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How Long Is COVID-19 Contagious?

Reviewed on 12/14/2020

What Is COVID-19?

COVID-19 (coronavirus disease) can be contagious for weeks or longer, depending on the patient. The time from infection to the start of symptoms (incubation) ranges from four days to two weeks, though patients are contagious before symptoms develop. Follow CDC guidelines for self-quarantining if you have a coronavirus infection.
COVID-19 (coronavirus disease) can be contagious for weeks or longer, depending on the patient. The time from infection to the start of symptoms (incubation) ranges from four days to two weeks, though patients are contagious before symptoms develop. Follow CDC guidelines for self-quarantining if you have a coronavirus infection.

COVID-19 (coronavirus disease 2019) is a novel (new) coronavirus, one not previously identified in humans, responsible for an outbreak of respiratory illness that became a global pandemic in 2020. COVID-19 is different from other coronaviruses that cause mild illness, such as the common cold.

What Are Symptoms of COVID-19?

Early symptoms of COVID-19 (coronavirus disease 2019) appear about 2 to 14 days after exposure and include:

Other symptoms of COVID-19 include:

Less common symptoms of COVID-19 may include: 

Emergency warning signs of COVID-19 that require immediate medical attention (call 9-1-1 or go to a hospital’s emergency department): 

  • Difficulty breathing
  • Persistent pain or pressure in the chest
  • Bluish lips or face
  • New confusion or inability to arouse

What Causes COVID-19?

COVID-19 (coronavirus disease 2019) is caused by a novel strain of coronavirus that is transmitted from person-to-person through respiratory droplets that are propelled into the air when an infected person sneezes or coughs

Less commonly, COVID-19 may be transmitted when a person touches a surface or object that has the virus on it, and then touches their mouth, nose, or eyes.

How Long Is COVID-19 Contagious?

COVID-19 (coronavirus disease 2019) can be contagious for weeks or longer, depending on how sick a patient is. 

The incubation period for COVID-19 (the time from infection to the start of symptoms) ranges from 4 days to 2 weeks, though patients are believed to be contagious before symptoms develop. 

The Centers for Disease Control (CDC) advises that if you had a mild to moderate case of COVID-19 and are recovering, you can be around other people if: 

  • 10 days have passed since symptoms first appeared AND
  • 24 hours have passed with no fever, without the use of fever-reducing medications (this means the fever must go away on its own) AND
  • Other COVID-19 symptoms are improving
    • Loss of taste or smell may be present for weeks or months and does not require quarantine if those symptoms persist

Patients who had a severe case of COVID-19 may need to quarantine for up to 20 days after symptoms first appear. 

How Is COVID-19 Diagnosed?

COVID-19 (coronavirus disease 2019) is diagnosed with a medical history (including any recent known exposure to COVID-19) and physical exam, looking for symptoms of COVID-19. 

If COVID-19 is suspected there are several tests that can be used to diagnose the virus. A long swab is used to take a sample from the nose or throat, which is then sent to a lab for testing to diagnose the illness. Some viral tests are rapid and results are available within a few hours. Other tests may take several days to receive results. 

  • PCR tests (genetic or molecular test) 
  • Antigen test

To determine if a person had a past COVID-19 infection, an antibody test may be used. Antibody tests are not used to diagnose current infections because it takes up to 3 weeks following infection for the body to produce antibodies to the virus. When a person has antibodies to COVID-19 they may have some protection against re-infection, however, researchers do not yet know how much protection antibodies provide or for how long any protections might last.

What Is the Treatment for COVID-19?

There is no current cure for COVID-19 (coronavirus disease 2019) and treatment is aimed at relieving symptoms in mild to moderate cases. 

Patients with mild to moderate illness are usually advised to remain home and self-isolate for up to 14 days to avoid spreading the virus. Treatments for mild to moderate COVID-19 symptoms include:

  • Over-the-counter (OTC) pain relievers 
  • Cough suppressants
  • Rest
  • Drinking plenty of fluids 

A medication called bamlanivimab, which is a monoclonal antibody, has received Emergency Use Authorization (EUA) from the Food and Drug Administration (FDA) to treat mild-to-moderate COVID-19 in adult and pediatric patients who are at high risk for progressing to severe COVID-19 and/or hospitalization. Bamlanivimab is not indicated for use in severe cases.

For more severe COVID-19 cases, patients may require hospitalization. Treatments may include:

  • Antiviral therapy with remdesivir 
  • Corticosteroids 
  • Immunotherapy 
    • Convalescent plasma
    • Immunoglobulin products
    • Interleukin inhibitors
    • Interferons
    • Kinase inhibitors
  • Antithrombotic therapy: anticoagulants and antiplatelet therapy 
  • High-flow nasal cannula (HFNC) oxygen 
  • Tracheal intubation and mechanical ventilation 

Current guidelines neither recommend nor advise against the use of vitamin C, vitamin D, or zinc for coronavirus disease (COVID-19). Zinc should not be taken in doses above the recommended daily allowance (RDA) due to the risk of toxicity. 

Studies on hydroxychloroquine have shown it to be ineffective with a high risk of fatal heart arrythmias, and it is not recommended to treat COVID-19.

What Are Complications of COVID-19?

Doctors and researchers are still learning about the effects of COVID-19 (coronavirus disease 2019) on the body. Lingering complications of the illness are being discovered well after patients have recovered. 

Known COVID-19 complications include:

How Do You Prevent COVID-19?

Several vaccines to prevent COVID-19 are currently in development. Five are in phase 3 clinical trials in the U.S. The Pfizer mRNA vaccine was approved for Emergency Use Authorization (EUA) from the Food and Drug Administration (FDA). Doses are expected to first be given to healthcare workers and high-risk patients, such as nursing home residents.

To protect yourself from getting COVID-19 (coronavirus disease 2019): 

  • Wash hands frequently with soap and water for at least 20 seconds. 
  • If soap and water are not available, use hand sanitizer with at least 60% alcohol and use a sufficient amount to rub in for 20 seconds.
  • Do not touch your mouth, nose, or eyes with unwashed hands.
  • Avoid close contact with anyone who has been diagnosed with COVID-19. 
  • If there is an outbreak in your community, stay at home and limit close contact with others. 
  • Maintain a distance of at least 6 feet from other people. 
  • Wear a face mask when out in public. 

To protect others:

  • Stay home if you’re sick, unless you need medical care. 
  • Wear a face mask around other people if you are sick. 
  • Cover your mouth and nose with a tissue or the inside of your elbow when you cough or sneeze. Discard used tissues. Immediately wash hands with soap and water for at least 20 seconds or use a hand sanitizer with at least 60% alcohol if soap and water is not available. 
  • Clean and disinfect frequently touched surfaces daily. This includes countertops, doorknobs, handles, tables, light switches, phones, keyboards, toilets, faucets, and sinks. Use EPA-registered household disinfectants.

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Reviewed on 12/14/2020