There is such a small amount of HIV in the saliva of a person with HIV that the infection can’t be passed on from kissing. But lots of people find it confusing that you can use oral samples to test for HIV.

To explain this, the first thing to know is that oral HIV tests do not detect the virus itself, instead they look for ‘antibodies’. These are cells that the immune system develops to respond to an HIV infection. So, oral fluids don’t contain the virus needed to pass HIV on, but they do contain the antibodies required to detect an HIV infection.

It’s also worth noting that the tests do not look for antibodies in saliva, instead they test something called ‘oral mucosal transudate’, which is a fluid that is released from the cells that make up your cheeks and gums. This is why when you take an oral sample you rub the stick along your gums and cheeks, where antibodies are more likely to be found.

Although it is now recommended that countries everywhere provide self-testing as an option, the self-testing kits are not available everywhere. 

Whether or not the tests are available for you can also depend on whether the clinic you live near stocks them. 

To find out whether there are self-testing kits available near you ask a healthcare worker.

As long as the person testing is past the window period, self-tests are just as accurate as laboratory testing at detecting negative results. Oral self-tests are 99.9% accurate for negative results. This means that so long as the window period has passed and the test is used correctly, oral tests are very unlikely to give a false negative result (telling a person that they don't have HIV if, in fact, they do).

Self-tests are slightly more likely to give false positives than normal laboratory tests. This is why it is advised that all positive results are double-checked in a clinic. Once double-checked you can know that the result is accurate and get the care that you need.