Carbonated Beverages and Citrus Juice Lead to Inaccurate Results in Quick COVID-19 Tests

When utilized correctly, COVID-19 lateral flow tests demonstrate high accuracy and specificity. However, the introduction of acidic fluids can lead to the antibodies in the tests clumping, potentially resulting in a false positive indication.

Viral TikTok clips depicting adolescents manipulating rapid COVID-19 tests by inserting sodas and other acidic solutions into the test inlets are generating significant attention. This is particularly notable in the UK, where these readily accessible at-home tests are employed for routine screening of secondary school and college students, as well as teachers. Although PCR tests are considered the primary method for detecting SARS-CoV-2, rapid COVID-19 tests use lateral flow technology and provide results in 30 minutes or less.

Fast Tests and the Student´s Tricks

These fast tests are not only quick but can also be done anywhere, making it easier for people to get tested. However, a study on July 5th, shared on the medRxiv server before official publication, found that certain drinks can make these tests show a wrong positive result. In the UK, if someone gets a positive result on a fast test, they have to be isolated for up to 10 days, tell authorities, and take a more detailed PCR test. If not, they might be fined. Education leaders in the UK are worried that some students might use false positive results to avoid going to school. Geoff Barton, the head of the Association of School and College Leaders in the UK, says that only a very small number of students are doing this.

The Current Credibility of the Tests

The recent increase in videos showing how to trick rapid tests has made the worries about their accuracy even bigger. Alexander Edwards, who works on creating medical tests at the University of Reading School of Pharmacy in the UK, says that some people are now thinking these tests are not reliable.

The Scientist interviewed Edwards to grasp the reasons behind how sodas can result in false positives and the wider consequences of manipulating these tests. Additionally, he explained why these tests shouldn’t be dismissed as ineffective.

A Lateral Flow Test 

is a quick way to check for a specific thing, like a virus, in a mixture. It works by using special parts that stick to the thing you’re looking for. If that thing is there, you see a line that shows it’s positive. It’s like a simple and fast test you can do to find out if something specific is in a sample.

How Accurate are they?

The accuracy of lateral flow tests can vary. They are generally considered quick and convenient, but they may have a higher chance of giving false results compared to more complex laboratory tests like PCR. The accuracy depends on factors such as the specific test kit used, how well the test is performed, and when it is used (for example, they may be more accurate when a person has higher viral loads).

In situations where a rapid result is crucial, such as initial screening or detecting outbreaks quickly, lateral flow tests can be valuable. However, if a more precise result is needed, especially for confirming an infection, a follow-up PCR test is often recommended. It’s important to follow the instructions carefully when using these tests to maximize their accuracy.

Lateral flow tests are a quick way to check for specific things, like viruses, in mixtures. They work by using special parts called antibodies that stick to the target. If the target is present, a visible line shows a positive result. However, the accuracy of these tests can vary, and adding things like strong acids can mess up the results. It’s important to follow instructions carefully and, for more precise results, confirm with a PCR test if needed.

Why could False Positives, whether Deliberate or Accidental, be a Cause for Worry?

False positives, whether intentional or accidental, can be a significant concern in testing programs, especially when screening asymptomatic individuals. Each false positive result requires the person and their contacts to be treated as if they have a highly contagious disease, which is often a legal requirement due to the perceived danger of the pathogen. Such instances, particularly if stemming from improper test use, not only affect individuals but also damage the public health system designed to protect the community.

How can we Reduce the Effect of False Positives?

The advice is pretty simple. Just try your best to do the test exactly how the instructions say. The reason is, when we have information we can trust about the test, it’s always from following the instructions provided by the maker. Even if you think you could do the test a different way and it would still be okay, we don’t have proof of that.

It might sound a bit dull to just stick to the instructions, but because it’s a medical test, it’s super important to do it the right way. If people start doing it differently, the whole system can go wrong.

Read the Original Article: The Scientist

Read more: The Emergence of JN.1: A New COVID-19 Variant and its Implications