What does a negative COVID-19 test result mean?

Tabla de contenidos:

1. What does a negative COVID-19 test result mean?
2. What is the COVID-19 PCR diagnostic test?
3. Is the PCR test for COVID-19 accurate?
4. What are the types of COVID-19 tests?
5. Are COVID-19 molecular tests more accurate than antigen tests?
6. Are saliva tests just as effective as nasal swabs to diagnose COVID-19?
7. Which is more accurate nasopharyngeal or nasal swab for COVID-19 testing?
8. Can someone test negative and later test positive on a viral test for COVID-19?
9. Does a negative result rule out the possibility of COVID-19?
10. How accurate are rapid COVID-19 antigen tests?
11. Can COVID-19 antigen tests be false positive?
12. Have saliva tests been approved by FDA as a sample for the coronavirus disease testing?
13. Can a self-collected saliva sample detect COVID-19?
14. How is the COVID-19 nasal swab test performed?
15. Does a negative result for COVID-19 test mean I don't have the virus?
16. What are consequences of a false negative COVID-19 test?
17. How long does it take for symptoms of the coronavirus disease to appear?
18. What are the factors that can determine transmission risk of COVID-19?
19. Can asymptomatic people transmit COVID-19?
20. Has COVID-19 been detected in drinking water supplies?

What does a negative COVID-19 test result mean?

A negative test result for this test means that SARS- CoV-2 RNA was not present in the specimen or the RNA concentration was below the limit of detection. 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 is the COVID-19 PCR diagnostic test?

PCR test: Stands for polymerase chain reaction test. This is a diagnostic test that determines if you are infected by analyzing a sample to see if it contains genetic material from the virus.

Is the PCR test for COVID-19 accurate?

PCR tests remain the gold standard for detecting an active COVID-19 infection. The tests have accurately detected COVID-19 cases since the pandemic began. Highly trained clinical professionals are skilled at correctly interpreting PCR test results and notices like this one from the WHO.

What are the types of COVID-19 tests?

There are two different types of tests – diagnostic tests and antibody tests.

Are COVID-19 molecular tests more accurate than antigen tests?

Molecular tests are generally more accurate and mostly processed in a laboratory, which takes longer; antigen tests—which are sometimes referred to as 'rapid tests'—are processed pretty much anywhere, including in doctor's office, pharmacies, or even at home.

Are saliva tests just as effective as nasal swabs to diagnose COVID-19?

Saliva testing for coronavirus disease 2019 (COVID-19) is as effective as the standard nasopharyngeal tests, according to a new study by investigators at McGill University.

Which is more accurate nasopharyngeal or nasal swab for COVID-19 testing?

In other words, you are more likely to obtain a more accurate diagnosis when sampling with the nasopharyngeal (NP) swabs than you are with a nasal or throat swab.” For this reason, the nasopharyngeal swab has been the standard for reliable testing.

Can someone test negative and later test positive on a viral test for COVID-19?

Yes, it is possible. You may test negative if the sample was collected early in your infection and test positive later during this illness. You could also be exposed to COVID-19 after the test and get infected then. Even if you test negative, you still should take steps to protect yourself and others. See Testing for Current Infection for more information.

Does a negative result rule out the possibility of COVID-19?

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

How accurate are rapid COVID-19 antigen tests?

Rapid antigen tests are very specific for the coronavirus. A positive result likely means that you are infected. However, rapid antigen tests are not as sensitive as other tests, so there is a higher chance of a false negative result.

Can COVID-19 antigen tests be false positive?

Despite the high specificity of antigen tests, false positive results will occur, especially when used in communities where the prevalence of infection is low – a circumstance that is true for all in vitro diagnostic tests.

Have saliva tests been approved by FDA as a sample for the coronavirus disease testing?

This is the fifth test that the FDA has authorized that uses saliva as a sample for testing. Testing saliva eliminates the need for nasopharyngeal swabs, which have also been prone to shortages, and alleviates the patient discomfort associated with these swabs. Since the saliva sample is self-collected under the observation of a healthcare professional, it could also potentially lower the risk posed to healthcare workers responsible for sample collection.

Can a self-collected saliva sample detect COVID-19?

A self-collected saliva sample is as good at detecting COVID-19 as a nasal swab administered by a health care worker -- without exposing medical staff to the virus while collecting the sample.

How is the COVID-19 nasal swab test performed?

A fluid sample is collected by inserting a long nasal swab (nasopharyngeal swab) into your nostril and taking fluid from the back of your nose or by using a shorter nasal swab (mid-turbinate swab) to get a sample.

Does a negative result for COVID-19 test mean I don't have the virus?

You can test negative for COVID-19 and still have it. A nasal swab test is merely a snapshot in time. In other words, receiving a negative COVID-19 test result today doesn't mean you definitely don't have the virus, but rather that there wasn't enough virus collected to register as a positive at the time of your test.

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

Risks to a patient of a false negative test result include: delayed or lack of supportive treatment, lack of monitoring of infected individuals and their household or other close contacts for symptoms resulting in increased risk of spread of COVID-19 within the community, or other unintended adverse events.

How long does it take for symptoms of the coronavirus disease to appear?

On average it takes 5–6 days from when someone is infected with the virus for symptoms to show, however it can take up to 14 days.

What are the factors that can determine transmission risk of COVID-19?

Factors that determine transmission risk include whether a virus is still replication-competent, whether the patient has symptoms, such as a cough, which can spread infectious droplets, and the behavior and environmental factors associated with the infected individual.

Can asymptomatic people transmit COVID-19?

Yes, infected people can transmit the virus both when they have symptoms and when they don't have symptoms. This is why it is important that all people who are infected are identified by testing, isolated, and, depending on the severity of their disease, receive medical care.

Has COVID-19 been detected in drinking water supplies?

The COVID-19 virus has not been detected in drinking-water supplies, and based on current evidence, the risk to water supplies is low.