There are two basic purposes of performing the test that is given under below:
1:-The RT-PCR test helps to know if the patient is having an active Covid infection or not.
2:-The RT-PCR test determines the current presence of SARS-COV 2 in the patient’s body.
This technique has excellent sensitivity and specificity, meaning that it's very reliable.
However, in some situations positive results are often difficult to interpret.
The important and vital issue with the real-time RT-PCR test is that the risk of true/false or eliciting false-negative /false-positive result at a time.
It is visualized that a lot of ‘suspected’ cases with typical clinical symptoms of COVID-19 weren't diagnosed properly.
Several factors are proposed to be related to the inconsistency of real-time RT-PCR.
RT-PCR test is magnified to discuss various challenges regarding the detection of SARS-CoV-2 by real-time RT-PCR.
It is expected that this might provide beneficial information for the comprehension of the restrictions of the obtained results and to enhance diagnosis approaches and control of the disease.
It is documented that results from real-time RT-PCR using primers in several genes are often suffering from the variation of viral RNA sequences.
Genetic diversity and rapid evolution of this novel coronavirus are observed in several studies.
False-negative results may occur by mutations within the primer and probe-target regions within the SARS-CoV-2 genome.
Although it had been attempted to style the real-time RT-PCR assay as precisely as possible supported the conserved regions of the viral genomes, variability causing mismatches between the primers and probes and therefore the target sequences can cause a decrease in assay performance and potential false-negative results.
STEPS OF RT-PCR
1:- There are three basic steps for the COVID-19 PCR test:-
2:- Sample Collection: Sample collection is done by a practitioner by using a swab to collect respiratory material found in your nose.
3:- Extraction: When lab receives the sample, they perform a process called extraction
4:- PCR: It is the last step to indicate the result either it is true or false.
Eventually, we can say that the real-time RT-PCR test isn't 100% effective all the time.
As the test was giving both true and false reports, the Centers for Disease Control and Prevention (CDC) has designed a SARS-CoV-2 Real-Time RT-PCR diagnostic channel to minimize or close the deflection and visualization of false-positive results.
With this regard, the negative template control (NTC) sample should be negative, it should not show any fluorescence growth curves that cross the sting line and be in limit.
The presence and occurrence of false-positive results of the RT-PCR test with one or more of the primer and probe NTC reactions indicates that there is a chances or surety of sample contamination.
Importantly, the interior control should be included to assist identify the specimens containing substances which will interfere with the extraction of macro molecule and PCR amplification.
There might be chances of several risks to patients that shows the false-positive result, all clinical laboratories using this test for identification of covid infection in patient's body must follow the quality confirmatory testing and reporting guidelines properly.
