Many people who get sick with COVID may still test positive five days—and sometimes up to 10 days—after their symptoms begin, according to a new study published in JAMA Network Open. The research only fuels the ongoing discussion about how long people should isolate after they contract the virus, experts say.
For the study, researchers looked at data from more than 63,000 people who visited a community testing site in San Francisco from January 2021 to January 2022. The data spanned the pre-delta, delta, and omicron BA.1 periods. (BA.1 was the original omicron variant, first identified in November 2021.) The researchers found that, during the BA.1 surge, 80% of people (!!) had continued to test positive (via a rapid antigen test) five days after their symptoms had started.
And that’s a bit concerning. Currently, the Centers for Disease Control and Prevention (CDC) recommends isolating at home for “at least” five days if you test positive for COVID, even if you don’t have any symptoms. (FYI: The first day is technically the day after you test positive). At the five-day mark, you can end isolation if you test negative, if you don’t have symptoms, or if your symptoms are improving and you haven’t had a fever (without the use of fever-reducing meds) in 24 hours.
So…does that mean all those COVID-positive people in the study were also still contagious at the five-day mark? Unfortunately, there’s no way to know for sure, Thomas Russo, MD, an infectious disease expert at the University of Buffalo Jacobs School of Medicine and Biomedical Sciences, who was not involved with the new study, tells SELF. Remember, the coronavirus that causes COVID-19 is still considered to be relatively new—meaning there’s a lot that experts don’t know or totally understand about it yet. A positive test at the five-day mark confirms the presence of the virus, yes—but that doesn’t totally tell doctors how likely a person is to spread COVID at that point in time. “[Doctors are asking:] Is that just parts of dead virus, or are you truly infectious?” Dr. Russo posits.
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That said, we shouldn’t rule out the possibility that some people will potentially be infectious five days after they test positive for COVID, William Schaffner, MD, professor of medicine in the division of infectious diseases at Vanderbilt University Medical Center, who was not involved with the new study, tells SELF. “Positive tests don’t tell us that a virus is live, but we think a substantial number of those people have live virus,” Dr. Schaffner says. “It’s likely that a lot of those people are still able to spread the virus.”
In fact, the authors of the JAMA study note that some existing data suggest a person’s infectiousness may last for an average of eight days; sometimes, a person may remain contagious beyond 10 days, but that’s thought to be “less common.”
This, Dr. Schaffner explains, is why it may not be totally safe to give everyone the all-clear after they isolate for just five days at home: “If you were going to visit your grandparents or a relative who had diabetes or heart disease and you had COVID, I would wait longer before I visited those high-risk people.”
So, how long should you isolate after a positive COVID test?
It’s frustrating, but many people probably won’t isolate longer than five days after getting sick with COVID—if they even bother to wait that long, Dr. Schaffner says. Pandemic fatigue is real, and many people are eager to return to their pre-COVID lives, he adds. Of course, some people simply don’t have the option to stay home from work that long.
Source: SELF