The COVID-19 test is done using reagents to extract a sample of RNA. An enzyme called reverse transcriptase converts the RNA to a complementary sequence of DNA. That DNA (called a primer) is replicated (amplified) many times over so the particular targeted DNA sequence in it can be detected. The more stages of replication the more likely the targeted sequence will be detected.
Each time the DNA in the sample is amplified it doubles the number of molecules. The doubling is exponential after each cycle of amplification. But the number of cycles can vary from laboratory to laboratory. The probability of testing positive increases as a function of the number of cycles. The PCR cycles for a COVID-19 test from most laboratories are set at 40 cycles.
John Rappaport discovered a statement by Dr. Anthony Fauci where he told other scientists during a video conclave moderated by This Week in Virology that PCR tests run at 35 or more replication cycles will give false-positive results. Anthony S. Fauci is the Director of the National Institute of Allergy and Infectious Diseases (NIAID). Dr. Fauci stated that the chance of a true positive result from 35 or more cycles is “minuscule.” He stated that the PCR tests that are being run at cycles of 36, 37, or 38 cycles are simply detecting dead nucleotides and then falsely reporting them as positive COVID-19 results.
Dr. Fauci stated: “If you get a cycle threshold of 35 or more, the chances of it being replication-confident are minuscule…you almost never can culture virus from a 37 threshold cycle… someone does come in with 37, 38, even 36, you gotta say it’s just dead nucleotides period.”
Listen to Dr. Fauci at the 4:20 mark in the video below.
How did most laboratories come up with their 40 cycle standard? John Rappaport found out that it was recommended by the Centers for Disease Control (CDC), Division of VIral Diseases. That is correct. The CDC recommended no more than 40 cycles but also stated that a positive test at 40 cycles is a positive test for COVID-19 (it is called 2019-nCoV by the CDC, which means 2019 novel coronavirus). The CDC in its official guidance to the laboratories stated:
When all controls exhibit the expected performance, a specimen is considered negative if all 2019-nCoV marker (N1, N2) cycle threshold growth curves DO NOT cross the threshold line within 40.00 cycles (< 40.00 Ct) AND the RNase P growth curve DOES cross the threshold line within 40.00 cycles (< 40.00 Ct).
Id. at 35.
When all controls exhibit the expected performance, a specimen is considered positive for 2019-nCoV if all 2019-nCoV marker (N1, N2) cycle threshold growth curves cross the threshold line within 40.00 cycles (< 40.00 Ct). The RNase P may or may not be positive as described above, but the 019-nCoV result is still valid.
Id. at 35.
The CDC has recommended 40 cycles for the PCR test and most laboratories are performing tests using that recommended 40 cycle standard. But Dr. Fauci admits that performing PCR tests to detect COVID-19 at 35 or mores cycles will result in false-positive and the confidence in any such positive result for COVID-19 is “minuscule.”
The PCR test amplifies genetic matter from the virus in cycles; the fewer cycles required, the greater the amount of virus, or viral load, in the sample. The greater the viral load, the more likely the patient is to be contagious.
This number of amplification cycles needed to find the virus, called the cycle threshold, is never included in the results sent to doctors and coronavirus patients, although it could tell them how infectious the patients are.
In three sets of testing data that include cycle thresholds, compiled by officials in Massachusetts, New York and Nevada, up to 90 percent of people testing positive carried barely any virus, a review by The Times found.
Most tests set the limit at 40, a few at 37. [North Carolina’s state lab uses the Thermo Fisher coronavirus test, which automatically classifies results based on a cutoff of 37 cycles.] This means that you are positive for the coronavirus if the test process required up to 40 cycles, or 37, to detect the virus.
Tests with thresholds so high may detect not just live virus but also genetic fragments, leftovers from infection that pose no particular risk — akin to finding a hair in a room long after a person has left, Dr. [Michael] Mina, [an epidemiologist at the Harvard T.H. Chan School of Public Health] said.
Any test with a cycle threshold above 35 is too sensitive, agreed Juliet Morrison, a virologist at the University of California, Riverside. “I’m shocked that people would think that 40 could represent a positive,” she said.
A more reasonable cutoff would be 30 to 35, she added. Dr. Mina said he would set the figure at 30, or even less. Those changes would mean the amount of genetic material in a patient’s sample would have to be 100-fold to 1,000-fold that of the current standard for the test to return a positive result — at least, one worth acting on.
Officials at the Wadsworth Center, New York’s state lab, have access to C.T. values from tests they have processed, and analyzed their numbers at The Times’s request. In July, the lab identified 872 positive tests, based on a threshold of 40 cycles.
With a cutoff of 35, about 43 percent of those tests would no longer qualify as positive. About 63 percent would no longer be judged positive if the cycles were limited to 30.
In Massachusetts, from 85 to 90 percent of people who tested positive in July with a cycle threshold of 40 would have been deemed negative if the threshold were 30 cycles, Dr. Mina said. “I would say that none of those people should be contact-traced, not one,” he said.
The PCR tests are returning false positive COVID-19 results because the cycle threshold at most laboratories has been set too high. All of the hullabaloo about the new cases of COVID-19 is hysteria over nothing.