Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what proportion of tests for covid-19 are false negatives.

False-negative (and true-positive) results are more likely to occur when disease prevalence is high, which is typically at the height of a pandemic or spike in infection. False-positive (and true-negative) results are more likely to occur when disease prevalence is low, which is generally at the beginning and end of a pandemic or a spike in infection rate.

The SARS-CoV-2 RNA tests (PCR is one such example) we are using are very accurate. Where the primer and probe sequences (which is identical to a part of the virus’ genetic code) are detected then the viral RNA is present. The analytical sensitivity is nearly 100%.