A: The fact that there are so many different types of ATK tests means that we must first assess their safety. In all cases, any test should only be used according to its specific instructions.
First of all, many people have seen doctors or nurses perform deep nasal swabs in hospitals or clinics. However, this is not recommended for home use because the depth to which they go is carefully managed. Some reach the back of the nasal cavity and the very back of the throat. This could be very dangerous if performed at home where those administering the test do not have the relevant expertise. This is especially the case for testing children, who may fidget, flinch, or resist during testing, which can place them in danger of injury.
For home use, and especially for children, the nasal swabs are still the best because they can be used to test any age. Most of them require you to swab the nostril region using a rotating motion. Some people believe that you can use mucus from blowing their nose but this is not correct because the tests require cells from the nasal cavity. Therefore, it is necessary to swab that area to ensure those cells are gathered and the test is valid. Only testing mucus increases the chance of an invalid test.
Recent studies have found saliva tests to be more convenient as no intrusive swabbing is required and they can be easily done at home using the saliva of the person being tested. However, the test instructions advise that the saliva should be egested into a small bowl, which requires the individual to be able to produce that phlegm from the back of their throat. As such, this may not be suitable for younger children.
In addition, devices which are held in the mouth during testing are not as effective as those that rely on saliva egested from the throat because they may not include tissue cells. Although there is emerging evidence that Omicron is more prevalent in the throat, it is important to understand that testing the throat and testing saliva are not one and the same thing. Throat swabs are distinct from saliva tests.
There is a belief that more of the virus is found when screening saliva but this is unconfirmed. However, the virus is found when swabbing the throat, which is what is used during PCR testing at hospital, where they use two swabs: one for the throat and one for the nasal cavity - neither of which are saliva-based. For home use though, throat swabs are not recommended.