Herpes Simplex Virus -1 and -2 Past Infection Blood Test

Herpes is a common virus that has two forms — HSV-1 and HSV-2. Most people with herpes don’t have any symptoms, but it can cause cold sores (oral herpes) and painful blisters around the genitals (genital herpes). After infection, symptoms usually show up within two weeks, but it can take months or years for symptoms to develop. 

Herpes sores usually heal in a few weeks, but there is no cure and the virus stays in the body, often causing repeat outbreaks. Over time, flare-ups tend to reduce in frequency and severity. 

HSV-1 usually causes oral herpes (cold sores). It’s usually spread by non-sexual contact with saliva from a person who has an HSV-1 infection (for example, by sharing cups or towels). HSV-1 can also cause genital herpes. Roughly 70% of the global population is infected with HSV-1, which is usually picked up during childhood, but not everyone who has it gets cold sores. 

HSV -2 is the most common cause of genital herpes, which is a sexually transmitted infection (STI). It’s possible to catch genital herpes from someone even if they don’t have symptoms. HSV-2 can also spread to the mouth and cause oral herpes. HSV-2 is widespread and thought to affect over 10% of people in the UK. It tends to cause more frequent flare-ups of herpes than HSV-1. 

With our blood test, you can find out whether you have antibodies against HSV — this tells you whether you’ve been exposed to and carry the infection, and if so, which type. While both HSV-1 and HSV-2 can cause genital herpes, HSV-2 is likely to result in more frequent flare-ups than HSV-1, so testing may help you learn what to expect. 

This test is unlikely to detect a current, first-time herpes infection as it takes time for antibodies to develop. If you do have symptoms of herpes, it’s important to attend a sexual health clinic as soon as possible for a diagnosis. In some cases, you may be offered treatment too. 

Provided the test is taken correctly, our Herpes Simplex Virus-1 and -2 Past Infection Blood Test is very accurate. Based on studies carried out by the assay manufacturer, this test was able to correctly detect all samples where HSV-1 antibodies were present (23 out of 81 samples) and all samples where HSV-2 antibodies were present (21 out of 82 samples).

The ability of this test to accurately detect HSV antibodies (true-positives) is known as its sensitivity, while its ability to detect true-negative results is known as its specificity. So, the results of these studies correspond to a clinical sensitivity and specificity of 100%.

Even with highly accurate tests, it’s still possible to receive a false-positive or false-negative result.

Genital herpes typically causes small blisters or sores around the genitals and anus. The blisters are usually red, swollen, and painful, and may burst to leave small, open sores or ulcers. If you notice any sores around your genitals, it’s important to attend a sexual health clinic as soon as you can.

Not everyone with genital herpes will have visible symptoms and the virus can still be transmitted even when sores aren’t present — this is known as asymptomatic shedding.

Yes, it’s possible to contract genital herpes from a cold sore if there’s direct contact with a cold sore during oral sex. To reduce the risk of transmission, it’s important to avoid oral sex or close genital contact if you or your partner have an active cold sore.

Using condoms can also lower the risk, although it's not always 100% effective because herpes can be spread from skin-to-skin contact outside the area covered by the condom.

Genital herpes is a common condition in the UK. However, exact figures are difficult to determine since many people with the virus may not have symptoms or may not seek a medical diagnosis.

In 2022, there were nearly 25,000 new cases of genital herpes diagnosed in the UK, making up over 6% of all new STI diagnoses.

Individuals most at risk of contracting genital herpes include:

-Women — women are almost twice as likely to contract genital herpes as men

-Young adults — peak incidence of HSV is in people aged 15–24

-People with multiple partners

-People who have unprotected sex

-Men who have sex with men (MSM)

-People with HIV or a weakened immune system

-People with a partner who has had previous genital herpes