ZME Science
No Result
View All Result
ZME Science
No Result
View All Result
ZME Science

Home → Science

Our COVID-19 tests are still imperfect, study notes, cautioning against false negatives

Even with very effective tests, we'll still see false positives.

Alexandru MicubyAlexandru Micu
April 10, 2020
in Health, News, Science
A A
Share on FacebookShare on TwitterSubmit to Reddit

False-negative tests could pit us against a “less visible second wave of infection,” according to the authors of a new study published in Mayo Clinic Proceedings.

Image via Pxhere.

As our ability to screen for COVID-19 increases, medical personnel and health officials have to keep in mind that tests aren’t perfect, and that false results can have an effect on our ability to contain the pandemic. The sensitivity of reverse transcriptase-polymerase chain reaction (RT-PCR) testing, our main way of identifying infected patients, has not been clearly or consistently reported in the literature, but even at high accuracy rates, large numbers of false-negative results are likely.

“RT-PCR testing is most useful when it is positive,” says Dr. Sampathkumar, an infectious diseases specialist at Mayo Clinic and a study co-author.

“It is less useful in ruling out COVID-19. A negative test often does not mean the person does not have the disease, and test results need to be considered in the context of patient characteristics and exposure.”

In broad lines, such tests can be used to detect the presence of the virus in a patient by copying all the DNA in a sample of their blood, multiplying everything, and then looking for bits of viral DNA. Unlike tests that look for antibodies in the blood, RT-PCR can detect the virus even before our bodies have begun to respond to it, which is an important ability. On the downside, they are less reliable, as a negative result simply means there was no viral DNA found in that sample; it could, theoretically, still be somewhere else in the body.

Even with sensitivity values as high as 90% (this value determines the test’s ability to detect the virus in an infected sample), the team argues we’d see a substantial number of false-positives. Such patients are still able to pass the virus on, even if they’re asymptomatic.

“In California, estimates say the rate of COVID-19 infection may exceed 50% by mid-May 2020,” Dr Sampathkumar says.

“With a population of 40 million people, 2 million false-negative results would be expected in California with comprehensive testing. Even if only 1% of the population was tested, 20,000 false-negative results would be expected.”

Healthcare personnel are one of the most exposed groups in this pandemic. If even just 10% of all those involved in providing direct patient care in the US got infected, although this is far below current predictions the team explains, we could be looking at over 40,000 false-negatives in this field alone.

Given that current guidelines from the Centers for Disease Control and Prevention (CDC) call for asymptomatic health care workers who tested negative for the virus to return to clinical care, this could help spread the disease even more rapidly inside hospitals, according to the team.

The authors recommend continued strict adherence to physical distancing, hand-washing, surface disinfection, and other preventive measures for everyone, while working on the “development of highly sensitive tests or combinations of tests” to allow us to confidently tell sick and healthy individuals apart.

RelatedPosts

Faced with a resurgence of coronavirus cases, Berlin institutes new, tough restrictions
UK fails to report on positive COVID-19 cases due to glitch
A coronavirus recovery can benefit biodiversity, researchers argue
Masks and gloves won’t keep you from getting infected — save them for the doctors

The paper “COVID-19 Testing: The Threat of False-Negative Results” has been published in the journal pre-proof Mayo Clinic Proceedings.

Tags: coronavirusCOVID-19testsvirus

ShareTweetShare
Alexandru Micu

Alexandru Micu

Stunningly charming pun connoisseur, I have been fascinated by the world around me since I first laid eyes on it. Always curious, I'm just having a little fun with some very serious science.

Related Posts

Health

Herpes Virus Hijacks Human DNA Within Just an Hour of Infection

byTudor Tarita
7 days ago
Diseases

That 2022 Hepatitis Outbreak in Kids? It Was Apparently COVID

byMihai Andrei
3 months ago
Genetics

Finally, mRNA vaccines against cancer are starting to become a reality

byMihai Andrei
4 months ago
Biology

Scientists Uncover Bizarre Virus-Like Structures in the Human Body and We Have No Idea What They Are

byMihai Andrei
4 months ago

Recent news

Buried in a Pot, Preserved by Time: Ancient Egyptian Skeleton Yields First Full Genome

July 3, 2025

AI Helped Decode a 3,000-Year-Old Babylonian Hymn That Describes a City More Welcoming Than You’d Expect

July 3, 2025

Peeling Tape Creates Microlightning Strong Enough To Power Chemistry

July 3, 2025
  • About
  • Advertise
  • Editorial Policy
  • Privacy Policy and Terms of Use
  • How we review products
  • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.

No Result
View All Result
  • Science News
  • Environment
  • Health
  • Space
  • Future
  • Features
    • Natural Sciences
    • Physics
      • Matter and Energy
      • Quantum Mechanics
      • Thermodynamics
    • Chemistry
      • Periodic Table
      • Applied Chemistry
      • Materials
      • Physical Chemistry
    • Biology
      • Anatomy
      • Biochemistry
      • Ecology
      • Genetics
      • Microbiology
      • Plants and Fungi
    • Geology and Paleontology
      • Planet Earth
      • Earth Dynamics
      • Rocks and Minerals
      • Volcanoes
      • Dinosaurs
      • Fossils
    • Animals
      • Mammals
      • Birds
      • Fish
      • Amphibians
      • Reptiles
      • Invertebrates
      • Pets
      • Conservation
      • Animal facts
    • Climate and Weather
      • Climate change
      • Weather and atmosphere
    • Health
      • Drugs
      • Diseases and Conditions
      • Human Body
      • Mind and Brain
      • Food and Nutrition
      • Wellness
    • History and Humanities
      • Anthropology
      • Archaeology
      • History
      • Economics
      • People
      • Sociology
    • Space & Astronomy
      • The Solar System
      • Sun
      • The Moon
      • Planets
      • Asteroids, meteors & comets
      • Astronomy
      • Astrophysics
      • Cosmology
      • Exoplanets & Alien Life
      • Spaceflight and Exploration
    • Technology
      • Computer Science & IT
      • Engineering
      • Inventions
      • Sustainability
      • Renewable Energy
      • Green Living
    • Culture
    • Resources
  • Videos
  • Reviews
  • About Us
    • About
    • The Team
    • Advertise
    • Contribute
    • Editorial policy
    • Privacy Policy
    • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.