Operation Moonshot: rapid Covid test missed over 50% of cases in pilot

[Northerner]

A rapid coronavirus test at the heart of Boris Johnson’s mass-testing strategy missed more than 50% of positive cases in an Operation Moonshot pilot in Greater Manchester, the Guardian can reveal.

The 20-minute tests, on which the government has spent £323m for use with hospital and care home staff with no symptoms, identified only 46.7% of infections during a crucial trial in Manchester and Salford last month.

This means that many of those carrying Covid-19 were wrongly told they were free of the virus, potentially allowing them to infect others.

The test had been due to be used in the UK’s first city-wide mass-testing initiative, which starts in Liverpool on Friday. However, on Thursday night a council spokesman said it would no longer be deployed as part of the trial.

The government said earlier on Thursday that the test would be used on symptomless NHS staff in the city, but that was denied by a Liverpool council spokesman, who said it would “not be used as part of the pilot”. He said the council was looking to use the test at a later date but that it would not feature in the mass-screening programme.

Operation Moonshot: rapid Covid test missed over 50% of cases in pilot

Exclusive: mass-testing experts say tests should not be widely used in hospitals or care homes

www.theguardian.com

 

[novonord]

would have thought a test that picks up more than half the asymptomatic cases, some of whom have very little virus at all in their nasopharynx /saliva, is better than nothing particularly when applied to health workers, the question is how many false positives were there, suspect this is a very small number.

 

[Bruce Stephens]

would have thought a test that picks up more than half the asymptomatic cases, some of whom have very little virus at all in their nasopharynx /saliva, is better than nothing particularly when applied to health workers, the question is how many false positives were there, suspect this is a very small number.

As always, depends what the tests are being used for. If you're trying to find likely infectious people then it looks really useful: missing some infected people who aren't shedding so much virus is probably a good thing. If you're trying to find people who are definitely not infectious (trying to screen health workers or something) then it's probably less good.

Would seem like something that the UK's public health/screening groups could be involved with, to gain best value from using these things.

 

[grovesy]

As always, depends what the tests are being used for. If you're trying to find likely infectious people then it looks really useful: missing some infected people who aren't shedding so much virus is probably a good thing. If you're trying to find people who are definitely not infectious (trying to screen health workers or something) then it's probably less good.

Would seem like something that the UK's public health/screening groups could be involved with, to gain best value from using these things.

My thoughts from what I have heard been said by the politicans is they are hoping for these test to allow those who are negative as assurance they can go on and get on with things. The pilot is only for a fortnight and to me that is not that long.

 

[Bruce Stephens]

My thoughts from what I have heard been said by the politicans is they are hoping for these test to allow those who are negative as assurance they can go on and get on with things.

That doesn't seem silly to me. If you get a negative on such a test you're probably not very infectious, so sure. (Back in March there was modelling suggesting such an approach could work (together with isolating if you're positive) on its own: you just need to test the whole population every couple of weeks, and the test has to not suck very badly.)

They've said they want to roll this out more widely if it's successful. Have they given any indication at all about what "successful" means?

 

[grovesy]

That doesn't seem silly to me. If you get a negative on such a test you're probably not very infectious, so sure. (Back in March there was modelling suggesting such an approach could work (together with isolating if you're positive) on its own: you just need to test the whole population every couple of weeks, and the test has to not suck very badly.)

They've said they want to roll this out more widely if it's successful. Have they given any indication at all about what "successful" means?

Not that I am aware of it was answer to question in commons that the trail was 2 weeks.

 

[Bruce Stephens]

Not that I am aware of it was answer to question in commons that the trail was 2 weeks.

I just read a few stories about it and couldn't see anything specific. I presume it'll be a success if they find enough people who test positive who wouldn't otherwise have sought (or been eligible for) a test, and if it seems like the practicalities can be resolved.