What Is the Protocol for Quarantine?

Quarantine is a tool used to prevent the spread of disease by keeping people who might be sick away from those who are healthy. This can either be done through a medical directive from a doctor or, less commonly, through a court or federal order. How long someone should be separated—and where—will depend on the disease and who ordered the quarantine. 

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What Is a Quarantine?

Quarantine is a process used by healthcare workers and public health officials to limit the spread of contagious diseases by separating people who have been exposed to a particular disease from those who haven't.

Quarantines can be formal—where health officials remove individuals from the general population and keep them in a special (usually guarded) location—or informal, such as when a healthcare provider recommends people stay home in a “self-quarantine” to avoid potentially spreading the disease to others. 

History of Quarantines

Quarantines have been used to protect public health since the 14th century, when the fear of the “Black Death” (or plague) in the Middle Ages prompted Venetian authorities to require ships to stay anchored for 40 days—long enough for them to be certain no one on board was sick. Back then, Italians called it quaranta giorni (or “40 days”), which is where the English word for “quarantine” comes from.

In the U.S., states and local governments are often in charge of “police power” functions—that is, enacting laws and policies that protect the health and safety of people inside their borders—but the federal government also has the ability to enforce quarantine and isolation orders. Legally, federal health officials can detain anyone they think could pose a significant risk to public health. This, however, is extremely rare. 

The Difference Between Quarantine and Isolation

While you might see the words “quarantine” and “isolation” used interchangeably, they actually refer to two separate processes. Both isolation and quarantine can help limit the spread of disease, but the process used depends on whether someone is actively sick or not.

  • Someone who is already sick with a communicable disease is separated from healthy people.

  • Someone who is not yet sick—but has been exposed to a contagious disease— is separated from healthy people.


Isolation is when someone who is already sick with a communicable disease is separated from healthy individuals until they are no longer contagious. 

Medical professionals will sometimes refer to “isolation” as keeping a patient in a negative pressure room, where fresh air can flow into the room, but contaminated air cannot flow out. These rooms are typically only used for airborne germs, such as measles, that can live floating in the air for an extended period of time.

But an individual does not necessarily have to be in a negative pressure room in order to be isolated from the general population. They might be moved to a particular area of the hospital, for example, or be asked to stay in their own home, away from other people. Depending on the situation, extensive steps may be taken to prevent a person who is sick from passing the pathogen to other people, such as being guarded in a special facility. 


Quarantine, on the other hand, is used when someone who has been exposed to a contagious disease—but who is not yet sick—is separated from healthy people or asked to limit their movements, just in case they develop an infection. This is particularly important for illnesses where people can spread the germ to others before developing symptoms or without ever feeling sick. 

The word “quarantine” has been used only for court orders, where individuals are legally required to stay at home or in a specific facility. More recently, however, the term has been expanded to include medical orders made by doctors or recommendations from health officials that individuals stay in their homes if they've come into contact with someone infected with a particular disease (or think they might have). 

What Happens When Someone Is Quarantined?

What happens when someone is quarantined depends on whether the quarantine is the result of a court order or a medical directive. But, in general, a quarantine protocol involves the following steps: 

  • Individuals exposed to a disease (or might have been) are separated from the general population for a specific period of time. The length of the quarantine typically depends on the incubation period of the disease—or about how long it takes to develop symptoms after coming into contact with someone who is infected. Individuals can sometimes be grouped together (for example, by family) or placed in individual rooms. For court-ordered quarantines, individuals may be guarded or placed in a special facility during that entire time to prevent them from leaving. For individuals who are asked to self-quarantine in their homes, there might not be a guard or health officials enforcing the quarantine, but it is still important for them to adhere to the quarantine directives. 
  • Quarantined individuals are monitored to see if symptoms develop. In some cases, this involves a doctor, or another healthcare provider, checking on them periodically (even daily) to test them for the disease or check for symptoms. Depending on the specific disease, healthcare providers will likely wear personal protective equipment (PPE) to lower their chances of getting sick themselves. In cases of self-quarantine, an individual is generally asked to monitor their own health status and call a doctor right away if they begin to experience specific signs or symptoms. 
  • If individuals become sick during the quarantine period, they are moved to isolation. Under a court-ordered quarantine, this could mean moving to a healthcare facility or another area that is similarly guarded to prevent individuals from leaving isolation. 
  • If individuals do not become sick during the quarantine period, they are allowed to leave the quarantine area. However, medical providers and health officials might still ask them to contact a doctor right away if symptoms do develop. 

