The World Health Organization is raising eyebrows with an announcement on COVID-19 tests potentially leading to many “false positives.”
The WHO issued a memorandum that errors processing PCR (polymerase chain reaction) tests could lead to people wrongly being dubbed infected.
It is now providing guidance that the PCR tests be more carefully interpreted:
WHO guidance Diagnostic testing for SARS-CoV-2 states that careful interpretation of weak positive results is needed (1). The cycle threshold (Ct) needed to detect virus is inversely proportional to the patient’s viral load. Where test results do not correspond with the clinical presentation, a new specimen should be taken and retested using the same or different NAT technology.
It furthermore warns about a PCR test potentially getting a “false positive”:
WHO reminds IVD users that disease prevalence alters the predictive value of test results; as disease prevalence decreases, the risk of false positive increases (2). This means that the probability that a person who has a positive result (SARS-CoV-2 detected) is truly infected with SARS-CoV-2 decreases as prevalence decreases, irrespective of the claimed specificity.
The reports about PCR test “cycle thresholds” being too high is nothing new. If the cycle thresholds are too high, it suggests the viral load of the patient is too low to truly qualify as a “case.” As reported in September:
An Oxford academic warned in September that the tests could be picking up dead or deactivated viral proteins. As The Telegraph reported:
Prof Carl Heneghan, director of the Centre for Evidence-Based Medicine, said eight days after contracting Covid-19, the chances the infected person will pass the virus on “goes down to zero” if they have no symptoms.
However, he said fragments of the virus can still remain in the body for many weeks afterwards – with some studies showing intermittent shedding up to 70 days later – leading to a positive test and skewing the real picture of how many people are at risk of passing on the virus.
The BBC gave further context:
Prof Carl Heneghan, one of the study’s authors, said instead of giving a “yes/no” result based on whether any virus is detected, tests should have a cut-off point so that very small amounts of virus do not trigger a positive result.
He believes the detection of traces of old virus could partly explain why the number of cases is rising while hospital admissions remain stable.
The latest data from the COVID-19 tracking project, which coincides with the week the WHO guidance was released on January 13th, already shows the weekly cases down over 20% from last week, despite the tests going up 1%.
But since the testing guidance is coinciding with the rollout of vaccines, it will be difficult to know the precise cause of the nearly inevitable “casedemic” decline.
This is all setting up for a Biden “miracle.”
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