The State’s medical devices regulator says it is examining reports of false positives from one of the most commonly used rapid antigen tests for Covid-19.
The Health Products Regulatory Agency (HPRA) says it has received a number of reports from medical professionals and members of the public over the performance of the Genrui antigen test.
The agency says it is following up with the manufacturer of the test to investigate the matter and will also liaise with other European competent authorities in relation to this issue.
Received 100s of messages through my Insta about Genrui antigen tests.
— Dr Niamh Ni Loinsigh (@niamh_dr) January 1, 2022
When pcr was available there seemed to have been lots of false positives with these kits.
This could have major implications for people now with no pcr available.
Have you had any issues with them? pic.twitter.com/hmMgGz8hFp
Hospital Report
The Genrui brand is one of the cheapest and most popular rapid antigen test brands, and is sold in supermarkets such as Dunnes Stores and Lidl.
Large numbers of people have taken to social media in recent days to say their positive result using the Genrui test was not confirmed when they went for a PCR test.
Paediatrician Dr Niamh Lynch said she received "hundreds" of messages when she raised the issue on her Instagram account.
She said it appears there have been “lots” of false positives with these test kits, and warned this could have “major implications” now that antigen kits have a greater role in the testing system.
GP Darach Ó Ciardha said his work had been “substantially curtailed” due to false positives involving patients using the Genrui tests.
Stephen McMahon of the Irish Patients’ Association said people who had made contact on the issue were “p***ed off” to find their PCR test was negative after their antigen result had been positive. This had “upended all sorts of things” for many people over the holiday period, he said.
The patient group intends to write to Dunnes Stores over its sale of the Genrui kits, he added.
Genrui kits can be used for self-testing by people aged 18 to 75 years, according to the product leaflet.
‘Faint’ lines
The leaflet advises users to “look very closely” at the results along the control and test lines on the kit, as a T (ie test) line result can be very faint. “Any pink/purple here [on the T line] indicates a positive result.”
Anyone who tests positive on an antigen test is advised to self-isolate pending a confirmatory PCR test. However, due to soaring Covid-19 case numbers, the PCR testing system is currently overloaded and many people are having to wait days for a PCR test.
The HPRA says anyone who receives a positive result from an antigen test should follow current public health advice on self-isolation and follow-up PCR testing.
A spokeswoman added: “It is widely acknowledged that antigen tests are less accurate than PCR tests and so must be used in line with current public health guidance. Antigen tests, like all diagnostics, have the potential to provide false negative and false positive results.”
According to the product leaflet, a test of 100 samples using the Genrui kit resulted in zero false positives, giving a specificity of 100 per cent.
Under EU directives, medical tests must be CE marked to be placed on the European market. Once they are certified by a competent body in any member state, they can be sold across the EU.
The Genrui kits are marked CE1434, indicating they were certified by the Polish Centre for Testing and Certification (PCTC).
Genrui and the PCTC have been asked to comment on the issues raised in this article.
