The United States is currently in the midst of an outbreak of the new coronavirus. JN.1 variant That's driving up hospitalizations and deaths across the country. But for most people, the new variant does not seem to cause worsening of symptoms.
That's why many people are wondering whether they should keep swabbing their nasal passages for coronavirus tests at the first sign of nasal congestion or pain. How well do rapid at-home tests work against new variants?
Here's what you need to know:
Do I still need to take a Covid test?
Influenza and some cold viruses are also circulating along with the new coronavirus. So there is good reason to know which virus you have, especially if you are at high risk of becoming seriously ill.
“It's important to know whether you have COVID-19, influenza, or a completely non-viral infection such as strep throat,” said Dr. Abrar Karan, an infectious disease physician at Stanford University. Because they have different treatments.” “There are different treatments for each, and the sooner you receive treatment, the better the results.”
If you're a healthy 25-year-old, there’s still some value in getting tested. For example, if you have someone in your household with a weakened immune system or someone who is battling cancer, it is important to isolate them to see if they have COVID-19.
“Remember that all of these viral and bacterial infections are transmissible differently and get sick differently,” Curran said.
Joseph Petrosino, a professor of molecular biology and microbiology at Baylor College of Medicine, said while there may not be much need for young, healthy people to get tested at home, they should be tested for the coronavirus just in case. He acknowledged that it might be helpful to know. Eventually, the symptoms will persist.
“Some people, even healthy people, runners and people who train, can get a prolonged COVID-19 infection,” he said. “We really don't know. It's difficult to predict based solely on comorbidity factors.”
Otherwise, for people at low risk, a positive coronavirus test does not change treatment much. Whether you have coronavirus, a cold or the flu, get plenty of rest, stay hydrated, and stay away from others.
How will new variants impact testing?
Experts say there is no data showing the JN.1 variant affects the results of rapid home tests.
“We have not seen anything to suggest that the new variant has evaded test detection,” Curran said. “Certainly, similar things have happened in the past with other diagnostics early in the pandemic, but right now tests should be able to detect these mutations.”
Susan Butler Wu, a clinical pathologist at the Keck School of Medicine at the University of Southern California, said she hasn't seen any data on this particular variant, but if it's similar to other variants, it’s not a problem. Rapid tests actually look for parts of the virus that are less likely to mutate and bypass testing.
“There's always the fear that a mutation will occur and the test won't work, but so far that hasn't really happened,” Butler-Wu said.
When is the best time to test?
An individual's viral load is highest early in a pandemic, when most people first develop symptoms, either after infection or before they have developed any immunity from vaccines.
Now, one researcher says that virus levels may actually be at their highest in the first few days of illness. study It was published last fall in the journal Clinical Infectious Diseases by researchers at Harvard Medical School. They found that in people with pre-existing immunity, virus levels peaked around the fourth day after symptoms appeared.
This means that if you are tested in the early stages of the disease, it may turn out to be negative.
“Their symptoms may be caused by an immune response,” Curran said. “That means there's inflammation going on, which is causing the symptoms, and that's preventing the virus from multiplying as quickly. That's why the initial test could be negative.”
The U.S. Centers for Disease Control and Prevention still recommends getting tested immediately if you think you have been infected with the coronavirus and have symptoms such as a stuffy nose, cough, or body aches.
The CDC says to wait five days if you are infected but have no symptoms.
Butler-Wu says there is a misconception that rapid tests are “one-and-done”.
“If you have symptoms and your first test was negative, you should test again,” she says.
Official guidance from the CDC is to get a rapid test if you have symptoms and then test again 48 hours later if you test negative.
The test result was positive. Does that mean I'm contagious?
A rapid at-home test is a good way to find out if someone is contagious.
Simply put, rapid tests require higher levels of virus to be positive, and higher virus levels usually mean you're more contagious.
However, the test has some limitations.
Curran said they can be a good surrogate for contagiousness in the early stages of the disease, but are not as reliable at the end of the disease.
Rapid tests have shown positive results, but data shows the virus could not be cultured when samples were taken from people. That means those people are less likely to be contagious, Curran said.
2022 study Researchers at Harvard Medical School suggested that only half of people who test positive after five days are actually infectious.
“Even after that period, even if you test positive on a rapid test, there is no guarantee that you are still contagious.”
