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How long you’re contagious, when to quarantine, and more – NBC Chicago

As people continue to recover from holiday gatherings and others return to work in the New Year, many wonder what the timeline looks like if they develop a COVID-19 infection or are exposed to someone. ‘one who has it.

When are people with coronavirus most contagious and how long can they spread it? When should you get tested after exposure and how long should you quarantine, if applicable?

Here is what we know.

When are people with COVID most contagious?

The Centers for Disease Control and Prevention released new guidelines last month, shifting the timing of isolation and quarantine, as some experts say the time frame during which people are most contagious is earlier.

“It takes less time from the time a person is exposed to COVID to potentially develop an infection. It takes less time to develop symptoms, it takes less time for a person to be infectious, and for many people it takes less time to recover This is largely due to the fact that many more people are vaccinated, ”said Dr. Allison Arwady, commissioner of the Chicago Department of Public Health.

For those who have no symptoms, CDC guidelines say they are considered contagious at least two days before they test positive.

“It has to do with the CDC data which really showed after seven days that there was virtually no risk of transmission at this point,” Arwady said. “And in that five to seven day window, you know, it’s depending on whether people have been vaccinated, the underlying conditions, etc., but the risk goes down a lot and the feeling is that in the general population, combined with masking, etc. the risk is really very low. “

When is the best time to get tested after exposure?

The CDC says anyone who may have been exposed to someone with COVID should be tested five days after exposure, or as soon as symptoms appear.

“If symptoms appear, individuals should immediately self-quarantine until a negative test confirms the symptoms are not attributable to COVID-19,” the guide said.

Illinois Department of Public Health Director Dr Ngozi Ezike said incubation times could change, but those who test early should continue to test even if they test negative.

“Maybe we’re hearing that the incubation time could be a bit shorter. So maybe you would test at two days,” Ezike said. “Obviously, if you’re symptomatic, you test right away. But you know, if you want to test at two days, but that negative test… the two days shouldn’t make you think, ‘Ah well, I’m clear.’ You know you might want to get tested again and of course you can’t ignore the symptoms – sore throat, headaches, all kinds of symptoms – anything new can be a symptom of this new disease. . ”

How quickly can symptoms appear?

According to previous CDC guidelines, symptoms of COVID can appear between two and 14 days after a person has been exposed to the virus.

Anyone with symptoms should get tested for COVID-19.

How long should you quarantine or isolate?

First, those who believe they have been in contact with someone who has COVID and who is not vaccinated should self-quarantine. People who test positive, regardless of their vaccination status, should self-isolate, according to the Centers for Disease Control and Prevention.

Here is the breakdown:


Those who have been within 6 feet of a person with COVID for a cumulative total of at least 15 minutes in a 24-hour period must self-quarantine for five days if they are not vaccinated or more than six months from their second dose, according to updated CDC guidelines released Monday.

After this period is over, they must use a strict mask for an additional five days.

Previously, the CDC had said that people who were not fully vaccinated and had close contact with an infected person were required to stay home for at least 10 days.

Prior to last month, fully vaccinated people – whom the CDC defined as having two doses of the Pfizer or Moderna vaccine, or one dose of the Johnson & Johnson vaccine – could be exempt from quarantine.

Those who are both fully vaccinated and boosted do not need to self-quarantine if they are in close contact with someone with COVID, but must wear a mask for at least 10 days after exposure. The same goes for those who are fully vaccinated and are not yet eligible for their booster.

However, local health authorities can also make the final decision on the duration of a quarantine. And testing can play a role.

The Illinois Department of Health has said it will adopt the CDC’s revised isolation and quarantine guidelines for COVID.

In Chicago, those traveling to or from certain parts of the country and are not vaccinated are required to self-quarantine upon arrival in the city, but the length of time they need to do so depends on whether they are having or not a COVID test.


People positive for COVID should stay home for five days, the CDC said last month, changing the guidelines from the previously recommended 10 days.

At the end of the period, if you have no symptoms, you can resume your normal activities but must wear a mask everywhere – even in the house around others – for at least five more days.

If you are still showing symptoms after five days of isolation, stay home until you feel better, then begin your five days of all-day mask wear.

So how do you calculate your period of isolation?

According to the CDC, “Day 0 is your first day of symptoms.” This means that Day 1 is the first full day after your symptoms appear.

For those who test positive for COVID but have no symptoms, day 0 is the day of the positive test. Those who develop symptoms after testing positive, however, must restart their calculations, with day 0 becoming the first day of symptoms.

When to call a doctor

The CDC is urging those who have or may have COVID to watch for emergency warning signs and seek immediate medical attention if they have any symptoms, including:

  • Difficulty in breathing
  • Persistent pain or pressure in the chest
  • New confusion
  • Inability to wake up or stay awake
  • Pale, gray or blue skin, lips or nail beds, depending on skin tone

“This list does not contain all possible symptoms,” says the CDC. “Please call your doctor for any other symptoms that are serious or of concern to you.”

You can also let the operator know that you think you or someone you care for has COVID.

What if you test positive using a home test?

Those who test positive using a home test are urged to follow the latest CDC guidelines and report the results to their health care provider, who is responsible for reporting test results to the department. state health.

According to the Chicago area health services, people should assume the test results are accurate and should isolate themselves from others to reduce the risk of the virus spreading.

“If you test positive for COVID-19, you need to self-isolate,” Arwady said. “There is no need to repeat a positive home test in a medical setting. We don’t want people going to the emergency room just to get tested. Treat a positive like a positive, stay home and isolate for a while. five days. “

When can you be around other people after you have been diagnosed with COVID?

If you’ve had symptoms, the CDC says you can be with others after you’ve been isolated for five days and stopped showing symptoms. However, you should continue to wear masks for five days to minimize the risk to others.

NBC Chicago

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