ACEP COVID-19 Field Guide

Self-isolation when sick or after a known COVID-19 exposure can reduce the likelihood of infecting other people and can encourage infected individuals to rest and recover. As of 2023, the CDC has updated its guidance on isolation when infected with COVID-19 in its “Isolation and Precautions for People with COVID-19.”

How to self-isolate

Stay in your room or apartment for at least 5 days when you have COVID-19, regardless of your vaccination status. You are likely most infectious during these first 5 days.

If you are sick and suspect you have COVID-19 but don’t have your test results yet, still isolate yourself while waiting for results. If they return positive, follow the isolation recommendations below. If your test results return negative, you can end your isolation.

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

• If you have no symptoms:
  • Day 0 is the day you were tested (not the day you received your positive test result); and
  • Day 1 is the first full day following 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 have symptoms:
  • Day 0 of isolation is the day of symptom onset, regardless of when you tested positive; and
  • Day 1 is the first full day after the day your symptoms started.

Isolation recommendations

Do not travel or go to work, classes, athletic events, or other social or religious gatherings. If you must be around other people, wear a high-quality (N95 or N100) mask. Stay at least 6 feet away from other individuals.

Ensure your household members stay in another room and limit contact with you as much as possible. If possible, household members should use a separate bedroom and bathroom. Do not share your personal items like cups, towels, utensils, or bedding. Thoroughly wash these items after using them.

Ensure that shared spaces in the home have good airflow through either air-conditioning or an open window, as the weather permits. Ideally, air from the isolation room should not return to the rest of the home. An open window or exhaust fan can keep contaminated air away from others.

Cover coughs and sneezes with your upper sleeve or a tissue. Immediately discard any used tissues in a trash bin. Never cough in the direction of someone else. Also avoid touching your eyes, nose, and mouth with unwashed hands.

Perform hand hygiene frequently, especially after coughing, sneezing, or throwing a used tissue in the garbage. Wash your hands often with soap and water for at least 20 seconds or use an alcohol-based hand sanitizer that contains 60% to 95% alcohol, covering all surfaces of your hands and rubbing them together until they feel dry. Soap and water are preferred for the best hand hygiene because, although COVID-19 is killed by alcohol-based hand sanitizer, some other pathogens are resistant to it.

Keep your surroundings clean. Clean surfaces that you share with others — such as counters, tabletops, doorknobs, bathroom fixtures, toilets, phones, keyboards, tablets, bedside tables, and any other object that you may have sneezed or coughed on — with a standard household disinfectant like Clorox wipes. Wash your hands after cleaning the area.

Guidance for cleaning and disinfecting

When available, follow the manufacturer’s instructions for all cleaning and disinfection products regarding concentration, application method, contact time, and so on.

• Hard (nonporous) surfaces:
  • Wear disposable gloves when cleaning and disinfecting surfaces. Gloves should be discarded after each cleaning. If reusable gloves are used, they should be dedicated to cleaning and disinfecting surfaces with COVID-19 and should not be used for other purposes. Wash your hands immediately after gloves are removed.
  • If surfaces are dirty, they should be cleaned using a detergent or soap and water prior to disinfection.
  • For disinfection, most of the common Environmental Protection Agency–registered (EPA-registered) household disinfectants are effective. A list of EPA-approved products that are effective against COVID-19 is available here.
    • Additionally, diluted household bleach solutions (at least 1,000 ppm sodium hypochlorite) can be used if appropriate for the surface. Follow manufacturer’s instructions for application, ensuring a contact time of at least 1 minute, and allow for proper ventilation during and after application. Check that the product is not past its expiration date, otherwise it will not be effective. Never mix household bleach with ammonia or any other cleaner. Doing so creates toxic gases.
• Soft (porous) surfaces:
  • For soft (porous) surfaces, such as carpeted floor, rugs, and drapes, remove any visible contamination and clean with appropriate cleaners that are indicated for these surfaces. After cleaning, launder items as appropriate in accordance with the manufacturer’s instructions. Use the warmest appropriate water temperature and then dry the items completely.
  • Otherwise, use products that are EPA-approved for COVID-19 and suitable for porous surfaces.
• Electronics:
  • Remove any visible contamination from electronics like cell phones, tablets, touch screens, remote controls, and keyboards.
  • Consider using wipeable covers for electronics.
  • If no electronic manufacturer guidance is available, consider using alcohol-based wipes or sprays that contain at least 70% alcohol to disinfect touch screens. Dry surfaces thoroughly to avoid pooling of liquids.
• Linens, clothing, and other items that go in the laundry:
  • Wear disposable gloves when handling dirty laundry from an ill person and discard the gloves after each use. If using reusable gloves, dedicate them to COVID-19 cleaning only; do not use them for any other household cleaning purposes. Wash your hands immediately after gloves are removed.
  • If no gloves are used when handling dirty laundry, be sure to wash your hands immediately afterward.
  • Do not shake dirty laundry. Doing so will disperse the virus through the air.
  • Launder items as appropriate in accordance with the manufacturer’s instructions.
    • Use the hottest water temperature appropriate for the items and dry the items completely.
  • If hot water is used to clean laundry, laundry from an ill person can be washed with other people’s items.
  • Clean and disinfect clothes hampers according to the above guidance based on whether the surface is porous or nonporous. If possible, consider placing either a disposable or washable bag liner in the hamper.

