What are the various kinds of Covid-19 tests?
There are two primary types of Covid-19 tests: antigen and antibody tests. Antigen tests look for the virus itself, while antibody tests look for antibodies to the virus.
Antibody tests are more common because doctors can use them to detect active infection or immunity to the virus. However, they cannot tell you if you are currently infected with Covid-19, for that, you’d need to take an antigen test.
PCR (polymerase chain reaction) tests are sent away to a lab for diagnosis. They are much more accurate than LFTs (liver function tests) but take longer to get results. LFTs can be used to diagnose Covid-19 on the spot, but they aren’t as accurate as PCR tests.
What is a PCR test?
A PCR, or polymerase chain reaction, test is a diagnostic medical test that detects the presence of a particular virus in the blood or saliva. The test works by looking for genetic material from the virus. Even if you are no longer infected, the virus may leave traces of its genetic material.
PCR tests can analyze both blood and saliva samples, but the deep nasal swab technique is most common. This technique involves taking a sample from inside your nose using a long Q-tip-like device.
The new Accula PCR test can provide results in 30 minutes-much faster than traditional PCR tests. If you’re feeling sick and want to know right away if you have a viral infection, this is the test for you!
The PCR test checks for viral infections such as SARS (Severe Acute Respiratory Syndrome) or CoV (Coronavirus). It’s an essential tool for diagnosing these illnesses and helping to get you on the road to recovery fast.
What is an antigen test?
An antigen test is a laboratory test that detects proteins on the surface of viruses. Antigen tests, although providing accurate answers within 15 to 30 minutes and with a high degree of speed, have a greater probability of false negatives than PCR testing.
Once infected, a patient sheds the viral load in their system, with levels fluctuating dramatically during the infection. Performing a test too early (or too late) can result in a false negative; nevertheless, antigen testing will identify an ongoing infection.
Antigen testing is still considered the first line of defense since it provides findings in minutes, does not involve laboratory procedures, and is less expensive. You may perform even antigen testing at home; the Department of Health and Human Services will give you four free tests if you contact CovidTests (tests predicted to dispatch within 7-12 days).
Critical differences between PCR and Antigen tests
PCR (polymerase chain reaction) and antigen tests are two of the most common ways to test for viruses. However, there are a few key differences between these tests that you should know.
First, PCR tests are more accurate and reliable than antigen tests. This is because PCR testing considers the entire genome of the virus, while antigen tests only look for a specific protein or peptide from the virus. As a result, PCR tests can detect even tiny amounts of viral DNA or RNA, while antigen tests may not be as sensitive.
Second, PCR testing takes hours to complete, while an antigen test only takes 15-30 minutes. This means that rapid antigen tests are most accurate for symptoms that have only just started. Additionally, rapid antigen tests are also more accurate when used within a few days of the start of your symptoms.
Thirdly, PCRs detect current or recent infection, while NAATs will detect infection anywhere in the body. The NAATs can be administered through nasal swabs, nasopharyngeal swabs, oropharyngeal swabs, and sputum specimens. In contrast, PCRs require blood samples or tissue biopsies for analysis.
Fourth, NAATs have higher specificity than they do in the case of antigen tests, and this means that NAATs are more likely to give a correct diagnosis than an antigen test. However, both PCR and antigen tests can be subject to false positives and negatives.
Fifth, the complexity of each type of test varies. PCR tests are generally considered to be more complex than antigen tests. However, NAATs are easier to use than either PCR or antigen tests.
Sixth, PCR tests are more sensitive than antigens, which means that they can detect smaller amounts of viral DNA or RNA. As a result, PCRs are often used in point-of-care settings, such as a doctor’s office or even at home.
Finally, while antigen tests are less sensitive than NAATs overall, they may be more sensitive when used for symptomatic persons or if a virus is present. In contrast, NAATs have lower specificity in these situations.
Types of samples
Many types of diagnostic samples can be used to test for COVID-19. The most common sample type is a swab from the nose and throat.
Swabs are easy to collect and do not require any special training. Other types of samples include anterior nares, mid-turbinate, nasopharyngeal, oropharyngeal, and saliva. Nasopharyngeal sampling requires a trained health care provider.
Diagnostic tests can show if you currently are infected with SARS-CoV-2, the virus that causes COVID-19. COVID-19 diagnostic tests can be performed at a laboratory, a standalone testing site, or in the doctor’s office.
Most COVID-19 tests use an anterior nares (nasal) swab sample. For some COVID-19 tests, you have to go to a lab. There are FDA authorized at-home tests for COVID-19 which offer the option of self-testing where it is convenient for you.
When to take a PCR test and when to take the antigen test
The COVID-19 strain is a respiratory virus that affects the lungs, mouth, and throat, so you must get tested if you experience any of these symptoms.
There are a few critical differences between PCR and antigen tests that you should be aware of before deciding which one to take. The gold standard for COVID-19 testing is the PCR test, but it can take a few days for the results to come back. If you’re in quarantine and need to know right away whether or not you’ve been exposed, an antigen test may be better for you.
Remember that these tests are not 100% accurate, so it’s essential to do other things besides testing to protect yourself from COVID-19.
