Are HIV tests conclusive?

Answer

Dear Lina,

Thank you for your question.

I’ll start with the good news. So if you had a negative test 6.5 months after the last sexual contact, you can sleep on both ears. After all, a classic fourth-generation HIV test (the most recent, and used in the various laboratories) on a blood sample gives a reliable test result four weeks after the last risk contact.

A test marks your HIV status at the time of sampling. So if your doctor takes a blood sample and sends this sample to the laboratory, where the HIV test is negative, you are effectively HIV negative. It does not matter how many times in the past you have had sex without a condom (if the last risk was at least four weeks earlier).

However, if you search online, you will also find other reference periods (3 months to even 6 months). This has to do with several characteristics of the test:

• Earlier generations of HIV tests: Older tests were less likely to give a reliable result. Because not every administrator of every website is aware of the latest technology, or because documents are outdated, you sometimes come across a different reference period;
• Rapid test and/or self-test: as with a corona test, there is also a rapid test for HIV. A rapid test refers to a ‘quick result’, not to ‘taking a test soon after the risk contact’. However, this rapid test does not use the same technology, and therefore does not give a reliable result as quickly;
• Saliva sample instead of a blood sample: you will find (for specific groups) testing strategies that use saliva samples. These are easier to collect and are sometimes collected in non-medical settings (nightlife). However, saliva samples cannot be tested with the same technology, and are therefore less likely to give a reliable result.

However, I also want to add a nuance. After all, sexual contact not only puts you at risk of contracting HIV, but also other sexually transmitted infections (STIs). The most common STIs in Belgium are chlamydia (9294 diagnoses in 2018), gonorrhea (2822 diagnoses in 2018) and syphilis (1901 diagnoses in 2018). The most recent figures we have are from 2018.

These STIs do not always give rise to physical complaints (symptoms), but in exceptional cases can lead to serious complications. It is therefore best to take an STI test regularly if you have different sexual partners. Your doctor can easily administer this test, and with this you take care of your own health.

Regards,

Tom Platteau