Retention of DNA material from PCR swabs (FOI)

Request

Concerning DNA material from PCR Swabs

I am referring to a previous response published at the following link:

DNA material from PCR swabs (FOI)

Why do you need to keep the DNA material collected from the PCR swab tests in order to:

a) Verify kit batches are working properly (as per a previous response by the FOI)

b) Determine if new types of assays are suitable for use (as per a previous response by the FOI) Can you also please describe precisely what is meant by sequencing (as described in a previous FOI at the link above) and the importance of it which warrants the retrieval of <5% of the one's DNA. (I obtained that number from a previous response on the FOI).

Furthermore, under what law are you able to keep the DNA from the PCR swabs without any prior consent from the person taking the test?

Response

It is the viral genome that is targeted. So in the case of COVID, which is an RNA virus, it is the RNA of the virus that is sought and analysed. The test measures the amount of COVID RNA present in the swab sample.

The original question referred to DNA. The response referred to viral genetic material in general and DNA was not mentioned in the response. The above should clarify.

As stated in the first response >95% of the swabs are destroyed by autoclaving. Less than 5% of viral genomic material is retained for quality purposes.

Under Human tissue Authority (HTA) guidance, consent for this testing of the virus genome is given by patients when they allow the swab to be taken.

It is a requirement of ISO152189, the international standard with which all Pathology laboratories must comply, that all new batches of testing reagents be tested to check that they are working correctly before they are used for patient testing. This requires testing with known negative and positive previous samples to confirm that the test is working correctly.

This is to eliminate the risk that in the transport from manufacturer to laboratory there was any damage to these reagents making them unfit for use, or that any manufacturing effects have in some way affected the overall performance of the assay reagents when used for testing patient samples.

In order to increase the Island’s capacity for Covid testing, and to be sure we are using the best most accurate and up to date methods for that testing, it is necessary, in line with ISO15189, the international standard that governs laboratory testing to confirm that any potential new assay works as the manufacturers documentation claims that it does, before we deploy any new test option into our testing regimes for the Island.

Part of that confirmation is to test any new testing assay with known positive and negative samples to confirm the correct responsiveness of the test and that it will be safe to use for patient testing.

Sequencing is specialist testing of the viral genome, in this case viral RNA, to characterise this fully. Different COVID mutations of the virus will have slightly different sequences in the makeup of their RNA.

This allows the laboratory to ascertain if new variants have emerged eg the new UK or the South African variants. It is not a sequencing of patient DNA but of viral RNA.

This testing is vital in the efforts to manage public health on the Island and to inform Government decisions around the public health management of the pandemic.

As stated above the first thing to be clear about is that we are seeking presence or absence of viral genome.

Secondly it is a requirement of safe laboratory practice, in line with the ISO15189 international standards to which the laboratory is expected to adhere, that new batches of reagents for tests are checked with positive and negative material before putting in to use for patient testing.

Human Tissue Authority guidance is that initial consent for the testing is given by the patient consent to have the swab taken. The guidance also states that further consent for the use of samples is not required for samples used for Public Health monitoring or for quality assurance purposes.