HVAC, ventilation, and filtration

The ventilation and filtration provided by heating, ventilating, and air-conditioning (HVAC) systems can reduce the airborne concentration of COVID-19, which can reduce the risk of transmission through the air. However, running your HVAC system, using an air purifier or a portable air cleaner, and increasing ventilation are not enough to protect you and your family from COVID-19.

• Check that your HVAC filter is correctly in place and consider upgrading the filter to the highest-rated one that your system can accommodate (consult your HVAC manual or an HVAC professional for details).
• HVAC systems only filter the air when the fan is running, so run the system fan for longer times or continuously. Many systems can be set to run the fan without running the heating or air-conditioning.
• When used properly, air purifiers can help reduce airborne contaminants, including viruses, in a home or confined space.
• Improve ventilation and indoor air quality by letting in air from outside:
  • Open the windows and screen doors, if possible.
  • Operate a window air conditioner that has an outdoor air intake or vent, with the vent open.
  • Open the outside air intake of the HVAC system, if yours has one (this is uncommon).
  • Operate a bathroom fan when the bathroom is in use or continuously, if possible.
  • Avoid these actions when outdoor air pollution is high or when it makes your home too cold, hot, or humid.
• Care should be taken with portable ventilation equipment, like fans, to minimize air blowing directly from one person to another to reduce the potential spread of any airborne or aerosolized viruses.
• Use of ozone generators in occupied spaces is not recommended.
  • When used at concentrations that do not exceed public health standards, ozone applied to indoor air does not effectively remove viruses, bacteria, mold, or other biological pollutants.

Additional information is available in the CDC’s “Cleaning and Disinfection for Households. Interim Recommendations for U.S. Households with Suspected or Confirmed Coronavirus Disease 2019 (COVID-19).”

Discontinuing isolation after COVID-19 infection

Ending isolation depends on the severity of COVID-19 symptoms. Loss of taste and smell can persist for weeks or months after recovery and should not delay the end of isolation.

• No symptoms:
  • Asymptomatic individuals can end their isolation after day 5.
• Mild illness:
  • Symptomatic individuals can also stop isolating after day 5 if their symptoms are improving and they are fever-free for 24 hours without the use of fever-reducing medications.
  • If symptoms are not improving, isolation should continue until symptoms start improving and no fever is present for 24 hours without using fever-reducing medications.
• Moderate illness:
  • Symptomatic individuals who had moderate illness, characterized by shortness of breath or difficulty breathing, should isolate through day 10.
  • If symptoms are not improving, isolation should continue until symptoms start improving and no fever is present for 24 hours without using fever-reducing medications.
• Severe illness:
  • Symptomatic individuals who had severe illness (required hospitalization) or who have a weakened immune system should isolate through day 10. They should consult their doctor and may require a viral test before ending their isolation.

Mild illness includes symptoms of fever, cough, sore throat, malaise, headache, and muscle pain without shortness of breath, dyspnea, or abnormal chest imaging. Moderate illness is characterized by evidence of lower respiratory disease (through clinical assessment or imaging) and an SpO₂ reading greater than or equal to 94% on room air at sea level. Individuals with severe illness have a respiratory frequency greater than 30 breaths per minute, an SpO₂ reading less than 94% on room air at sea level (or, for patients with chronic hypoxemia, a decrease from baseline of >3%), a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO₂/FiO₂) less than 300 mm Hg, or lung infiltrates greater than 50%. Critical illness is defined as respiratory failure, septic shock, or multiple organ dysfunction. A health care clinician can help determine your symptom severity if you are uncertain of when to end isolation.

You should continue wearing a mask when around others through day 10, unless you have had two sequential negative antigen tests at least 48 hours apart. If testing returns positive, continue to test, waiting at least 48 hours between each test, until two sequential negative tests are obtained. If your test stays positive beyond day 10, continue wearing a mask around other people.

You should also wait until at least day 11 before being around people who are at a higher risk of severe illness from the virus.

Isolation should restart at day 0 if COVID-19 symptoms recur or worsen after the first round of isolation has ended.