AQW 9931/17-22

Ms Claire Sugden
Independent
East Londonderry

Tabled Date: 09/11/2020
Answered On Date: 11/12/2020
Priority Written: No

Question:
To ask the Minister of Health what are the rates of (i) false positive COVID-19 tests; and (ii) inconclusive tests, broken down by 10-year age ranges.

Answer:

Given the different testing platforms and kits that are in use for SARS-CoV2 testing, it is not possible to ascertain accurate overall false positive test rates.

To prevent the reporting of false positives, the laboratory will assess all positives using criteria that may indicate a false positive may be occurring. This criteria includes:

If only 1 gene target out of 2 or 3 gene targets are positive

Weak Ct values (viral load) close to the limit of detection

When these indicators occur repeat testing or testing the sample on a different platform with a different specificity profile is undertaken. This confirmatory testing clarifies the result in most cases.

Inconclusive test rates are recorded in the Covid-19 Daily Dashboard, at page 6. I have included a link below for your convenience.

https://www.health-ni.gov.uk/articles/covid-19-daily-dashboard-updates