What are the different types of COVID-19 tests available?

Viral tests look for various portions of the SARS-CoV2 virus which causes COVID-19. Most tests are either antigen or PCR tests.

A COVID-19 viral test is used to detect the presence of virus in a patient’s nose, mouth, or throat. There are two types of viral tests:

• Antigen test – detects specific proteins on the surface of the virus. Many antigen tests can be performed at the point-of-care with results available within 15 minutes. 
• PCR test – a molecular test that detects the virus’s genetic material. PCR tests usually have a higher level of accuracy but often need to be sent to the lab for processing.

Since the criteria to get tested are evolving, we recommend that you visit the CDC testing page to gain better understanding of your need to get a COVID-19 viral test. If you do need testing, it is important to remember that there is no benefit to being tested immediately after exposure as the test will not turn positive immediately. It is ideal to wait at least 3-5 days before getting tested.

Close contact is defined as being within six feet of a person with COVID-19 for more than a total of 15 minutes in any 24-hour period.

• Symptomatic individuals: If you are experiencing symptoms you should be evaluated for active infection. Please visit a Summit Health Urgent Care or CityMD location for evaluation and possible testing.
• Asymptomatic individuals: If you have no symptoms, call your Summit Health provider and select prompt 2 between 8:30 a.m. and 5 p.m. to schedule an appointment to be tested.
• Due to limited capacity and the need to prioritize patients needing urgent medical attention, asymptomatic and mildly symptomatic patients (based on specific criteria), who are seeking a COVID-19 test at a Summit Health Urgent Care Center may be asked to return at a scheduled appointment time that can be made at check in. If we cannot accommodate you shortly after you arrive, you will be given a time to return in an effort to minimize your wait. Please do not call for an appointment ahead of time.
• Asymptomatic patients who do not have an established Summit Health provider may go to one of our CityMD sites for evaluation and testing.

After a brief evaluation by a provider, a sample is collected from the nose using a swab and then tested for presence of virus particles.

Rapid Viral Testing: Summit Health uses the Quidel Sofia and the BD Veritor COVID-19 viral antigen tests. According to the manufacturer’s data submitted to the FDA, the tests have a negative predictive value (chances that a negative test truly means virus is not present in the sample) of 98-100% and positive predictive value (chances that a positive test truly means virus is present in the sample) of 83-99%.

All platforms used by Summit Health and CityMD have emergency Use Authorization (EUA) from the FDA for use in detection of COVID-19 infection based on performance data submitted by the manufacturer.

Based on the clinical situation, a PCR test may be sent to the lab for confirmation of the results. 

PCR testing: At Summit Health we use our internal lab analyzers to perform PCR test. PCR tests are considered the gold standard for COVID-19 testing. The sensitivity and specificity of the results are in well above 90%. However, as noted, these tests take longer to produce results.

If you receive a positive test result, it means that COVID-19 virus particles were detected in your sample. It is likely that you have COVID-19 and you should self-isolate to avoid spreading the virus to others.

There is a very small chance that this test can give a positive result that is incorrect (a false positive result) for several reasons:

• You may have recovered from the illness but are still shedding particles from dead virus
• You may have an infection with a different coronavirus, such as the ones that cause common colds

Interpretation of test results and how to best care for yourself should be based on your test results along with your medical history and symptoms in partnership with your health care provider.

In general, if you have a positive test you should isolate for at least 10 days and discuss other management and infection control plans with your provider.

A negative test result means that the COVID-19 virus was not found in your sample and you most likely do not have an active infection.

There is a small chance this test can give a negative result that is incorrect (a false negative result) for several reasons:

• You may be carrying the virus, but it was not detected in your secretions yet. This is called being in the incubation period.
• The sample did not collect enough secretions to detect the virus.

Your test result, together with all other aspects of your medical history and symptoms, should be used in deciding how to care for yourself in partnership with your health care provider.

If general, if you have no symptoms and did not have any close contact with positive individuals, you will be able to continue your usual activities.

If you have had close contact, you will still need to quarantine for at least seven days from last contact with the positive individual. However, actual length of quarantine will depend on whether you have ongoing exposure to the positive individual, such as a household contact.