The strain of Covid-19 "Omicron" may not be determined by the PCR test. In approximately one third of cases of human infection with a variant of the coronavirus, the Omicron PCR test can show a negative result. Doctor of Medical Sciences, professor Sergey Kramarev told about it.
"The sensitivity of PCR tests, according to the most optimistic estimates, is up to 80%. That is, 20% or even 30% of the results can be false negative. PCR can not see not only "Omicron", but also other viruses," the doctor noted.
According to him, the sensitivity of ELISA and express tests is even lower than that of PCR tests, and the possibilities of PCR diagnostics are limited by false results of up to 20-30%.
"There are separate tests for separate strains, for example, for "Delta", for "Omicron". But all the same, the possibilities of PCR diagnostics are limited by false results up to 20-30%. When the doctor knows that the patient had contact with a sick coronavirus, when the symptoms are similar to COVID-19, PCR tests are done several times. Sometimes we get a positive result for the second or third time," added the professor.
