COVID-19 Testing: Why is it Important, How it is Done, and What Are the Challenges? by https://padlet.com/jewert3/m2k4lo56xq3y76se Why experts told us to test, how is it done, and the complications that the various tests present en-us 2020-11-25 23:59:08 UTC 2023-03-16 02:48:55 UTC hello@padlet.com The Virus that needs no Introduction jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/961947225 The Novel Coronavirus needs no introduction. It has shaken up the lives of people all over the world, and you would be hard pressed to find a human in this world who has not been affected in some way. Whether it is something simple such as cancelling travel or event plans, or more serious causing a loss of job a close family illness or death, the pandemic has had wide ranging devastating effects. This map below shows just how far COVID-19 has spread as of Dec. 5, 2020. (Find a live version of the map here)]]> 2020-11-26 00:20:18 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/961947225 Family and Structure of Sars-COV-2 jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/962271167 COVID-19 is a disease caused by the virus named SARS-COV-2 (Severe Acute Respirtatory Syndrome-Coronavirus-2) (1). COVID-19 phenotypically consists of a spherical or pleomorphic enveloped particles that contain RNA (1). Coronaviruses actually have the largest genome amongst RNA viruses (1). A single virus particle has a nucleoprotein inside a capsid comprised of matrix protein.  The virus attaches itself to cells and antibodies using  spike glycoproteins which protrude out of the virus envelope (1).
Picture Link]]> 2020-11-26 03:34:16 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/962271167 Importance of Testing early on jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/990611944 With no vaccine or certified effective treatments readily available, much of the beginning of the COVID-19 pandemic was focused on testing in order to contract trace and stop the spread of the virus. Tracing and testing people in close contacts are important, because the virus has such an original transmission rate of between 2-2.5, a rate considered high by the WHO (2). Testing is also important due to the similarity of the symptoms of COVID-19 to many other infections such as the common influenza, therefore it it important for people infected to know exactly what disease they have (3).]]> 2020-12-05 20:52:34 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/990611944 Viral Test: RT-PCR jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/990748100 Viral tests for COVID-19 tell the patient if they currently have COVID 19 by detecting the presence of the genetic material (RNA) of the Virus (4)  One of the most common versions of these tests is the RT-PCR test (Reverse Transcription Polymerase Chain Reaction) (5).  In this test, swab RNA samples are collected from from upper or lower respiratory areas, then reverse transcribed into cDNA where it is the DNA is then amplified (5).  These tests continue to be a test that is high in demand. In Canada there are 2.19 test performed for every thousand people, and 3.22 per thousand in the U.S., as of December 5th. (Click here for live updated testing numbers). Curious about how the testing process may unfold? Watch this video by CBC News to see how it works!]]> 2020-12-05 23:44:31 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/990748100 Antibody Test jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/991125677 The little known, less useful brother of the viral test is the COVID-19 antibody test. This test determines cases of past infection of COVID-19 by testing your body's blood for the presence of antibodies created to neutralize the effects of virus (6). The antibodies created by the human immune act against the receptor-binding domain of the spike protein as well as the nucleocapsid protein (6). Unfortunately, this test cannot be relied on to tell us if we are currently infected with the virus, as the antibodies only begin to appear on a minimum of 1-3 weeks after the onset of symptoms (7).]]> 2020-12-06 08:04:17 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/991125677 Advantages jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992402782 The first and obvious advantage of the viral test is that it is a widely approved and trusted method to tell us if someone is currently infected with COVID-19 (4). This makes the RT-PCR test one-of-a-kind. Another advantage of the RT-PCR test is its amplifying ability, allowing the RT-PCR test to still succeed when there is low amounts of virus particles in the body (8). This can be extremely important to detection if the virus is present in low amounts in a patients body.  While officials all  constantly trying to approve tests that are faster, no other diagnostic test has been as widely approved as the RT-PCR test. Some argue that its accuracy, which is discussed below, is one of its greatest strengths as well, but I will leave that up to you.

Here is where exactly the swab is trying to touch for a successful RT-PCR test!
