What does a negative Covid19 antigen test result mean in asymptomatic persons?
With the many COVID-19 variants circling the globe today, many individuals flock to testing sites to be tested. Over 3 million COVID-19 tests were taken in the United States alone, as of March 7, 2021. That number is even higher today as the Delta variant and other variants persist. An antigen test, also known as the rapid antigen test, is the test that many individuals choose to use when they want results results quickly. However, many wonder about the COVID-19 antigen test accuracy, along with what negative and positive results mean.
Let’s discuss the rapid antigen test for Covid, what a negative or positive test means, and what to do when a test is positive.
What does a negative Covid19 antigen test result mean in asymptomatic persons?
A negative test result in an individual who is asymptomatic (showing no symptoms of COVID-19) means there is no current evidence that the individual tested as the COVID-19 virus, even if they have had recent or expected exposure to the virus. However, this could change quickly after the test is taken. An antigen test only presents a snapshot of the time that person was tested. A person who has possibly been exposed to COVID-19, but has no symptoms, could test positive a few days after their first negative test. These individuals should be tested 3-5 days after their first negative test.
Individuals who are unvaccinated who have had known exposure to COVID-19 but have not tested positive should continue to quarantine for 14 days. If a fully vaccinated person has been exposed to someone with suspected or confirmed COVID-19, they should get tested 3-5 days after exposure. They should continue to wear masks in public, indoor settings for 14 days or until they receive a negative test result from their second test. If a fully vaccinated person has tested positive or are starting to experience COVID-19 symptoms, they should self-quarantine.
When can a COVID19 test result in a false positive or false negative?
A false negative antigen test can happen when an individual has a low viral load. The viral load is the amount of the virus a person has during the time of testing. A person’s viral load may be low either at the very beginning of their infection or at the very end of it. One in five individuals with symptoms and a confirmed case of COVID-19 received a negative result from the antigen test, according to a study by the CDC. In a study by Cochrane, the antigen test correctly identified COVID-19 infections in only 72% of individuals with symptoms and 58% of people without symptoms. According to this study, the tests were most accurate when the individual was tested one week after symptoms first developed.
False positives have also been reported with the COVID-19 antigen test. False positives can happen in two ways: when the antigen test isn’t taken correctly or when the test is read before or after the specified time the results appear. False positives are less likely than false negatives to occur with antigen tests. In the same study by CoChrane, out of the individuals who did not have COVID-19, the antigen test correctly ruled out 95% of individuals with symptoms and 98.9% of people without symptoms.
What should be done if the COVID19 antigen test result is positive?
If a person tests positive for COVID-19 with an antigen test, that person should follow the CDC’s guidelines for isolation. This includes staying home until it’s safe to be around others and staying separate from others if living with others. Staying in a specific “sick room” and using a separate bathroom is preferred.
If a fully vaccinated person tests positive for the COVD-19 antigen test, a separate specimen might be collected and sent to a laboratory for testing and viral sequencing for public health purposes.
Get trusted COVID-19 test results with BioCollections
Although an antigen test might have a rapid answer, the polymerase chain reaction (PCR) test provides the most accurate and reliable test for detecting a COVID-19 infection. The PCR test detects the genetic material of the virus using a nasal swab. BioCollections can be your solution to put your mind at ease with safe, quick, and reliable COVID-19 testing. We offer PCR tests with accurate results and an accelerated turnaround time. Our test results can be ready within 11-13 hours.
Contact us with any questions, concerns, or if you need assistance connecting with any of our international or US-based testing locations.
