Innova lateral flow test produces false positives.

The Innova lateral flow rapid covid test was designed to identify people who are shedding high levels of virus. They have been criticized for giving people a false sense of security, since they have a high false negative rate. Innova initially tried to sell them in the US, but never applied to the FDA for EUA. The FDA responded with a warning and a recall. So they are not currently being sold in the US.

However, in the UK, the Innova rapid tests have been used by schools to try to cut down on the spread of the virus on the theory that they would at least remove students shedding high levels of virus from the general population. Students were required to test twice a week, and were given the tests to take at home.

When used as directed, the false positive rate for these tests is very low. However, some enterprising young people read the instructions, which told them not to eat or drink anything due to the risk of a false positive, and decided to experiment. This led to the discovery by the students that they could get a false positive and excuse to stay home from school by applying various soft drinks rather than their swabbed sample to the test cassette. This led to sharing this information on social media, which led to investigation by the grownups.

It turns out that many soft drinks, including Coke, diet Coke, and Sprite, will produce false positives in these tests.

I'm going to call this one a win for the grownups, and a loss for the kids and Innova.

Link to study:
https://www.medrxiv.org/content/10.1101/2021.07.05.21260003v1.full.pdf

FDA recall:
https://www.fda.gov/medical-devices/safety-communications/stop-using-innova-medical-group-sars-cov-2-antigen-rapid-qualitative-test-fda-safety-communication