The number of negative PCR tests booked as a result of a positive lateral flow tests have been questioned in Tynwald.

Jason Moorhouse MHK asked the Minister for Health and Social Care, Lawrie Hooper: ’How many people received in the last 30 days a negative result from a PCR test which was booked as a consequence of a positive lateral flow test (LFT) result?’

The question came after Castletown resident Jason Scales and another constituent raised the issue.

In response, Mr Hooper confirmed that, between November 7 and December 6, there were 2,224 PCR tests conducted on the island as a consequence of a positive LFT.

Of these, 2,000 were confirmed positives and 224 were confirmed negatives.

Mr Moorhouse, who represents Arbory, Castletown and Malew, then questioned the 224 negative results, in light of the fact that these PCR tests were booked as a result of a positive test result.

He said: ’Presumably some of the 224 people who received negative test results after they had a positive LFT test result have come back and raised concerns.

’Were any of them offered subsequent PCR tests? And were any of them found to have positive results?’

In response, Mr Hooper said: ’No test is perfect. No test is 100% reliable.

’We do know that the RT-PCR (Real Time Polymerase Chain Reaction) test is close to 100% specific, but when testing something in the region of 140,000 or more swabs, there will be occasions when an incorrect result is issued.

’Currently at present it seems that lateral flows have an accuracy of around about 90% on the Isle of Man, and so the general understanding is the PCR will confirm what is already detected on a lateral flow, and then any unexpected result can sometimes be concerning for the individual.’

He added: ’But there are a lot of reasons why you may have a positive lateral flow, and a negative PCR.

’A common reason is simply the number of people being tested. We’re using at the moment in the region of around about 40,000 LFTs a week. As a result of this, it’s clear from the numbers we’ve already talked about, that around about 160 people a week will get a false positive and report this to the 111 team. These people will then test negative on the PCR.

’There are a lot of other factors that can result in affecting the test results, including the swabbing technique, the time of collection, multiple swabbing, viral load [and] the immune stage of the individual, and so it is difficult to draw any meaningful comparisons or conclusions from these issues.

’My understanding is that because people testing positive on a lateral flow and then subsequently negative on a PCR is an entirely expected event, it is not something that we are surprised to see, because the numbers are very small, actually there are no second tests being offered to people as far as I’m aware.’