Stop Abusing Your COVID-19 Self-Test Kits With Tap Water To 'Prove' They're Faulty
Some Malaysians on social media have been using tap water as a sample on their COVID-19 self-test kits in an attempt to prove the kits are useless and faulty
In the viral videos, the home experimenters showed that their kits displayed 'positive' results after they dropped plain tap water into the sample wells of the kits.
Many of them claim that the health authorities and test kit manufacturers are conspiring against the public with ineffective detection kits.
However, many of the videos have also been taken down as netizens quickly discern between the truth and fake news
Several social media users pointed out that the test kit's buffer reagent was not used, and the two lines — indicating a positive result — appeared and was read almost immediately, instead of the usual wait of 15 minutes.
The issue has also been recently addressed by the country's Medical Device Authority (MDA), a regulatory body under the Ministry of Health (MOH) that approved the use of the medical device.
"Based on a two-minute video, the usage method shown does not follow the instructions as in the label and leaflet included in the test kit," they said in a statement on 10 February.
They reminded users to use the test kits in accordance with their intended purpose and instructions, otherwise they will likely produce misleading and pointless results.
The MDA said they are also concerned about the circulation of the video and will conduct an investigation to prevent further confusion among the public regarding the use of COVID-19 self-test kits.
But, why do the COVID-19 rapid test kits turn out positive with tap water anyway?
Well, for starters, the US Centers for Disease Control has assured the public that the COVID-19 virus is not transmissible in our water supplies.
So, the results obtained with tap water are definitely false positives.
The test kits produce the false positive results because — as explained by Abbott, a US manufacturer of COVID-19 self-test kits, in a fact-check interview with Reuters — using anything other than nasal secretions and the reagent included in the kit can throw off the antibodies that are laden on the strip.
This is backed up by a study published in the International Journal of Infectious Diseases in August 2021 that tested COVID-19 rapid test kits with soft drinks, energy drinks, alcoholic beverages, mineral water, and carbonated water.
"We observed that all [drinks] caused the appearance of a red test line," the authors wrote. "However, when equal volumes of the buffer and the respective beverages are mixed, there are no false positive test lines."
They said a likely explanation for the occurrence of the false positive test lines could be the altered pH in the solutions. In effect, it would interfere with the function of the antibodies that should be binding to COVID-19 virus particles instead.