Confused By The CDC's New COVID Isolation Rules? Here's A Clear Guide.

As the omicron coronavirus variant surges across the world, many regions are seeing record-high case numbers. The United States set a new seven-day-average record every day over the past week.

There’s no denying that omicron is significantly more transmissible than previous variants and spreading faster than any other we’ve seen so far. And now, many people who’ve been playing it safe for the entire pandemic are testing positive — not that a diagnosis is any kind of moral referendum.

Scientists are still learning about omicron ― whether it’s inherently less virulent than other strains, how its hospitalization rate compares to previous variants, and what it means for long COVID. The good news is, many studies indicate that omicron causes less severe illness overall, especially in people who have been vaccinated or previously infected.

But if you’re out and about, the not-so-great news is that because omicron is extra contagious, odds are pretty high that sometime in the near future you will test positive and need to isolate at home until your infection clears.

The Centers for Disease Control and Prevention’s guidance for isolating is dense and can be somewhat confusing — especially since the rules seem to be in constant flux based on community transmission levels and people’s vaccination status. But here, we break it down, clear and simple, so you know if, when, and how you need to isolate.

If you test positive for COVID and you do (or don’t) have symptoms...

Regardless of whether you’re fully vaccinated, boosted, partially vaccinated or unvaccinated, if you test positive for COVID-19, you must isolate for five days from symptom onset, per the CDC’s latest guidance.

This means the first full day of symptoms — the day you begin developing symptoms is technically not included in the five-day isolation period. In other words, it doesn’t start on the day you begin to feel off, whether it’s a sore throat later in the day or fatigue; that’s what the CDC refers to as “day zero.”

Here’s an example: Say you start to feel some congestion or a scratchy throat on a Monday afternoon. You suspect you might be infected, but you’re not sure (at this point, though, please stay home to be safe). On Tuesday, you wake up feeling worse ― maybe you have a fever, or your congestion got more intense ― and it continues that way until you go to sleep. The next morning you wake up feeling crummy again, so you take a test and it’s positive. In this scenario, your isolation period doesn’t start from Monday ― Monday is considered day zero. Your first day of the five-day isolation period would be Tuesday, your first full day of symptoms.

The five-day isolation period should also occur if you’re asymptomatic and you test positive. “Once you’ve got a positive test, you’ve got it, you’re in a category where you have virus,” said Bernadette Boden-Albala, the director and founding dean of the University of California, Irvine’s Program in Public Health. If this is the case for you, the five-day period begins the day after you test positive. The actual day you test positive is part of day zero.

Why five days? According to Robert Amler, the dean of the School of Health Sciences and Practice at New York Medical College and a former CDC chief medical officer, the majority of people will stop shedding the virus after five days, assuming they don’t have moderate or severe illness.

In fact, “most of the contagious period, believe it or not, begins even before you have symptoms,” Amler said. But in many cases, we won’t know we’re contagious at that point if we’re not experiencing any noteworthy symptoms. Contact tracing studies have found that transmission is unlikely to occur more than five days after symptom onset, so that’s why we’re advised to follow that timeline now.

When your five-day isolation period is up...

After isolation for five days, if you no longer have symptoms or if your symptoms are noticeably improving, you are free to leave your house — but you should wear a mask around other people for another five days.

Though it’s widely believed that transmission is unlikely five days after the onset of symptoms, there’s a chance you could still be contagious — hence the mask rule. According to Horney, one study found that an average of 31% of transmission occurs after five days. During this second five-day window, you should definitely try to avoid older people and immunocompromised individuals who are at risk, Amler stressed.

If you are still symptomatic or if you have a fever after the first five days, you should continue isolating at home until your symptoms improve or subside. Boden-Albala said a fever is a good indicator that you’re still fighting the virus. By contrast, it’s common for some other symptoms, like cough and congestion, to linger even after you’ve recovered. So as long as your symptoms are improving and you’re fever-free, you are good to go (again, with a well-fitted mask for another five days!).

“Even though chances are low that you could shed virus, they still exist,” Boden-Albala said.

The same rules apply regardless of your vaccination status. Being vaccinated will likely keep the disease milder, help you recover faster and keep you out of the hospital. Still, if you’re sick, you’re sick. Even breakthrough infections can be contagious.

If you feel better before five days are up...

Health officials are currently advising all people who test positive to isolate for five days, even if a) they are asymptomatic, b) they feel better sooner or c) they test negative via a rapid test before the end of their five-day isolation.

Rapid tests can be a great indicator of whether a person is contagious, but many doctors don’t recommend using them to test out of your five-day isolation period early. “Antigen tests aren’t really that accurate if you don’t have symptoms, and we’re also having a shortage of them,” Horney said.

Though false positives are very unlikely, false negatives do occur and could provide a misleading sense of security. Though it’s not required ― mainly since rapid tests are hard to come by ― you could use a rapid test twice after your five-day isolation period is up, Amler said. Testing twice increases the chance of accurately detecting the virus if you’re still contagious.

Public health experts don’t recommend taking a PCR test to determine whether you have recovered. Those tests are so sensitive, they can pick up on non-infectious bits of virus for up to 90 days after the infection. “This doesn’t mean you are infectious and shedding virus, but it does mean you will test positive on PCR,” Boden-Albala said.

If you had COVID and isolated for five days, but now someone in your household tests positive...

If you just had COVID-19 and isolated for five days, and then someone in your household tests positive and has to start isolating, that does not extend your isolation period or throw you into a new quarantine.

Per the CDC guidance, anyone who has tested positive for COVID within 90 days does not need to quarantine after a close contact (which is defined as being within 6 feet of someone who has COVID for at least 15 minutes). “You’ve developed an immunity and that immunity will last for some time,” Boden-Albala said.

Keep in mind, however, that natural immunity will eventually wane, and re-infections can occur. What happens a week or two after you recover does not necessarily apply to infections that occur a few months down the line.

According to Horney, the number one thing to do after you recover is to get your booster as soon you’re eligible. People who are vaccinated and boosted are not getting very sick.

“If you get boosted, you are much less likely to get severe disease or even have a breakthrough,” Boden-Albala said.

Dan Zeiler

Dan@zeiler.com

708-597-5900 x134

Dan Zeiler