Thread by @PerpetualValue

Kind of remarkable how SB points out many of the flaws of the PCR test in this paper, yet say that the critique is 'Without any credible evidence'

Most of the tests in the UK&EU use only 1-2 target genes and run up to 45 cycles

How much has he been been paid for this paper?

https://twitter.com/StephenABustin/status/1366374723953827842

Stephen Bustin, peer reviewer of Corman-Drosten:
- whilst the mere presence of viral RNA is not necessarily indicative of whether an individual can still transmit the virus to others

- it is also clear that higher viral load is associated with increased disease severity and mortality
- and, indeed, that viral load at admission independently predicts mortality

- Hence the ideal testing regimen would involve not just qualitative detection of SARS-CoV-2 but reliable and meaningful quantitative reporting of viral loads.

- there are currently no certified quantification standards,
RNA extraction and inhibition controls, or standardised reporting procedures

- There can be no doubt that PCR-based tests must be judiciously designed, carefully optimised and extensively validated before use, be that as research or as diagnostic tools

- This enterprise has met with a mixed response, with many research publications failing to meet acceptable
standards of reporting, appropriate experimental design, protocols or data analysis

- This test, targeting three SARS-CoV-2 genes, was not ideal as primer and probes were not optimised and it was not as sensitive as later iterations.

Actually most tests are done on 1 or 2 target genes

- Nevertheless, technical challenges and interpretative hurdles associated with SARSCoV-2 detection have been evident for a long time

- RNA quantity, quality and integrity have major bearings on the reliability of any RTPCR-
based test

about FP:
- This has re-emerged as a problem during the current pandemic, where reagent contamination, sub-optimal PCR conditions or inadequate laboratory process control
practices can quickly lead to major problems associated with amplicon contamination across laboratories

- False-positive results are a particular problem when prevalence is low, and the potential for adverse consequences includes unnecessary contact tracing, inappropriate treatment, removal of key workers and delayed or impeded appropriate medical treatment

- It is also important to note that there is currently no standard measure of viral load in clinical samples and that there is an obvious need to include a validated
reference marker with diagnostic assays to make different workflows, protocols and assays
comparable

- Taken together, these data strongly argue the case for standardisation and availability of calibration controls to obtain reproducible Cqs, which must then be combined with large scale test results and correlation with patient data to be translated

into clinically useful information.
- the public health management of RT-qPCR testing programmes in many countries has been wholly inadequate, poorly organised and consequently, frequently ineffective

- This has resulted in widespread confusion,
misperceptions and misinterpretation of RT-qPCR testing results [99], to the point where the undisputable uncertainties surrounding the relevance of detecting low levels of viral RNA have been hijacked by

an assortment of special interest groups.
- this has led to significant challenges with regards to the understanding of those results, especially when they are
pertaining to evaluating the clinical relevance of very low viral loads.

- The pre-analysis steps that comprise sample collection, storage, transport and processing must be standardised and optimised, since the best RT-qPCR assay cannot perform adequately on a sub-standard sample.

- Ideally, kit manufacturers should release the sequences of both primers and probes.
- The evident lack of certified standards or even validated controls to allow for a correlation
between RT-qPCR data and clinical meaning requires urgent attention from national standards and

metrology organisations, preferably as a world-wide coordinated effort.
- In the absence of such standards, whilst lower Cq-values generally correlate with
higher levels of viral RNA, the quantification and precision associated with differences
in Cq-values, especially at levels

close to the limits of detection, have not been
established. As a consequence, the concept of “high Cq” is vague and hence ambiguous, its translation into a clinically valid assessment of infectivity remains a matter
for discussion and results must be interpreted judiciously.

YET, the critique is 'Without any credible evidence'.

Wow!!!!!!!!!!!!!

@Kevin_McKernan @goddeketal @angelovalidiya @BorgerPieter @Thomas_Binder @Bobby_Network