Whilst all the discussion concerning Covid and its spread is interesting, it is important to note that the figures with which we are bombarded each day are scientifically contentious and may not mean what we think they mean, or have the weight attached to them that the media is keen to lay upon them. The swab test for Covid is thought to present at least 0.8% False Positives. That seems insignificant, but figures we see quoted daily to represent the spread of cases are quoted per 100,000. I'm no mathematician but I can do 0.8% of 100,000 ......... So the following is from a government website published in June -
What is the UK operational false positive rate?
The UK operational false positive rate is unknown. There are no published studies on the operational false positive rate of any national COVID-19 testing programme.
An attempt has been made to estimate the likely false-positive rate of national COVID-19 testing programmes by examining data from published external quality assessments (EQAs) for RT-PCR assays for other RNA viruses carried out between 2004-2019 [7]. Results of 43 EQAs were examined, giving a median false positive rate of 2.3% (interquartile range 0.8-4.0%).
Why are false positives a problem?
DHSC figures show that 100,664 tests were carried out on 31 May 2020. 1,570 of those tests were positive for SARS-CoV-2 (1.6%). The majority of people tested on that day did not have SARS-CoV-2 (98.4% of tests are negative). When only a small proportion of people being tested have the virus, the operational false positive rate becomes very important. Clearly the false positive rate cannot exceed 1.6% on that day, and is likely to be much lower. If the operational false positive rate was 0.4%, 400 of the 1,570 positive tests would be false positives. That would represent 400 people being isolated when they are well, and much wasted effort in contact tracing. It is possible that a proportion of infections that we currently view as asymptomatic may in fact be due to these false positives. Unless we understand the operational false positive rate of the UK’s RT-PCR testing system we risk overestimating the COVID-19 incidence, the demand on track and trace, and the extent of asymptomatic infection.
Back to me - all kinds of bits of old virus apparently give a false positive. If the data is inaccurate the conclusions are going to be dubious. Maybe that's why the best we come up with is the Eyam approach to the Plague.
For all the science, tests don't differentiate between infected and infectious. So TheoLuddite on here may be right to talk about superspreaders, because evidence we do have is that whilst some infected people come into contact with not that many people but they pass the virus on to almost all of them, whilst others have had wide contacts without infecting anyone .......
The average age of Covid deaths is 82 ish and the average life expectancy anyway is 81. In case you are wondering I am 68, with enough of a heart problem to be at risk of dying. I wouldn't mind isolating for however long it takes IF younger people could live their lives and find a little joy, instead of hiding in the shires like a set of hobbits.
The virus is still going to exist however long we are locked down. Tell Australians about how well fire breaks work when the wind blows. But that doesn't mean we shouldn't be sensible.
What is the UK operational false positive rate?
The UK operational false positive rate is unknown. There are no published studies on the operational false positive rate of any national COVID-19 testing programme.
An attempt has been made to estimate the likely false-positive rate of national COVID-19 testing programmes by examining data from published external quality assessments (EQAs) for RT-PCR assays for other RNA viruses carried out between 2004-2019 [7]. Results of 43 EQAs were examined, giving a median false positive rate of 2.3% (interquartile range 0.8-4.0%).
Why are false positives a problem?
DHSC figures show that 100,664 tests were carried out on 31 May 2020. 1,570 of those tests were positive for SARS-CoV-2 (1.6%). The majority of people tested on that day did not have SARS-CoV-2 (98.4% of tests are negative). When only a small proportion of people being tested have the virus, the operational false positive rate becomes very important. Clearly the false positive rate cannot exceed 1.6% on that day, and is likely to be much lower. If the operational false positive rate was 0.4%, 400 of the 1,570 positive tests would be false positives. That would represent 400 people being isolated when they are well, and much wasted effort in contact tracing. It is possible that a proportion of infections that we currently view as asymptomatic may in fact be due to these false positives. Unless we understand the operational false positive rate of the UK’s RT-PCR testing system we risk overestimating the COVID-19 incidence, the demand on track and trace, and the extent of asymptomatic infection.
Back to me - all kinds of bits of old virus apparently give a false positive. If the data is inaccurate the conclusions are going to be dubious. Maybe that's why the best we come up with is the Eyam approach to the Plague.
For all the science, tests don't differentiate between infected and infectious. So TheoLuddite on here may be right to talk about superspreaders, because evidence we do have is that whilst some infected people come into contact with not that many people but they pass the virus on to almost all of them, whilst others have had wide contacts without infecting anyone .......
The average age of Covid deaths is 82 ish and the average life expectancy anyway is 81. In case you are wondering I am 68, with enough of a heart problem to be at risk of dying. I wouldn't mind isolating for however long it takes IF younger people could live their lives and find a little joy, instead of hiding in the shires like a set of hobbits.
The virus is still going to exist however long we are locked down. Tell Australians about how well fire breaks work when the wind blows. But that doesn't mean we shouldn't be sensible.