Contamination issues blamed for high level of false positives with Genrui antigen tests

Health Products Regulatory Authority highlights problems with two batches of the test

The Genrui antigen test was one of the most popular such tests on the Irish market.  Photograph: iStock
The Genrui antigen test was one of the most popular such tests on the Irish market. Photograph: iStock

Contamination issues have been blamed for a high level of false positives with a leading Covid-19 rapid antigen test.

More than 1,350 reports of false positives have been made by consumers to the Health Products Regulatory Authority (HPRA) in relation to the Genrui antigen test, the regulator said on Tuesday.

The regulator on Tuesday issued a safety notice to raise awareness of product recalls for two batches of the test, which has already been taken off the shelves of Irish retailers.

It says the manufacturer has identified an issue relating to contamination of the sample diluent for two specific batches sold here: 20211008 and 20211125. These batches are being recalled from affected retailers and members of the public.

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Earlier this month, the HPRA had said the Genrui tests should be removed from the shelves of retailers on a voluntary basis after the complaints about false positive results.

Retailers are now being advised to continue the voluntary suspension from sale of the Genrui self-test while the recall is ongoing.

“If members of the public have not already returned these self-tests under the voluntary removal from sale, they should immediately identify any Genrui self-tests in their possession with these batch numbers. These self-tests should not be used and can be returned to the retailer where they were purchased,” the HPRA stated.

Genrui has temporarily suspended the sale of its self-tests in Ireland on a voluntary basis while the recall is ongoing, the regulator added.

The HPRA says it is continuing to liaise with the manufacturer and will update the safety notice if further information becomes available.

EU experience

The Genrui test has been suspended from sale in Spain as a precautionary measure but, the HPRA says, other EU member states are not experiencing the same high number of reports of false positive results.

It says it has not received a high number of reports of false negatives or false positives for any other antigen tests.

Concerns about the product started over Christmas, when users noticed they were testing positive with it and then negative with the PCR test required at the time to confirm the initial result. Other people said they were testing positive with the Genrui kit but negative with other antigen test brands.

Some users reported getting a faint test line on the result but the Genrui instructions clearly say “any pink/purple here indicates a positive result”.

The kit was one of the most popular antigen test brands on the Irish market and was sold by Lidl and SuperValu among other retailers.

Paul Cullen

Paul Cullen

Paul Cullen is a former heath editor of The Irish Times.