When one of the two targets (but not both) is above the positive threshold, the test reports « indeterminate ». This is usually seen in small amounts of viral DNA. In practice, an « inconclusive » result should be considered a presumptive positive COVID case with a low viral load.

What does a negative COVID-19 test result mean?

A negative test result for this test means that SARS-CoV-2 RNA is not present in the sample or that the RNA concentration is below the detection limit. However, a negative result does not rule out COVID-19 and should not be used as the sole basis for treatment or patient management decisions.

What are the consequences of a false negative COVID-19 test?

Risks to patients from false-negative test results include: delayed or lack of supportive care, lack of symptomatic surveillance of infected individuals and their family members or other close contacts leading to increased risk of community transmission of COVID-19, or other unexpected adverse events.

What does it mean if I test positive for COVID-19?

If you test positive, you most likely have COVID-19 because proteins from the virus that causes COVID-19 were found in your sample. Therefore, you may also be quarantined to avoid spreading the virus to others. There is a small chance that this test will give a false positive result (false positive result). Your healthcare provider will work with you to determine how best to care for you based on your test results and your medical history and symptoms.

What is the false positive rate for virus testing?

The false-positive rate—the frequency with which a test says you have the virus when you actually don’t—should be close to zero. Most false-positive results are thought to be due to laboratory contamination or other problems with how the laboratory conducts the test, rather than limitations of the test itself.

Interpreting test results for COVID-19

35 related questions found

Can a COVID-19 antigen test give false positives?

The U.S. Food and Drug Administration (FDA) is reminding clinical laboratory workers and healthcare providers of the potential for false-positive results from antigen tests, including when users do not follow instructions for using antigen tests to rapidly test for SARS-CoV-2 .

How accurate is the COVID-19 PCR test?

PCR tests are very accurate when performed correctly by a healthcare professional, but some conditions can be missed by the rapid test.

How long can you remain infectious after testing positive for COVID-19?

If someone is asymptomatic or their symptoms disappear, it is possible to remain infectious for at least 10 days after testing positive for COVID-19. People hospitalized with serious illness and people with weakened immune systems can be contagious for 20 days or more.

Do I need to isolate for COVID-19 after a positive screening test?

If a person tests positive for a screening test and is referred for a confirmatory test, they should isolate until they receive the results of the confirmatory test. For guidance on isolation and testing for fully vaccinated individuals, visit Temporary public health advice for fully vaccinated individuals.

How long should I isolate after testing positive for COVID-19?

If you still have no symptoms, you can be with other people 10 days after you test positive for COVID-19.

Does a negative result rule out COVID-19?

A negative result does not exclude COVID-19 and should not be used as the sole basis for treatment or patient management decisions. A negative result does not rule out COVID-19.

Do I need to show a negative COVID-19 test result when entering the United States?

All air passengers traveling to the U.S., including U.S. citizens and fully vaccinated individuals, must have a negative COVID-19 test no more than 3 days prior to travel, or documentation of recovery from COVID-19 within the past 3 months Board a flight to the United States.

Should I delay travel if I feel unwell despite testing negative for COVID-19?

If you test negative for COVID-19 and you are still sick, postpone your travel until you recover – other infectious diseases can also be spread through travel.

What should a symptomatic person who receives a negative COVID-19 antigen test result do?

Symptomatic individuals who receive a negative antigen test result and then NAAT confirms a negative result but have been in close contact with a COVID-19 patient in the past 14 days should follow CDC isolation guidance, which may include Re-detect the last known exposure days later.

When do people with COVID-19 become contagious?

Researchers estimate that people infected with the coronavirus can spread it to others 2 to 3 days before symptoms start, and are most contagious 1 to 2 days before they feel sick.

What should I do after getting my COVID-19 test results?

• If you test positive, learn about protective measures to prevent others from getting sick.
• If your test result is negative, you may not have been infected when the sample was collected. A test result simply means that you did not have COVID-19 at the time of the test. Continue to take steps to protect yourself.

What is the protocol when an employee tests positive for COVID-19?

If an employee is confirmed to have COVID-19, employers should inform colleagues that they may have been exposed to COVID-19 in the workplace, subject to confidentiality as required by the Americans with Disabilities Act (ADA). People with symptoms should self-isolate and follow the steps recommended by the CDC.

Can children still go to school if a parent tests positive for COVID-19?

If you or anyone in your household tests positive, your child should follow the school’s isolation guidance. If your child also tests positive, they should not go to school even if they are not showing symptoms. They should follow the school’s quarantine guidance.

When can I be with other people after having mild or moderate COVID-19?

You can be with other people when:
• 10 days after symptoms first appeared, and.
• No fever for 24 hours and no fever reducers.
• Other symptoms of COVID-19 are improving*

Can a recovered person who tests persistently positive for COVID-19 infect others?

In some cases, people who have consistently or repeatedly tested positive for SARS-CoV-2 RNA have improved signs and symptoms of COVID-19. When virus isolation in tissue culture was attempted in these individuals in Korea and the United States, no live virus has been isolated. To date, there is no evidence that clinically recovered individuals with persistent or repeated detection of viral RNA have transmitted SARS-CoV-2 to others.

Despite these observations, it is impossible to conclude that all individuals with persistent or repeated detection of SARS-CoV-2 RNA are no longer infectious. There is no conclusive evidence that antibodies against SARS-CoV-2 infection are protective. If these antibodies are protective, it is unclear what antibody levels are needed to prevent reinfection.

Are at-home COVID-19 test kits accurate?

These tests are generally less reliable than traditional PCR tests, but they are still relatively accurate and provide faster results.

How accurate is the COVID-19 test at home?

Clinical studies of the Ellume COVID-19 home test have shown that it is 96 percent accurate for those with symptoms and 91 percent for those without symptoms. Finally, according to a clinical study, Quidel QuickVue touts an 83 percent accuracy rate for detecting positive cases and 99 percent accuracy for detecting negative cases.

Can a molecular test for COVID-19 give false negatives?

Molecular tests are usually highly sensitive to detect the SARS-CoV-2 virus. However, false-negative results are possible with all diagnostic tests, and the risk of false-negative results may increase when testing patients with SARS-CoV-2 genetic variants.

How accurate is the rapid COVID-19 antigen test?

Rapid antigen tests are very specific for coronaviruses. A positive result could mean you have been infected. However, rapid antigen tests are not as sensitive as other tests, so there is a higher chance of false-negative results.

What is a rapid antigen test for COVID-19?

Two types of rapid tests are used to detect active COVID-19 infection: rapid antigen tests that use paper strips to detect viral proteins and rapid molecular tests (including PCR) that use medical devices to detect the genetic material of the virus.