The spread of Covid-19 disease is at a great speed. Some people showed symptoms of coronavirus infection but the laboratory test shows “negative” for SARS-CoV-2. In the respect of this, doctors say that the treatment is given depending on the symptoms, not for the attendance report card of the virus.
In India, two types of sample testing are approved for detecting Covid-19 — RT-PCR, the gold standard, and rapid antigen testing (RAT). If the report is “positive”, then the patient s infected. A “negative” report, particularly thrown up by RAT.
In case, if there are symptoms for Covid-19, the doctor says that it is best to begin initial treatment. For asymptomatic persons, the RT-PCR report shows “negative” then it is considered ruling out of Covid-19.
Now, the question is “why do Covid-19 test kits or machines return a negative report for a positive person?”
The answer to this question is its preservation, sample collection, transport, and final testing.
The process to test samples
RT-PCR is known as the Real-time Reverse Transcription Polymerase Chain Reaction. It is generally performed in order to identify the presence of the same virus. However, this test cannot be termed as much reliable as others for screening purposes.
To test for Covid-19 status, a swab is used to collect samples from the tissues of the throat or nostrils of a person.
This swab containing tissues that penetrate in a liquid chemical form which keeps the SARS-CoV-2 active and alive. As per the World Health Organization, it is kept in a special chamber for transportation to a pathological lab with bio-safety level-2 (BSL-2).