Last Updated on June 8, 2020 by Sagar Aryal
While coronavirus continues to hit different places all over the world, medical experts are also looking for ways to alleviate the situation. There’s no cure yet that can eradicate the virus, so testing is the only way to control the situation.
Though there are numerous attempts to develop more tests, current options are limited in type, availability, and accuracy. Because these tests are essential tools to screen, diagnose, and monitor COVID-19, careful measures are necessary to produce the right information. Otherwise, lives will be compromised, making it harder to contain the virus.
Listed below are different types of COVID-19 tests healthcare providers worldwide have been using. Each type plays a role in the fight against COVID-19, and while they bring several advantages, each has limitations that are vital to consider.
Image Source: Pexels.
Tests To Detect COVID-19
Many available tests are earning emergency approvals to detect COVID-19. However, the FDA is still working around the clock with test developers to streamline the testing process.
There are two types of tests currently available in the medical field: the diagnostic test and antibody tests. Each test involves different methods to generate results.
A diagnostic test can reveal if you currently have an active coronavirus infection. These tests are composed of molecular (RT-qPCR) tests and antigen tests. If the result shows you’re infected, you would be required to quarantine or isolate yourself.
Molecular (RT-qPCR) tests are used to detect the genetic material of the virus. Most of the molecular tests require samples taken through a nasal or throat swab, while others need saliva. Since this test is highly accurate in most cases, it is the standard in determining whether a person has the virus or not.
On the other hand, antigen tests are used to detect specific proteins on the surface of the virus. Like molecular tests, samples are taken from the nasal or throat swab. It’s also called a rapid diagnostic test since it only takes one hour or less to get the results.
Antibody tests, also known as serological tests, look for antibodies produced by the immune system when there is a threat of a specific virus. A sample is taken through a finger stick to draw blood.
Antibodies can take several weeks to develop after an infection, and may also stay in the blood for weeks, even after recovery. As a result, serological tests aren’t ideal for diagnosing infection.
Advantages and Limitations
Confirming those infected is essential to manage and contain the virus successfully. Without reliable testing, it would be hard to determine the actual rates of cases. Thus, it is vital to identify what these available tests can and can’t do to use them appropriately.
Molecular (RT-qPCR) Tests
Due to its adequate sensitivity, RT-qPCR tests are the gold standard when detecting coronavirus. It can diagnose active infection and doesn’t need to be repeated because of its high accuracy. However, it would take up to a week to get the results.
A significant issue with the RT-qPCR test is the probability of generating false-negative and false-positive results. Although it was designed to be as accurate as possible, the sensitivity and specificity are still not 100%. One factor that largely contributes to the false-negative results is the sampling procedures.
One study (https://doi.org/10.1515/cclm-2020-0187) reported that sputum is the most accurate sample for testing, followed by nasal swabs. However, throat swabs are not ideal for the procedure.
By using antigen tests, the presence of the virus can be confirmed within minutes to hours. The viral antigen is detectable at the first sign of COVID-19. However, it will only show if the patient has a current infection. It cannot indicate recovery from the virus.
The results of antigen tests are usually accurate, but negative results need to be confirmed with RT-qPCR assays, especially when an individual is showing COVID-19 symptoms. Compared to molecular analysis, this test has more probability of missing an active infection.
While these tests cannot be used to diagnose active coronavirus infection, it still plays a significant role in the fight against COVID-19. These tests can help identify individuals who developed antibodies that can protect them from future infections.
Serological tests can help determine who is qualified to donate blood that can produce convalescent plasma. It’s a product that is still under clinical trial and utilized by those who are seriously ill from the disease.
Who Should Be Tested?
With the public’s demand to make mass testing available, it’s essential to consider why it’s not happening yet in countries around the globe. One is the availability of reliable and large-scale testing kits. Aside from that, there’s a scarcity of health providers who can administer the tests and validate the results.
Since mass testing seems to be unlikely, who should get tested? The Centers for Disease Control and Prevention has released a specification and guidance of testing priorities. However, decisions about testing are still to be made by state and local health departments and providers.
A Friendly Reminder
Only healthcare professionals should utilize these coronavirus test kits. In case you manifest symptoms of COVID-19 and want to get tested, contact your healthcare provider first. Regardless of the result and the type of test performed, you still have to take preventive measures to protect yourself and others.
It’s essential to remember that no test has 100% percent accuracy, and clinical judgment of healthcare providers matter for the appropriate use of these tests. Despite the limitations, these tests are still the best weapon we have against COVID-19. Through testing, our anxieties are lessened, while more cases can be detected, treated, and recovered.
References and Sources
- 2% – https://www.fda.gov/media/138094/download
- 2% – https://www.cdc.gov/coronavirus/2019-ncov/faq.html
- 1% – https://www.testing.com/when-to-get-tested-for-coronavirus/
- 1% – https://www.questdiagnostics.com/home/Covid-19/Patients/
- 1% – https://www.mayoclinic.org/diseases-conditions/coronavirus/symptoms-causes/syc-20479963
- 1% – https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-serological-test-validation-and-education-efforts
- 1% – https://nymag.com/intelligencer/2020/05/coronavirus-antibody-test-what-is-it-and-how-to-get-one.html
- 1% – https://medical.mit.edu/faqs/COVID-19
- 1% – https://en.wikipedia.org/wiki/Testing
- 1% – https://en.wikipedia.org/wiki/COVID-19_testing
- <1% – https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/testing.html
- <1% – https://www.berrydunn.com/blog/covid-19-faqs-for-nonprofits
- <1% – https://en.wikipedia.org/wiki/Sensitivity_and_specificity
Disclaimer: This is the sponsored guest post from Abigail Edwards. She is a part-time writer with vast expertise in topics regarding human biology and chemistry. She loves learning about science and shares her knowledge with the subject through her writing. Due to her hunger for learning, Abigail would dedicate her free time studying new scientific discoveries and scholarly articles.