Image Link:

]]> 2020-12-07 00:31:31 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992402782 A Couple Disadvantages jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992494413 While the disputed accuracy challenges can be seen as a potential disadvantage of the RT-PCR test, there are a couple of indisputable disadvantages of this testing method. The first drawback to this method is the cost and resources each test analysis requires. Each test requires analysis in a certified laboratory that contains all the necessary equipment and software. These requirements make testing quite expensive. For example, in July testing was costing Canada $2.4 million dollars a day (11). Many people in the public are asking "Why do we not test more?" Well, to use another example, if Canada were to test all hospital workers daily, it would cost $29 million dollars a month (11). If these tests were less costly, perhaps more preventative testing could be done. Another disadvantage of this method is the amount of time taken to receive results. The previously discussed procedure of the test plays a big role in the delay in test results, as an RT-PCR test cannot be carried out instantly. The average RT-PCR test actually takes about 6 hours from start to finish (12). A method used by laboratories to help reduce processing time is pool testing. Poll testing involves mixing batches of tests together in 1 pool, then running 1 test on the entire pool (13). Pooling can be especially useful in areas with low case prevalence where tests often come back as negative.
Another factor contributing to the time delay for results is the lack of nearby labs that process the test. Transport time to a processing lab can take a long time, and that transport time can be different depending on where you live (12)  For example, all testing in British Columbia was originally centralized to one laboratory (14) Now, more and more laboratories are participating in test processing, but most labs are clustered around major population centers, making transport time a major factor for certain residents awaiting results (14). Below is a list of labs that process tests in British Columbia:
Image link]]> 2020-12-07 01:23:46 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992494413 Advantages of the Antibody Test jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992753726 While to most this test may seem rather useless when compared to its world famous counterpart, there is indeed some advantages (besides getting some personal clarity on a past sickness). Firstly, people who do test positive for COVID-19 antibodies can have their blood used to help treat those battling COVID-19. For example, Covalescent plasma therapy, which involves using the antibody rich blood of COVID-19 survivors to help  treat current patients (15). Due to the antibodies role in this treatment, widespread antibody testing could end up being lifesaving because the more people who know they have the antibodies, the more opportunities to donate blood there are. 
Another benefit of this test is the speed of the results. While the RT-PCR test can several take days to get results, the antibody test can produce results in just 15 minutes, much quicker than the often multiple day process of the RT-PCR (16). Another positive of these tests is that they can even be be carried with at home kits. Watch one in use! (Credit to Nature)]]> 2020-12-07 04:00:38 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992753726 Accuracy jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992869963 There have been wide ranging claims made about the accuracy of these diagnostic viral COVID-19 tests. Incorrect tests can either be false negative or false positive False negative tests have a wide ranging accuracy, with one systematic review study suggesting 2-29% of negative results were indeed false (9). False positive tests are considered to be much more rare, and most can be traced back to cross or accidental contamination. In fact, many researchers believe that the RT-PCR test is almost 100% accurate if carried out correctly (10). This means that the test has a high specificity for the RNA that it tests for, meaning it does not confuse the SARS-COV-2 virus paticles with another virus (10).  While incorrect results do cast a shadow of doubt on testing the PCR test does continue to be the best available diagnostic option.  ]]> 2020-12-07 05:10:07 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992869963 Accuracy jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992875757 When it comes to the antibody test, there is even more uncertainty in regards to accuracy. On the surface, they seem fairly accurate. In fact, one of the FDA's only approved tests has a 94% true positive rate, which is quite effective (16). However, there are many antibody tests out there that aren't approved, many with much lower quality and accuracy (15). False positives are a major concern in the low quality tests, as the tests can often mistake Sars-COV-2 antibodies for antibodies of other coronaviruses or related diseases (17).]]> 2020-12-07 05:13:35 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992875757 Disadvantages jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992986346 As discussed earlier, one of the disadvantages of this test is its lack of functionality. It is once again important to note that antibody tests  can only be relied upon to diagnose past infections. It is also important to note that possessing the antibodies does not mean you are immune to COVID-19, as reinfection has occurred. Although reinfection with COVID-19 is rare and typically results in less severe symptoms, people who are re-infected can still "shed virus particles" and continue to spread the virus (18). People who are unaware that they can get re-infected could be given a dangerous false sense of immunity, and endanger the public.   ]]> 2020-12-07 06:16:48 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/992986346 What is a Rapid Antigen Test jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/993043288 What if we could combine the speed of the antibody test with the RT-PCR's ability to diagnose a current case of COVID-19, all for $5 (U.S.)? Well that is exactly what the Rapid Antigen Test is trying to accomplish.
The rapid antigen test determines for the presence of an infection by detecting the antigen proteins present on the outside of a virus particle. Samples are taken through swabbing, similar to the RT-PCR test, but companies are working towards a less intrusive saliva sampling as well (19). The swab is mixed in a solution that frees the virus proteins. Once mixed, the solution is then added to a paper containing antibodies created to specifically bind to the antigen proteins(19). If the proteins are present, the antibodies bind and the paper changes color produces a dark strip of fluorescent glow, indicative of a positive test and an active case of COVID-19 (19).
