Why Are Some Lateral Flow Tests Nose-Only?

As the pandemic got more serious, health officials were on their toes trying to figure out the virus. The specimens came from the sputum, the back of the throat or the nose. It wasn't until a short while later that the CDC stated that only the nasopharyngeal test was necessary, that is, a specimen from the nasal passage. 

Regarding ease, getting the specimen from your throat is not the most pleasant experience, so the lateral flow test nose only is preferred.

Given that it is necessary for key health workers, students and parents to take the tests at least twice a week, the nose-only lateral flow test is a much better option. Thankfully, buying lateral flow test kits is easy these days as brands like the Healgen test and the FlowFlex COVID-19 test are available online.     

The Features of Nose-Only Lateral Flow Tests

Because of the comfort and how simple nose-only tests are, many people go for the option, but what are some of its features and how does it compare to the other tests? 

In terms of the CE approval, both have approval. When it comes to specificity, which means that the ability of a test does not produce a false positive, the nasopharyngeal test is the winner. There is a 0.4% chance that the result might be a false positive, whereas, for the nasal kit, it has a 0.5% chance. Even though the gap looks small, it can make a difference.

How the Lateral Flow Nose-Only Tests Work

Using a swab, you obtain a sample from your nose. Ensure you go deep inside, at least 3 cm in, until you feel resistance, then roll it around a couple of times. Repeat this for the other nose as well. You then dip it in an extraction solution; once extracted, you place it on a lateral flow test pad. The results will be ready in the next 15 minutes or 30; this depends on the type and brand of test you are using. Unlike other tests, when doing a lateral flow test, you don't need to send your sample back to the lab.

Interpretation is also relatively easy; if one line is next to the control line (C-line), the result is negative. However, if there are lines on both the Test line(T-line) and the control line, then the result is positive. The result can also be invalid; in this case, there are no lines, or there is a line next to T; this usually means the test is invalid; hence you will have to retake it. When retaking the test, follow the instructions carefully to get accurate results.         

The Benefits of Nose-Only Lateral Flow Tests

Several benefits come with the nose-only test. The first one is although most people consider it uncomfortable, the throat test is even more uncomfortable, making the nose-only test look at least favourable.

In terms of specificity, the nose-only test is less likely to produce a false positive as they have higher specificity. They are also reliable in terms of sensitivity as it detects a high viral load.  

Conclusion

The differences between the various type of tests are minimal. Both work and get the job done, but they involve different routes. For a slightly less-unpleasant experience, the nose-only option is the go-to for many, which is why it is common.