COVID-19 test is Rapid and widespread. Tracking, tracing, and isolation (TTTI) have become essential to public health policy response to the Corona Virus Disease 2019 (COVID-19) epidemic. Several tests for CoVID-19 have been developed. And each has its pros and cons. Effective testing strategies can combine different tests to achieve complementarity. Given their respective advantages and disadvantages.
Types of Covid-19 test
There are two types of COVID-19 tests designed to detect active infections. And they can be divided into molecular tests and rapid antigen tests. The third type of test. Is the antibody test. Can be used at any time. RT-PCR and LFT are different antigen tests and are covered below (1 and 2). Followed by a brief look at antibody tests (3) to detect previous encounters with the virus. Designed for
Reverse transcriptase – Polymerase chain reaction (RT-PCR) is the best available technique and is used to screen for the presence of RNA. Which is understandable in the early stages of infection – before Giving the body a chance. Prepare antibodies for infection. This test works by enabling RNA molecules to be detected by reverse transcriptase (or DNA polymers can also be used). This is a very specific and sensitive test. Although it is cheaper to get results because samples are sent to the lab to get results. The high cost of this type of test has greatly limited its use. Other disadvantages include:
- Positive results different to interpret
- Limitations on supply of essential testing materials ––nasal swabs, reagents. Transport media
- Long lead times (in addition to lab processing time) due to the logistics of transporting samples etc.
Point of care RT-LAMP test
The RT-LAMP test is similar to the RT-PCR test but can be used for point-of-care testing without the need to send the sample to a laboratory. Thus negating the loss of long lead time.
This type of test works by identifying a sequence of SARS-CoV-2 RNA and cutting off any nearby single-stranded RNA. As a result of the cuts. A separately introduced fluorescent particle is released into the test solution. Which can later be detected by a laser. Thus indicating the presence of genetic material.
These serological tests cannot be used to diagnose existing COVID-19 disease. But to tell if an individual has had the infection before. These tests are significant in the comprehension of contamination rates in a populace and are of epidemiological worth. This type of test is also helpful because many people do not have any signs of infection and therefore can become infected without knowing it. Counter-acting agent testing has been used to identify a safe response in people vaccinated against SARS-CoV-2. This type of test requires an example of taking blood from patients as opposed to a direct broom.
The tests come in many structures. From the complex and lab-based (e.g. ELISA tests) to the less complex fast tests utilized at the mark of care.
Albeit these tests assume a significant part in the study of disease transmission and immunization advancement. Given that they are unsatisfactory for identifying a flow. And dynamic viral contaminations. They assume no part in carrying out TTTI procedures. At long last. How long the resistance to antibody stimulation will last is currently a dilemma for researchers. As the danger of new variations poses a potential threat. The requirement for sponsor immunizations is a consistently present possibility.
Which test and when?
The advantages and disadvantages of different testing strategies mean that we choose the most appropriate method according to the circumstances. They should depend on the purpose of the test in the first case. The goals given are:
- Medical care needs, include the need to inform patients about medical decision making for accurate diagnosis.
- TTTI strategies ––accurate diagnoses for confirming or disconfirming suspected cases. E.G. Because a person was symptomatic or else encountered someone who tested positive for the virus.
- Epidemiological monitoring of specific populations ––e.g., groups of people such as in nursing homes, and schools. And universities. Companies. Geographic localities.
There is no testing strategy that is effective in all three scenarios above. But there are some benefits to using a given test for a specific situation. For example.