The Perfect Enemy | When Are You Most Contagious With COVID and How Long Can You Spread It?
August 11, 2022

When Are You Most Contagious With COVID and How Long Can You Spread It?

When Are You Most Contagious With COVID and How Long Can You Spread It?  NBC ChicagoView Full Coverage on Google News

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As COVID-19 cases rise with the emergence of new variants, you may be wondering how long the virus can linger.

The latest guidance from the Centers of Disease Control and Prevention recommends people who contract COVID-19 isolate for at least five days, followed by five days of strict mask use.

Despite the length of positivity and the contagiousness of BA.4 and BA.5 omicron subvariants, Chicago Department of Public Health Commissioner Dr. Allison Arwady said she doesn’t anticipate changes to isolation or quarantine protocols. She did note, however, some people are staying positive longer.

“I wouldn’t say the incubation period is shorter. … It’s been getting shorter compared to what the original was, but we are seeing people often have just upper respiratory symptoms or having a cold, they’re having sore throat sometimes, they’re having fever or not seeing a lot of that severe illness – especially in people who are up to date with vaccine because the secondary part of your immune system kicks in and helps – but we’re seeing people they can stay positive for a little longer,” Arwady said last week.

The risk of spreading COVID drops significantly after Day 10, including for those who have lingering symptoms.

“If you’re mostly feeling well, especially if what is still kind of lingering is a cough or a little bit of cough tends to be the last thing to go away after any virus, it is unlikely that you are still spreading disease,” Dr. Arwady said last week.

Generally, a person with COVID-19 is considered infectious starting two days before they develop symptoms, or two days before the date of their positive test if they do not have symptoms, according to the CDC. Even with the latest subvariants, the isolation guidance remains the same.

As long as their symptoms have improved, most people are no longer contagious five days after they first show symptoms.

However, that’s not true in all cases.

A recent Boston University study revealed that just 17% of people were likely still contagious six days after their first positive tests. But a University of Chicago Medical Center study published earlier this year contradicted CDC recommendations, finding more than 40% of vaccinated health care workers still tested positive for COVID-19 five to 10 days after their symptoms began.

As a precaution, those out of the five-day isolation window should partake in strict mask use for an additional five days, guidance stated.

According to the CDC, data suggests patients with mild-to-moderate COVID-19 remain infectious no longer than 10 days after symptom onset. Those with severe-to-critical illness stemming from a COVID infection likely aren’t infectious 20 days after symptoms first begin.

While they likely won’t be infectious after that, patients could test positive for COVID months after recovering.

PCR tests are “very sensitive,” Arwady previously said, adding they can “stay positive for a long time.”

“They keep picking up dead virus in your nose for sometimes for weeks, but you can’t grow that virus in the lab,” she stated. “You can’t spread it, but it can be positive.”