RE: Victoria Derbyshire8 Sep 2020 20:36
This was the bit from the FT today:
Since the virus can be spread by infected people before they feel ill or who never show symptoms, only frequent, mass screening is properly effective. But existing so-called PCR testing requires chemical reagents and specialist machines, limiting capacity and pushing up costs. There are ways of squeezing more tests out of PCR capacity, including “pooling” multiple samples to be tested together then, if any positives are detected, identifying them through a process of elimination. Such efforts should be stepped up.
At least half a dozen companies, however, are working on cheap, self-administered saliva tests using paper strips that show a marker if the virus is found, similar to a pregnancy test. The drawback is they are less sensitive than gold-standard PCR tests, only returning a positive result for perhaps 85 per cent of infected people. Regulators often approve only the most sensitive tests for a disease. Yet a growing body of medical opinion suggests that the volume and frequency that cheap self-testing would permit more than compensates, overall, for higher false positives or negatives. A positive saliva test indicator could be followed by a PCR test, with people going into isolation if that confirms the result.