If you're in isolation or quarantine, it's normal to experience feelings of fear, anxiety, sadness, and uncertainty. However, being proactive about your mental health can help keep both your mind and body stronger. Learn about the best online therapy options available to you.

When Can Quarantines or Isolations Be Imposed? 

While it’s not very common, health officials can get a court order to impose a quarantine on individuals. Because a quarantine takes away a person’s freedom of movement, it’s a significant decision not made lightly. It is only enacted when there is a clear risk to public health. 

The Public Health Service Act allows the federal government to enact certain powers, including quarantine, in a public health emergency. By executive order, the president of the U.S. can include a disease for quarantine upon the advice of the secretary of the department of health and human services. Currently, the following diseases can be considered for quarantine:

  • Cholera
  • Diphtheria
  • Infectious tuberculosis
  • Plague
  • Smallpox
  • Yellow Fever
  • Viral hemorrhagic fevers
  • Severe acute respiratory syndrome (or SARS)
  • Flu that can cause a pandemic

The last large-scale federal quarantine order was enacted over a century ago during the 1918-1919 flu pandemic, but smaller events can still result in isolation or quarantine orders. For example, in early 2020, federal health officials quarantined cruise ship passengers in an attempt to limit the spread of COVID-19. Some individuals on board had been potentially exposed to the virus, prompting health officials to place all passengers under federal quarantine for two weeks. 

Can Local Governments Enforce Quarantine or Isolation Protocol? 

While the federal government has the final say if there’s ever a disagreement, state and many local health departments have their own health authority who can enact local quarantines, so long as a judge approves it. 

In some cases, a court order might come after someone was asked to self-quarantine but then ultimately didn’t follow quarantine protocol. For example, a doctor might ask a person with an active tuberculosis infection to isolate themselves in their own home until they are no longer contagious. If the individual refuses to follow the isolation protocol, a local health authority can ask a judge for a court order, requiring an individual to be held in a facility where the protocol can be enforced.  

Are There Consequences of Ignoring Quarantine Protocol? 

Ignoring or refusing to follow quarantine protocol can have serious repercussions, both legally and in terms of public health. 

Legal Ramifications

Breaking a quarantine order can have different legal ramifications, depending on who gave the order and where. States have their own laws dictating how public health laws and protocols should be enforced. However, violating a quarantine is a criminal misdemeanor in most states, and those violating federal quarantine or isolation orders could face fines or jail time.  

In cases of self-quarantines, or those under a medical directive as opposed to a court order, breaking protocol by leaving your home early likely won’t cause you to be arrested, but local health authorities might seek a court order that places you in a facility or legally requires you to comply.  

Public Health Risks 

Even if you’re not under a court-ordered quarantine or are worried about legal risks, it’s still crucial you follow protocol in order to protect the health of those around you. 

If a person is under quarantine, it’s because it’s possible they have been likely exposed to a disease and could spread it to others. Breaking protocol by leaving your home or quarantine facility before the end of the quarantine period could put others at risk of infection and spark an outbreak. 

A Word From Verywell 

Quarantine is a tool used to control the spread of diseases. But because it also limits a person’s movements (and in some cases, liberties), it’s only used when health officials believe there's a high risk to the community as a whole. If a doctor or health official asks you to self-quarantine or isolate yourself in your home for a given period of time, it’s important to follow their instructions closely to limit the chances you pass the disease onto someone else.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. History of quarantine.

  2. Centers for Disease Control and Prevention. Quarantine and isolation: U.S. quarantine stations.

  3. Centers for Disease Control and Prevention. Quarantine and isolation.

  4. Centers for Disease Control and Prevention. Isolation and quarantine.

  5. Centers for Disease Control and Prevention. Quarantine and isolation: Interim guidance for ships on managing suspected coronavirus disease 2019.

  6. Centers for Disease Control and Prevention. Menu of suggested provisions for state tuberculosis prevention and control laws.

Additional Reading

By Robyn Correll, MPH
Robyn Correll, MPH holds a master of public health degree and has over a decade of experience working in the prevention of infectious diseases.