Test for Genital Herpes

The best way to test for genital herpes is to swab a blister and have the sample analysed at a laboratory. Often, the infection is diagnosed based on the symptoms and the appearance of the blisters.

If you think you may have herpes, you can see your GP or visit a sexual health clinic for a test. Patients who prefer an anonymous test can get diagnosed using our extended STI test kit, which includes a test for genital herpes.

If you suspect that you’ve been infected with the herpes simplex virus and have symptoms, getting tested is the only way to confirm whether you have herpes. The virus can cause an outbreak weeks, months or years after it first entered your body. If you are currently experiencing your first outbreak, your current partner does not necessarily have to be the cause of your infection.

You may want to get tested if your partner has genital herpes, if you’ve had unprotected sex with a new partner, or if you have another STI – because STIs are often transmitted together. Also, pregnant women who think they could have the virus should also get tested.

Swab tests and urine tests can only diagnose herpes if there are open sores or blisters. If you think you might have been exposed to herpes in the past but don’t have any symptoms, these tests won’t tell you if you have herpes. There are blood tests available that can check if you have been exposed to herpes before.

Because the herpes virus is so common, most people wouldn’t need to have this blood test – if you’ve never had symptoms it’s likely that you won’t ever develop symptoms, and there’s no treatment or way to predict if you will have an outbreak anyway. It might be helpful for people who have a partner who is known to have herpes, because they can find out if they already have the virus too.

A common test for genital herpes is the swab test, which consists of taking a tissue sample from the sores (of the liquid inside them) and creating a viral culture in a lab. It takes a couple of days for the culture to grow. Laboratories usually send the test result within 1-2 weeks.

Another method used for diagnosing genital herpes is a blood test. The analysis of a blood sample shows whether you have herpes antibodies. If you have herpes antibodies, this means that you have been infected with the virus at some point. There is also a DNA test (which relies on blood or infected tissue) which can help determine which type of herpes virus you carry – HSV1 or HSV2.

The problem with the swab test is that it is only 50% to 90% reliable. This means, that for half of the infected patients, the test may come back negative (while they are in fact positive). The accuracy of the swab test depends on the quality of the sample taken. In many cases, the blisters do not contain enough fluid to start a viral culture. Samples from a primary outbreak tend to be more reliable than those from a recurrent outbreak because the blisters contain more fluid during the first outbreak.

Blood tests are not 100% reliable either but they provide a more accurate result. Blood tests are usually recommended for people who have a high risk of genital herpes (for example, if they have a partner who is known to have genital herpes).

If you see your GP or visit a GUM clinic, they will ask a number of questions about your condition before providing a diagnosis. Your doctor will most likely ask you about your symptoms, recent sexual encounters, your STI history, whether you use condoms and whether you are taking any medication. You should use your consultation to ask any questions you may have with regards to your condition, your risk of STIs and how to avoid infecting future partners.

Genital herpes is a very common STI, and the most common way to diagnose it is in fact to simply examine your symptoms. GPs and doctors specialized in skin diseases or genital organs can diagnose whether your blisters are typical for genital herpes or not. If you’re not sure whether you have genital herpes, you can check our page on the signs of genital herpes or take our free photo assessment. Our doctors will reply within 24 hours (during weekdays).