Fresno County health officials on Wednesday warned the public that rapid COVID-19 tests can provide misleading results.
Their assessment of over-the-counter tests comes amid a surge of Omicron cases in the county impacting hospitals and the re-opening of schools.
Rick Lembo, director of sports medicine at Sierra Pacific Orthopedic who works closely with Fresno State athletics, and Fresno County’s Dr. Rais Vohra say they know of inaccurate rapid test results.
“In some ways, they’re not really even answering the question, do I have COVID?” said Vohra, the county’s interim health officer. “They’re answering the question, am I contagious?”
Rapid Tests Can Give Contradictory Results
Vohra says asymptomatic individuals may not always test positive for COVID as opposed to a person who is clearly showing COVID symptoms.
“We know that although asymptomatic infections are out there, that it’s really the contagious folks who are symptomatic who we really have to focus our attention on during this time of surge,” said Vohra.
After conducting several thousand tests in the last two months, Lembo says that vaccinated and boosted individuals don’t always test positive when their symptoms are at their worst.
They will swab negative for three or four days and on the fifth day, when they are finally feeling better, they will test positive,” Lembo said.
“So, it looks like the vaccines and the boosters are quelling the viral load, they’re quelling the symptoms,” said Lembo. “And, after three or four days, you have enough to test positive, but you’re actually on the downslope of being sick and feeling better.”
Follow the Directions ‘Meticulously’
On Monday, The New York Times reported that “some of the at-home rapid antigen tests have an overall sensitivity of roughly 85 percent, which means that they are … missing 15 percent. In some studies, their real-world performance has been even lower.”
Dr. Patrick Godbey, a former president of the College of American Pathologists, told The Times: “If you’re doing at-home tests, you must read the instructions and follow them meticulously.”
Experts say that polymerase chain reaction tests (PCR) are the most accurate at detecting COVID-19. Those tests are typically performed in a laboratory and can detect minute traces of the virus.
Positive COVID Cases Likely Are Underreported
Apart from the sometimes unreliable results, the rapid tests are going up in price, hard to find, and have no record of data to follow if individuals don’t report being positive.
According to the county’s health department manager, Joe Prado, PCR test results are the only positive cases reported on the state vaccine dashboard — meaning there could be thousands more who test positive for COVID and don’t report their status.
“We really rely on communication with our public about if you are positive, we want to make sure you give us a call on our COVID information line,” said Prado. “For now, we just don’t know how many of those other over-the-counter type of rapid test kits, what the uptake has been, and what those results have been.”
If you purchase a test kit from a pharmacy and test positive, you should report it to the health department’s COVID information line, Prado said. The results will then be entered into the state database.
Schools Take Added Precautions
This week, the Fresno County Superintendent of Schools announced it was sending at-home test kits to 165,000 students starting this Friday right before school resumes.
Meanwhile, Fresno State said on Wednesday classes will be online only, at least for the month of January, because of the COVID-19 surge.
Fresno State athletics have also seen some disruption with games being postponed because of COVID.
“It’s not surprising at all that sports might be disrupted, postponed, delayed or, you know, adjustments need to be made related to athletic activities,” said Vohra. “But, we have full faith in Fresno State and really all of the colleges that we work with, that they have safety protocols in place.”
Testing and Vaccination Sites
To report positive COVID test results, call the COVID information line at (888) 559-2683
For a full schedule of testing events and sites, click here.