Have you or your children recently experienced a spate of symptoms you were sure indicated Covid-19, only to test negative? You aren’t alone, and some families are wondering if perhaps a new variant is spreading that just isn’t showing up on the tests.
Here’s what we know.
How Common Are False-Negatives?
Most medical tests have at least a small risk of false negative or false positive results (just ask any woman who has ever had a pregnancy test show them an incorrect result). But what is the actual risk of testing negative while still having Covid-19?
“It depends on the type of test (antigen vs PCR), and the stage of carriage/infection,” internationally recognized leader in pediatric and infectious disease care and research Gerald W. Fischer, MD, explained.
“If the virus is in the early stage of replication, false negative antigen tests can occur,” he said. “A study published by the CDC found that the antigen test provided a 20 percent false negative rate in symptomatic individuals and 59 percent false negative rate in asymptomatic persons.”
That’s a significantly high rate of false negatives, which means it’s certainly possible to be Covid-positive but to test negative. But there are more accurate tests available.
“Highly sensitive PCR testing significantly reduces false negatives,” Fischer said. And reducing that risk is important.
“As oral antivirals for Covid get closer to approval, it is crucial to minimize false negative results for both symptomatic and asymptomatic individuals,” Fischer explained. “Merck’s new antiviral Molnupiravir blocks the virus from replicating. The earlier the virus is detected the more effective it will be in reducing both disease and spread.”
Could a New Variant Be Evading Tests?
We’ve all heard about new variants spreading, so it’s fair to wonder if there might be a new variant tricking Covid-19 tests more than ever before.
The good news is: that doesn’t appear to be the case.
“There is no current evidence that a new variant is spreading that is not detectable by FDA authorized tests,” Fischer said. “Molecular surveillance, including next generation sequencing, continues to monitor changes to the virus to ensure that current tests remain accurate.”
In other words: if there were a new variant getting past the current tests, we would probably know by now.
So What’s With the Increase in Covid-19 Symptoms?
After the last two years of pandemic panic, it makes sense that people might automatically assume they have Covid-19 at the presentation of any Covid-like symptoms. What we have to remember is that other viruses existed prior to Covid-19, and continue to spread today.
“With the opening of schools and more people going back to the office, Covid-like symptoms are certainly rising,” Fischer said. “My own teenage granddaughters just recently both had Covid-19 symptoms with sore throats, elevated temperatures, and congestion and they both tested negative for COVID by both antigen and PCR testing.”
Family practitioner Janice Johnston, MD, is seeing this in her practice first-hand.
“Other common illness can definitely overlap Covid-19 symptoms,” she explained. “Influenza, or the flu, shares many symptoms such as body aches, fever, chills, cough, headache, and congestion.”
She suggested testing for the flu if you have Covid-symptoms but have tested negative for Covid-19.
“With more people moving about this year, we do expect influenza to be prevalent this season,” she explained.
But it’s not just the flu that could be causing your symptoms.
“Covid-like symptoms can be caused by a wide variety of viruses and bacteria, to include influenza, RSV, adenovirus, and group A strep,” Fischer said. “If an individual has an illness caused by one of these common pathogens, it would be expected they would test negative for Covid.”
So Let’s Say it’s Not Covid
Just because you or your child tests negative for Covid-19 does not mean your symptoms don’t matter.
“If someone does not feel well, it is definitely advised to stay home until a fever has resolved and the individual feels better,” Johnston said. “I recommend seeing or speaking to your doctor for possible testing, treatments, and prescriptions that could help.”
With all illnesses, she said it is important to help your body heal by getting plenty or rest and fluids. You can also control symptoms with Tylenol or Ibuprofen, as well as taking vitamins to boost your immune system. Vitamin C and Zinc are good options, she said.
“If you are asthmatic or have COPD, make sure you are taking your preventative medications and have your rescue inhalers on-hand,” Johnston said.
Fischer agreed, adding that it is always a good idea to call your child’s pediatrician if they are sick.
“Pediatricians have a good sense of what viruses are currently spreading in the community,” he explained. “If necessary, the pediatrician can test for a wider range of pathogens such as influenza which can be treated.”
And the most important thing you can do, according to Fischer? Stay up to date on all vaccinations, not just Covid-19.
“While it is crucial to continue to vaccinate and boost against COVID, individuals should ensure they are current on their vaccinations against other pathogens such as influenza and pneumococcus,” he explained. “Both pathogens can cause severe illness on their own and would likely be worse if co-infected with Covid.”
So stay hydrated and vaccinated and pay attention to any symptoms you or your children may be exhibiting, regardless of whether you test negative for Covid-19 or not.