Covid 19 Part XXXV-956,720 ROI (5,952 deaths) 452,946 NI (3,002 deaths) (08/01) Read OP

Stormyteacup wrote: »

Yes but from your link;

‘When it is not practical to implement the process outlined here and no differentiation
between a positive result (unqualified) and a positive result qualified as high Ct value
/low viral load is accessible it is necessary to proceed on the basis that a positive test
is evidence that a person is infectious.’

And also;

‘Interpretation of results is dependent on the availability of Ct values/viral load. Laboratories may not report Ct values routinely but should provide the result in the context of expert interpretation on request. If Ct values/viral loads are not available for any reason (for example some platforms do not display Ct values) the default is to assume a positive result represents a significant result and that the person is infectious. It may be appropriate however to retest the sample on a platform that does display Ct values.’

Guidance is reasonably clear but do you have any information on how many reporting labs have platforms that display CT values (I don’t know - could be 10%, could be 90%)?

An example of guidance being clear but not possible is the ‘one entrance, one exit’ guidance for hospitality. All good if you’ve two entrances, but many don’t and so guidance doesn’t apply.

CT cycles run to 40 and admittedly high CT returns are few But imo the guidance is loose. Labs are unlikely to be comparing each sample with sample history for prior symptoms, prior infection, and local community level of infection, for every sample collected. And the director of each lab makes the call for cutoffs, there’s no regulation as such.

What I’m saying is it’s hardly an unequivocally scientific streamlined collection of data. There is much open to interpretation based on personnel, and on system capability.

Plus, that document is from April this year - is it possible that prior to then the thresholds for ‘detected’ were higher? What were the guidelines last October for example? Are the current comparisons for antigen vs PCR from recent PCR reporting guidelines or from last year?

Yes PCR is the gold standard, but its drawbacks are sensitivity and time limitations - at this stage of vaccination rollout and infection control, while pressing on with hopefully resuming normal life, we should be employing antigen tests in certain situations/locations to manage transmission as an additional tool, where their advantage is accessibility, cost and faster result.

Martina1991 wrote: »

I haven't looked at what other countries did as far as trialls before implementation. I'd guess that many went from the manufacturers sales pitch to handing them out to he public without thorough review.