by The US is currently in the midst of a Covid wave, fueled by the JN.1 variant that is causing hospitalizations and deaths across the country. For most people, however, the new variant doesn’t seem to be causing any worse symptoms.
That has left many wondering if we need to keep swabbing our nasal passages with Covid tests at the first sign of congestion or pain? How well do quick tests at home work against the new version?
Here’s what you need to know:
Do I still need a Covid test?
Flu and some cold viruses are spreading along with Covid. So there are good reasons to know what virus you have, especially if you are at increased risk of illness.
“It’s important to know if you have Covid versus the flu versus something that’s not viral at all – like strep throat – because they have different treatments,” said Dr. Abraar Karan, a disease doctor constructs at Stanford Medicine. “They have different treatments, and the sooner you get treatment, the better the outcome.”
For a healthy 25-year-old, some utility remains to be tested. If someone at home has a weak immune system or is fighting cancer, for example, isolation is important if it’s Covid.
“Remember with all these viruses or bacterial infections, the infection is different and how sick you can get is different.” Karan said.
Joseph Petrosino, chair of molecular biology and microbiology at Baylor College of Medicine, acknowledged that while it may not be as necessary for young, healthy people to get tested at home, it can be helpful to know is there covid just in case. ends up with lingering symptoms.
“There are healthy people, runners or people who are working out, who get Covid too long,” he said. “You never really know—it’s hard to predict based on comorbidity factors alone.”
Otherwise, for someone who is at low risk, getting a positive Covid test won’t make a big difference in treatment. Whether it’s Covid, cold or flu, get plenty of rest, stay hydrated and stay away from others.
How does the new version affect testing?
There is no data that the JN.1 version should have any effect on rapid test results at home, experts say.
“I haven’t seen anything to suggest that the newer versions have evaded detection on tests,” Karan said. “Certainly this has happened in the past with other diagnostics earlier in the pandemic, but at this point the tests should pick up these variants.”
Susan Butler-Wu, a clinical pathologist at the Keck School of Medicine at the University of Southern California, said while she hasn’t seen data for this specific variant, if it’s similar to other variants, it won’t be an issue. In fact, rapid tests look for a part of the virus that is less likely to mutate and evade the tests.
“There’s always this fear that we’re going to have some mutation that makes the tests not work now, but so far that’s not really the case,” Butler-Wu said.
When is the best time to test?
In the early days of the pandemic, before most people had some form of immunity after infection or from vaccines, a person’s viral load would have been higher when symptoms first appeared.
Now, levels of the virus may actually be higher a few days into the illness, according to a study published last fall in the journal Clinical Infectious Diseases by researchers at Harvard Medical School. They found that the level of the virus rises around the fourth day of symptoms in those people who already have immunity.
This means that if someone tests too early in the illness, it could be negative.
“Their symptoms could be a result of their immune response,” Karan said. “So you’re getting inflammation and that’s causing the symptoms, and that’s preventing the virus from multiplying as quickly, so your initial test could be negative.”
The Centers for Disease Control and Prevention still recommends testing immediately if you believe you have been exposed to Covid and are showing symptoms such as congestion, coughing or body aches.
If you’ve been exposed but have no symptoms, the CDC says it will wait five days.
There’s a misconception that rapid tests are “one and done,” says Butler-Wu.
“If you have a symptom and the first one is negative, you have to do it again,” she said.
The official guidance from the CDC is that if you have symptoms, do a quick test, and if it’s negative do it again 48 hours later.
I tested positive. Does that mean I’m contagious?
Quick home tests are a good way to find out if someone is contagious.
Simply put, rapid tests require a higher level of virus to be positive, and higher levels of virus usually mean someone is more contagious.
However, the tests have some limitations.
Karan said that while they can be good proxies for infectivity early in the course of the illness, they are less reliable late in the illness.
There are data where rapid tests were positive, but when they got people’s samples, the virus couldn’t be cultured — meaning those people were unlikely to be contagious, Karan said.
A 2022 study by researchers at Harvard Medical School suggested that only half of people who test positive after five days are actually contagious.
“After that time, if your rapid test is positive it’s not a guarantee that you’re still contagious.”
This article was originally published on NBCNews.com
