyone learning new public health terminology. Two of those terms, isolation, and quarantine, refer to what a person should do after testing positive for COVID-19 (isolation) or being exposed to someone with COVID-19 (quarantine). Isolating or quarantining protects other people by preventing the sick or possibly sick person from interacting with others and exposing them to a contagious disease.


A quarantine involves sequestering or limiting the movements of people exposed to an infectious disease to prevent its spread. Quarantine is a different concept from isolation. According to the U.S. Centers for Disease Control and Prevention (CDC), a more detailed definition of quarantine is “the separation of a person or group of people reasonably believed to have been exposed to a communicable disease but not yet symptomatic, from others who have not been so exposed, to prevent the possible spread of the communicable disease.””

If you’ve been in contact with someone who has tested positive for infectious disease or is presumed to have an infectious disease, you should self-quarantine. This is because you may have been infected but are not yet showing symptoms. Generally, people sick with an infectious disease are most contagious a few days before symptoms appear through the first few days of being symptomatic. Quarantine gives the person time to see if they are infected or not and distances the potentially sick person from others to stop disease spread.

You may have heard of the term self-quarantine when a person voluntarily quarantines out of caution. This contrasts with the original term quarantine, which traditionally implies that the person is ordered to go into quarantine by someone else, like a public health agency.

For COVID-19, “close contact” with someone who has COVID-19 means:

  • Being within 6 feet for at least 15 minutes
  • Direct physical contact, such as kissing or hugging
  • Sharing utensils or drinking glasses
  • Being exposed to respiratory droplets via coughing or sneezing
  • Caring for someone with COVID-19 at home

Anyone who has had close contact with a person with COVID-19 should quarantine and talk to their doctor.


This depends on what infectious disease the person was exposed to. For example, COVID-19’s symptoms appear 2–14 days after a person was exposed to the virus, so the quarantine period of someone exposed to a person with COVID-19 is 14 days. It is assumed that the quarantine person will begin to have symptoms within those 14 days if they were infected. If they don’t show any symptoms after 14 days, then they likely were not infected.

The term quarantine originated in Venice in the 1300s when ships suspected of carrying infectious diseases (like the plague) were ordered to isolate for 40 days (the “quarant” part of the word refers to 40).


Isolation involves separating a person with a known infectious disease in order to prevent its spread. If a person tests positive for an infectious disease (or is clinically diagnosed with the disease if testing is unavailable), they are separated from others or placed with other persons infected with the same disease (known as cohorting) to prevent spreading the disease to other people.


Just like quarantine, the length of isolation varies with each infectious disease and even each person, depending on the length of their symptoms. For example, the isolation requirements for COVID-19 are to isolate ten days after a person tested positive.

If they are symptomatic, they may end isolation after 10 days if they have not had a fever in the past 24 hours (and have not taken fever-reducing medication) and if their symptoms are improving. If they didn’t have any symptoms, then they can end isolation ten days after their last positive COVID-19 test.

Within hospitals and other health-care facilities, persons with contagious infections are isolated or cohorted according to established criteria, and specific precautions for health-care workers and visitors are determined based upon the nature of the pathogen (disease-causing organism) responsible for the infection.


If a person without symptoms has been tested for infectious disease and is awaiting the results, they should act as if they are positive and begin to self-quarantine until they get their test results back. If the test results are positive, then they should continue in isolation based on public health guidelines. If the test results are negative, then they can stop the self-quarantine.


During quarantine and isolation, a person should avoid contact with people outside of their household and avoid contact with others inside the household. This means they should sleep in a separate bedroom alone and use their bathroom, if possible.

For COVID-19, the sick or quarantined person and other household members should consider wearing masks, especially when the sick or quarantined person interacts with other household members or if they cannot be separated from other household members. Contact with pets should also be avoided or minimized as cats and dogs have contracted COVID-19. The sick or quarantined person should also avoid sharing food, drinks, utensils, dishes, or glasses with other household members.


Quarantine stations are located at 20 ports of entry and land border crossings across the U.S. to limit the entry of infectious diseases into the country and prevent their spread.

These stations are a part of the comprehensive Quarantine System employed as a public health measure from the CDC and CDC’s Division of Global Migration and Quarantine (DGMQ). Medical professionals and CDC public health officers decide whether sick travellers can enter the U.S. and what should be done to prevent the spread of infectious diseases (such as if the traveller needs to go into quarantine or isolation).

According to the CDC, federal isolation and quarantine are authorized for the following communicable diseases: cholera, COVID-19, diphtheria, infectious tuberculosis, plague, smallpox, yellow fever, viral hemorrhagic fevers, severe acute respiratory syndromes, and flu that can cause a pandemic.

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