The coronavirus disease or Covid-19 is a deadly infectious disease that had emerged in Wuhan City, China and had spread across the whole world. People who are infected with the disease will develop a range of different severities of the symptoms, from mild and asymptomatic to life-threatening. Generally, the most noticeable symptoms of COVID-19 are cough, sore throat and shortness of breath. However, over the following months, researchers have found that it may also affect other organs besides the lungs, such as the heart, brain, kidney and liver, posing additional challenges to manage and treat the disease. The pressing matter has brought the attention of researchers and manufacturers to come up with different types of coronavirus tests to screen and diagnose patients. There are a few COVID wellness packages to keep oneself save.
There are three main types of coronavirus tests. They are the PCR test, antibody test and antigen test. The Covid-19 test procedures are different from each other and they use different principles to derive the results.
Here are the things you should know about the three main tests.
Also known as a polymerase chain reaction, is a complex procedure that uses the genetic materials of the coronavirus from collected samples, amplifies it and use the amplified specimen to detect the presence or absence of the virus. The amplification process is crucial in this test because it allows the machines to detect a sample that has a very scarce amount of the viral genetic materials, hence effectively improving its accuracy in detecting the presence of viruses in the body.
Generally, a health worker will use a long swab (6-inches) to collect specimens from the back of your nose or throat. The swab will be inserted from the nose with the head slightly tilted upwards, once the swab reaches the back of the nasal cavity, it is rotated several times to ensure adequate specimens are collected. The specimen will be sent to a lab with the capacity to run RT-PCR tests and results can be obtained within 1 to 7 days, depending on many factors.
RT-PCR is the most accurate diagnostic test to date and also the most sensitive to determine whether someone is currently infected with the virus. However, to conduct this test, it requires expertise and highly specialised equipment, hence, posing a challenge to make it available at all health centres.
An antibody test is a serology test, and what that means is, instead of detecting the virus present in the system, the test detects the antibodies that are fighting off the virus. If a person was infected with the coronavirus, the immune system will immediately develop antibodies against the virus and this is exactly what the test is detecting.
The antibody test requires the blood of the person, and this can be obtained either by a small finger prick or taken directly from a vein. The blood will then be sent to laboratories equipped with the capacity to run the antibody tests.
Antibody tests cannot be used for a definitive diagnosis. It lacks the most fundamental requirement of a test and that is accuracy. However, it has other uses. It could measure the body’s immune response to a disease, predict the possibility of a person being reinfected, to see if the person is immune to the disease or for scientific research.
Antigen tests are similar in principle to a pregnancy test kit. A sample from the patient’s blood, serum or plasma is obtained and drops of the specimen are added onto a cassette together with a reagent. The test will take 5-10 minutes before lines appear and can be interpreted.
The test is inconsistent and does not yield accurate results. However, it can be a rapid screening tool to quickly identify those with a high likelihood of being infected with those who have not contracted the virus. The upside of this test is that it is simple to use, quick and theoretically able to be produced on a large scale and made available to all.