Positive results from UK single gene testing for SARS-COV-2 may be inconclusive, negative or detecting past infections

TL;DR

This paper discusses the limitations of UK SARS-CoV-2 testing, highlighting that positive results based on a single gene target may be inconclusive, negative, or indicative of past infection, due to lack of diagnostic validation.

Contribution

It critically evaluates the reliability of single gene target positive results in SARS-CoV-2 testing without confirmatory validation.

Findings

Many positive results may be inconclusive or from past infections

Single gene detection may not reliably indicate current infection

Diagnostic validation is essential for accurate interpretation

Abstract

The UK Office for National Statistics (ONS) publish a regular infection survey that reports data on positive RT-PCR test results for SARS-COV-2 virus. This survey reports that a large proportion of positive test results may be based on the detection of a single target gene rather than on two or more target genes as required in the manufacturer instructions for use, and by the WHO in their emergency use assessment. Without diagnostic validation, for both the original virus and any variants, it is not clear what can be concluded from a positive test resulting from a single target gene call, especially if there was no confirmatory testing. Given this, many of the reported positive results may be inconclusive, negative or from people who suffered past infection for SARS-COV-2.