Re: Coronavirus Fact-Check: Why “new cases” are plummeting
The conclusions being reached here are questionable.
Let’s start with what is true. The WHO did issue this memo suggesting that labs consider the cycle threshold (Ct) on Jan 13
WHO guidance for 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.
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.
Most PCR assays are indicated as an aid for diagnosis, therefore, health care providers must consider any result in combination with timing of sampling, specimen type, assay specifics, clinical observations, patient history, confirmed status of any contacts, and epidemiological information.
The conclusion reached in this persons statement implies that the PCR test is the sole conclusive test used in all labs to determine, as well as the sole conclusive criteria in determining if an individual is positive. They are not.
Secondly, do a google search on this subject and you will find scores of articles on this subject. It has been in discussion since the fall and earlier of 2020.
The concern it primarily related to surveillance programs associated with asymptomatic spread. You come off a plane and are tested, you want to go to a party and are tested, you may have been exposed and you are tested. Surveillance. It’s not related to you have symptoms, are sick, and are tested.
Read the memo and it describes the concern of identifying asymptomatic people who are no longer infectious, but the PCR sensitivity still detects the virus. Not infectious, nor symptomatic.
The memo goes on to talk about “actions to be taken”. Basically it says, take into consideration other things before concluding an asymptomatic person is infectious. This memo does not say, from now on lower the sensitivity and only count count those as as positive. It’s not a directive, it’s guidance.
So a few things regarding the conclusions reached. The memo was released on Jan13, Whomever wrote the conclusion is saying that just based on this guidance, just two weeks later positive COVID case drops over 500,000 solely attributable to this memo.
Further, it concludes that since less people as a result are diagnosed with COVID, less people are identified as dying with COVID. The fallacy in this argument is that this guidance is attempting to address the issue of people who are asymptomatic, and whose viral load is waning, and no longer infectious. The conclusion would lead you to believe, that these people were being admitted to hospitals, and dying to boot. This memo is all about asymptoMatic people who are no longer infectious. These people are not being admitted to hospitals and certainly not dying. They are getting better (even though they exhibited no symptoms), not worse, so they would never have contributed to the death toll to begin with.
Further, the conclusions reached were already reached before the article/statement was penned. It’s an attempt to find an explanation that fits the narrative.