Watch this this video explaining how the Abbott Labs Rapid Antigen Test is carried out! (Credit to ABC 7 News Chicago).]]> 2020-12-07 06:46:09 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/993043288 The exciting advantages of the Rapid Antigen Test jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/993143642 The most intriguing factor of the rapid antigen test is indeed the short amount of time it takes to get test results, typically in 15-30 minutes, which is a pittance of time when compared to the often several day process of the RT-PCR test (19). Not only would reducing the time of test analysis allow for more testing, but it would drastically minimize the uncertainty and stress that is involved with awaiting test results. Also if widely approved, it could help eliminate the quarantine periods following travel in many countries.
The antigen test is also much easier to carry out, which makes it much cheaper for governments and consumers. All current antigen tests are point of care tests, making them easy and attractive to carry out (20). The analysis of the test provides results without the need of  a laboratory, machines, or expensive software, all 3 of which the RT-PCR test requires (19). The lack of resources needed makes the rapid antigen test easier to perform, and perhaps more importantly, cheaper. These kits are available at a cost of only $5, making them much cheaper than a RT-PCR test for both the government and consumers (19).
Does all this seem too good to be true?

Below is a photo of Abbott Laboratories $5 test kit.
Image link]]> 2020-12-07 07:36:08 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/993143642 The Catch jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/993210423 While the Rapid Antigen test may be fast, easy, and cheap, it lacks in a key area: accuracy. Rapid antigen tests appear to have wide ranges of accuracy. For example, one rapid antigen test by Abbott has shown to have 95-100% accuracy when taken within 1 week of symptom onset, while only 75% when taken over a week after symptom onset (19). 
The Abbott test has proven to be one of the most accurate, as a different antigen test used to test masses of people in India was found to only be displaying 51-84% accuracy (19).
Some of the basis of the inaccuracy may be a result of the high limits of detection of antigen test, meaning that samples must contain a large amount of virus particles for the test to produce a positive result (8). For comparison, RT-PCR test, (the test which the rapid antigen test is trying to replace) has an extremely small limit of detection, as it can amplify a single RNA molecule (8). 
As a result of the inconsistent results of the antigen test, many governing bodies including the WHO and CDC suggest individuals a RT-PCR test if the they show symptoms following a negative COVID-19 antigen test (19).]]> 2020-12-07 08:07:51 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/993210423 jewert3 https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/995908451 1. https://doi.org/10.1016/j.jmii.2020.03.022 
2. https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf
3. https://www.who.int/westernpacific/news/q-a-detail/coronavirus-disease-covid-19-similarities-and-differences-with-influenza
4. https://www-bmj-com.prxy.lib.unbc.ca/content/370/bmj.m2516
5. https://www.fda.gov/media/136151/download#:~:text=The%20COVID%2D19%20RT%2DPCR%20test%20is%20a%20real%2D,respiratory%20tract%20aspirates%2C%20bronchoalveolar%20lavage%2C
6. https://www-sciencedirect-com.prxy.lib.unbc.ca/science/article/pii/S147330992030517X

7. https://www.cdc.gov/coronavirus/2019-ncov/testing/serology-overview.html
8. https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v3.full.pdf
9.https://www.bmj.com/content/bmj/369/bmj.m1808.full.pdf
10. https://www.health.harvard.edu/blog/which-test-is-best-for-covid-19-2020081020734
11. https://link.springer.com/article/10.1007/s40274-020-7162-1
12. https://www.npr.org/sections/health-shots/2020/03/28/822869504/why-it-takes-so-long-to-get-most-covid-19-test-results
13. https://www.cdc.gov/coronavirus/2019-ncov/lab/pooling-procedures.html
14. http://www.bccdc.ca/health-info/diseases-conditions/covid-19/testing/phases-of-covid-19-testing-in-bc
15. https://www.hackensackmeridianhealth.org/HealthU/2020/05/02/covid-19-antibody-testing-pros-cons/
16.
https://medical.mit.edu/covid-19-updates/2020/07/how-accurate-are-fda-approved-covid-19-antibody-tests
17. https://www.webmd.com/lung/qa/how-accurate-are-antibody-tests-for-covid19
18. https://cihr-irsc.gc.ca/e/52190.html
19. https://www.nature.com/articles/d41586-020-02661-2#ref-CR1
]]> 2020-12-07 20:22:16 UTC https://padlet.com/jewert3/m2k4lo56xq3y76se/wish/995908451