新型コロナウィルス検査の３０％が偽陰性の可能性

英国も新型コロナウィルス検査の３０％が偽陰性の可能性と専門家。https://t.co/SkKRVeoM4R https://t.co/fY8tVS5cIn

— kazukazu88 (@kazukazu881) April 3, 2020

For one thing, PCR tests are labour-intensive and take some time to complete – which, as Professor Woodcock says, can leave patients “sat on wards without a firm position on their infectivity for 24 hours”.

And it’s not just waiting for the results. Both point to the issue of “false negatives” – where the test says a patient has not got coronavirus when in fact they have.

Professor Woodcock and Dr Gill both estimate that the rate of false negatives could be around 30 per cent.

Professor Woodcock suggests that these could be caused by “low levels of the virus in the early stages of the disease” or “especially poor technique in sampling or conducting the test”.

He describes the dangers of these “many” false negatives: “potentially infectious patients could be nursed in COVID negative areas, or sent home thinking they are non-infectious”.


Patients are being tested more than once
Some patients are receiving more than one coronavirus test in the course of a single day.

We can see this in figures tweeted out by Public Health England earlier in the week that show some 8,278 tests were carried out on one particular day on just 4,908 individuals.

The latest stats show 10,657 tests were carried out yesterday on 7,771 patients.

We don’t know exactly why each of these patients would have had the number of tests they did.

But as Professor Woodcock points out, if the current tests can only detect the presence of the virus 70 per cent of the time, “we have a lot of patients waiting for a repeat virus testing/diagnosis”.

ちなみに、偽陽性もあるだろうし。

陰性に関しては１００％の長崎大キャノン検査だね。