Herpes is one of the most common STDs in the US. According to the CDC, one in every six people between ages 14 and 49 have genital herpes.
Most of them have no idea they have it since the infection is often asymptomatic.
If you are concerned that you may have herpes, the obvious next step is to get tested. But not so fast.
Testing for herpes is not as straightforward as testing for other STDs like chlamydia and gonorrhea.
Accuracy for some tests is questionable, and certain tests are not recommended at all if you have no symptoms.
Here’s what doctors say about herpes tests and their accuracy.
Blood Tests are Inconclusive
There are two types of blood tests for herpes: IgM and IgG.
Both these tests look for antibodies the body produces to fight the herpes virus. They don’t look for the virus itself.
Of these two tests, IgG is the most common, and the one experts recommend.
Serious issues plague IgM: it produces a high rate of false results, it doesn’t tell you when infection occurred, it cannot distinguish between the two types of herpes viruses (HSV-1 and HSV-2), and it sometimes confuses herpes with other related viruses.
If you get a positive result from an IgM test, you have no idea what kind of herpes you have. For all you know, it’s HSV-1, which almost every adult in the US has from their childhood (it’s typically passed via non-sexual means through saliva).
The IgG can tell if you have HSV-1 or HSV-2.
However, for it to be accurate, there needs to be detectable levels of antibodies in the blood. Different people with herpes take varying periods to build these antibodies to the level required for the test – a few weeks for some months for others.
So you could easily get a false negative if you take the test too soon after exposure.
Another problem with blood tests, even those approved by the FDA, is that they cannot tell whether you have oral herpes or genital herpes.
No Symptoms, No Testing
Health experts have a simple piece of advice: if you do not have symptoms of herpes – usually a lesion or blister –don’t bother getting a blood test.
Not only are these tests inconclusive, but they can also leave you worried for nothing.
There’s a lot of stigma surrounding herpes. A positive test result may cause shame and guilt when it’s probably just HSV-1, a very very common type of herpes.
Even the CDC doesn’t recommend herpes screening for people without symptoms.
The Most Accurate Herpes Tests
If you’ve noticed a lesion or sore around your genitals, this is the best time to get a herpes test.
That’s because a healthcare provider can take a sample directly from the affected area and look directly for the virus rather than the antibodies.
The most common test is a culture test. It needs to be taken as soon as you notice a lesion.
If you wait too long and the lesion begins to heal, there may not be enough viruses for the culture to detect, and you might get a false negative.
If you get a positive result from a culture test, the chances of it being a false positive are very low. You most likely have herpes.
The culture can be analyzed to determine whether the viruses is HSV-1 or HSV-2.
Nucleic Acid Amplification Testing or NAAT is the more modern option. It’s fast and accurate. The test looks for the virus’s DNA.
The Bottom Line on Herpes Tests
Unless you are pregnant or you think you’ve contracted herpes from your partner, wait until you see actual symptoms to get tested.
A swab is taken from your genitals or wherever the lesion or sore occurs the most accurate way to test for herpes.
If you don’t want to go to the doctor, you can order an at-home Herpes test. It offers more privacy and convenience than going to the hospital or clinic.
If you get a positive result from an at-home test, it’s a good idea to go to the hospital for further testing to make sure it is not a false positive.