ACEP COVID-19 Field Guide

Updated May 11, 2023 at the CDC’s web page

If you were exposed to COVID-19, you should start taking precautions.

If you have COVID-19, you can spread the virus to others. There are precautions you can take to prevent spreading it to others: isolation, masking, and avoiding contact with people who are at high risk of getting very sick. Isolation is used to separate people with confirmed or suspected COVID-19 from those without COVID-19.

These recommendations do not change based on COVID-19 hospital admission levels. If you have COVID-19, also see additional information on treatments that may be available to you.

This information is intended for a general audience. Health care professionals should see “Ending Isolation and Precautions for People with COVID-19.” This CDC guidance is meant to supplement — not replace — any federal, state, local, territorial, or tribal health and safety laws, rules, and regulations.

When to isolate

Regardless of your vaccination status, you should isolate from others when you have COVID-19.

You should also isolate if you are sick and suspect that you have COVID-19 but do not yet have test results. If your results are positive, follow the full isolation recommendations below. If your results are negative, you can end your isolation.

When you have COVID-19, isolation is counted in days, as follows:

If you had no symptoms:

• Day 0 is the day you were tested (not the day you received your positive test result).
• Day 1 is the first full day after the day you were tested.
• If you develop symptoms within 10 days of when you were tested, the clock restarts at day 0 on the day of symptom onset.

If you had symptoms:

• Day 0 of isolation is the day of symptom onset, regardless of when you tested positive.
• Day 1 is the first full day after the day your symptoms started.

Isolation

If you test positive for COVID-19, stay home for at least 5 days and isolate from others in your home.

You are likely most infectious during these first 5 days.

• Wear a high-quality mask if you must be around others at home and in public.
• Do not go places where you are unable to wear a mask.
• Do not travel.
• Stay home and separate from others as much as possible.
• Use a separate bathroom, if possible.
• Take steps to improve ventilation at home, if possible.
• Don’t share personal household items, like cups, towels, and utensils.
• Monitor your symptoms. If you have an emergency warning sign (like trouble breathing), seek emergency medical care immediately.
• Learn more about what to do if you have COVID-19.

Ending isolation

End isolation based on how serious your COVID-19 symptoms were. Loss of taste and smell may persist for weeks or months after recovery and need not delay the end of isolation.

If you had no symptoms, you may end isolation after day 5.

If you had symptoms and:

• Your symptoms are improving, you may end isolation after day 5 if you are fever free for 24 hours (without the use of fever-reducing medication).
• Your symptoms are not improving, continue to isolate until you are fever free for 24 hours (without the use of fever-reducing medication) and your symptoms are improving.

If you had symptoms and had:

• Moderate illness (you experienced shortness of breath or had difficulty breathing), you need to isolate through day 10.
• Severe illness (you were hospitalized) or have a weakened immune system, you need to isolate through day 10. Consult your doctor before ending isolation. Ending isolation without a viral test may not be an option for you.

If you are unsure if your symptoms are moderate or severe or if you have a weakened immune system, talk to a physician for further guidance.

Regardless of when you end isolation, until at least day 11:

• Avoid being around people who are more likely to get very sick from COVID-19.
• Remember to wear a high-quality mask when indoors around others at home and in public.
• Do not go places where you are unable to wear a mask until you are able to discontinue masking.

Removing your mask

After you have ended isolation, when you are feeling better (no fever without the use of fever-reducing medications and symptoms improving):

• Wear your mask through day 10; or
• If you have access to antigen tests, you should consider using them. With two sequential negative tests 48 hours apart, you may remove your mask sooner than day 10.

If your antigen test results are positive, you may still be infectious. You should continue wearing a mask and wait at least 48 hours before taking another test. Continue taking antigen tests at least 48 hours apart until you have two sequential negative results. You may need to continue wearing a mask and testing beyond day 10.

After you have ended isolation, if your COVID-19 symptoms recur or worsen, restart your isolation at day 0. Talk to a physician if you have questions about your symptoms or when to end isolation.