For my study of research, I’ve decided to learn more about Covid-19 testing and its effectiveness. In this article, How Accurate Are COVID-19 Tests? Many Factors Can Affect Sensitivity, Specificity of Test Results, it discusses several methods of testing, along with how accurate the results are. The article also goes into detail about what factors can affect the tests accuracy.
Sensitive tests, which are positive results, are less likely to produce a false-positive outcome, and a specific test, negative results, are less likely to produce a false-negative outcome. Labs can provide the analytics of sensitivity and specificity for a test, which is concluded from confirmed specimens of positive and negative results. These results, however, come from when someone either had a great exposure, or none, so they are true under ideal conditions. Since there is so much variability between patients, the numbers are often lower when they are under real life conditions.
There are two main types of testing for the novel Coronavirus. The first type of test detects RNA from the virus by using methods such as, polymerase chain reaction (PCR). I have never heard of this process before, so I decided to find a source explaining what it is. PCR is used to amplify, which is making many copies of a gene or DNA. Using this process, many copies can be created, just from a small part of the DNA taken for the sample. This process can help to identify a pathogen when trying to detect a virus, such as the novel Coronavirus. This past week in class, we learned about the immune system and about the characteristics of viruses. We learned that a virus has spike proteins on the outside, and it has RNA strands in the inside of the cell. This connects to what we learned about RNA and viruses, because this test actually tests for RNA to see if a patient has the virus. they are more accurate because they are from the genetic sequence from the virus itself, which is unique to it. If a test comes back positive, it is most likely accurate. The second type of test is molecular testing. The nasopharynx is said to have the largest concentration of a virus. Since using NP swab samples, nasopharyngeal swabs, are hard to get, the sensitivity of a test can be altered or tampered. This can create a false-negative result in a patient, who really could have it. Testing with saliva and blood has more of a likeliness to reduce the sensitivity. The article also mentions that swabbing the patient in the oropharynx or nose can also have a lower sensitivity.
Antibody testing is through drawing blood from a vein, and it can detect whether or not someone was infected by Covid-19. The test uses enzyme immunoassays and rapid lateral flow immunoassays. By day 14 following symptoms appearing, most patients did have the IgG antibodies. I wasn’t exactly sure what an IgG antibody was, so I found a source to explain that in some more detail. It is an immunoglobulin and is found in all fluids within the body. They are the most common and small antibodies that are in the body. These antibodies help to fight bacterial infections and viruses. These antibodies are actually the only ones that can help protect a woman’s fetus, which is very interesting. As time goes on, it is less likely that the antibodies will be detected. There is some evidence, not confirmed yet, that suggests that children and asymptomatic or mild-symptom patients could be less likely to have detected antibodies.
I found this article to be very fascinating because it went into detail about each test and its effectiveness. I didn’t know that children and asymptomatic or mild-symptom patients were less likely to have detectable antibodies. I am excited to research more as I continue to further my studies in Covid-19 testing.