What is a herpes (HSV) test?
Herpes is a skin infection caused by the herpes simplex virus, known as HSV. HSV causes painful blisters or sores in different parts of the body. There are two main types of HSV:
- HSV-1, which usually causes blisters or cold sores around the mouth (oral herpes)
- HSV-2, which usually causes blisters or sores in the genital area (genital herpes)
Herpes is spread through direct contact with sores. HSV-2 is usually spread through vaginal, oral, or anal sex. Sometimes herpes can be spread even if there are no visible sores.
Both HSV-1 and HSV-2 are recurring infections. That means after your first outbreak of sores clears up, you may get another outbreak in the future. But the severity and number of outbreaks tend to lessen over time. Although oral and genital herpes can be uncomfortable, the viruses usually don’t cause any major health problems.
In rare cases, HSV can infect other parts of the body, including the brain and spinal cord. These infections can be very serious. Herpes can also be dangerous to a newborn baby. A mother with herpes can pass the infection to her baby during delivery. A herpes infection can be life threatening to a baby.
An HSV test looks for the presence of the virus in your body. While there is no cure for herpes, there are medicines that can help manage the condition.
Other names: herpes culture, herpes simplex viral culture, HSV-1 antibodies, HSV-2 antibodies, HSV DNA
What is it used for?
An HSV test may be used to:
- Find out whether sores on the mouth or genitals are caused by HSV
- Diagnose an HSV infection in a pregnant woman
- Find out if a newborn is infected with HSV
Why do I need an HSV test?
The Centers for Disease Control and Prevention (CDC) does not recommend HSV testing for people without symptoms of HSV. But you may need an HSV test if:
- You have symptoms of herpes, such as blisters or sores on the genitals or other part of the body
- Your sex partner has herpes
- You are pregnant and you or your partner has had a previous herpes infection or symptoms of genital herpes. If you test positive for HSV, your baby may need testing as well.
HSV-2 may increase your risk of HIV and other sexually transmitted diseases (STDs). You may need a test if you have certain risk factors for STDs. You may be at higher risk if you:
- Have multiple sex partners
- Are a man who has sex with men
- Have a partner with HIV and/or another STD
In rare cases, HSV can cause encephalitis or meningitis, life-threatening infections of the brain and spinal cord. You may need an HSV test if you have symptoms of a brain or spinal cord disorder. These include:
What happens during an HSV test?
HSV testing is usually done as a swab test, blood test, or lumbar puncture. The type of test you get will depend on your symptoms and health history.
- For a swab test, a health care provider will use a swab to collect fluid and cells from a herpes sore.
- For a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
- A lumbar puncture, also called a spinal tap, is only done if your provider thinks you may have an infection of the brain or spinal cord. During a spinal tap:
- You will lie on your side or sit on an exam table.
- A health care provider will clean your back and inject an anesthetic into your skin, so you won’t feel pain during the procedure. Your provider may put a numbing cream on your back before this injection.
- Once the area on your back is completely numb, your provider will insert a thin, hollow needle between two vertebrae in your lower spine. Vertebrae are the small backbones that make up your spine.
- Your provider will withdraw a small amount of cerebrospinal fluid for testing. This will take about five minutes.
- Your provider may ask you to lie on your back for an hour or two after the procedure. This may prevent you from getting a headache afterward.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for a swab test or a blood test. For a lumbar puncture, you may be asked to empty your bladder and bowels before the test.
Are there any risks to the test?
There is no known risk to having a swab test.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
If you had a lumbar puncture, you may have pain or tenderness in your back where the needle was inserted. You may also get a headache after the procedure.
What do the results mean?
Your HSV test results will be given as negative, also called normal, or positive, also called abnormal.
Negative/Normal. The herpes virus was not found. You may still have an HSV infection if your results were normal. It may mean the sample didn’t have enough of the virus to be detected. If you still have symptoms of herpes, you may need to get tested again.
Positive/Abnormal. HSV was found in your sample. It may mean you have an active infection (you currently have sores), or were infected in the past (you have no sores).
If you tested positive for HSV, talk to your health care provider. While there is no cure for herpes, it hardly ever causes serious health problems. Some people may only have one outbreak of sores their whole lives, while others break out more often. If you want to reduce the severity and number of your outbreaks, your provider may prescribe a medicine that can help.
Is there anything else I need to know about an HSV test?
The best way to prevent genital herpes or another STD is to not have sex. If you are sexually active, you can reduce your risk of infection by
- Being in a long-term relationship with one partner who has tested negative for STDs
- Using condoms correctly every time you have sex
If you’ve been diagnosed with genital herpes, condom use can reduce your risk of spreading the infection to others.