What is a herpes (HSV) test?

A herpes test looks for signs of the herpes simplex virus (HSV), a common viral infection. Many people with HSV don't have any symptoms, but those who do often have painful blisters or sores on the affected parts of the body. These sores and other symptoms only last for several weeks. After their first appearance, they will fade and then come back in the future. These outbreaks tend to be milder over time.

A herpes test can be done using fluid from one of these sores during an outbreak or by using a sample of your blood if you have no symptoms.

There are two main types of this virus.

• HSV-1 usually causes oral herpes, which can result in cold sores ("fever blisters") on or around your mouth. Most people get oral herpes by the time they're young adults, usually from non-sexual contact with saliva (spit) from a person who has an HSV-1 infection. That may happen if you share forks, cups, or towels. HSV-1 can also cause genital herpes if you receive oral sex from a partner with a cold sore.
• HSV-2 is the most common cause of genital herpes. Genital herpes is a sexually transmitted infection (STI). This means you get it through sexual contact with a person who has a herpes infection, even if they don't have symptoms. HSV-2 can also spread to the mouth, causing oral herpes. This may happen if you give oral sex to a person who has genital herpes from HSV-2.

There is no cure for HSV, but medicines can help manage outbreaks. HSV usually doesn't cause any major health problems. But if you're pregnant and have genital herpes, you can pass the virus to your fetus before birth or during childbirth. This can lead to a life-threatening HSV infection for your baby.

Other names: herpes culture, herpes simplex viral culture, HSV-1 antibodies, HSV-2 antibodies, HSV DNA

What is it used for?

Generally, HSV tests are used to find out whether or not you have a herpes infection. However, there are different ways your health care provider can test for HSV, depending on whether or not there are sores present.

If there are sores or blisters, your provider will collect fluid from the sore using a swab. They can then use the fluid from the sore to test for the virus in one of two ways.

• A viral culture takes cells from the sample and grows them in a lab. After the culture of cells has grown, a lab technician will be able to check it for HSV.
• A polymerase chain reaction (PCR) test looks for genetic material from the HSV virus in the sample. This test is faster and more accurate than a viral culture. In the rare event that you have an HSV infection in your spine or brain, your provider may use this type of test.

If there are no sores or blisters, your provider will look for HSV antibodies in a sample of your blood. Antibodies are proteins your immune system makes to fight germs such as viruses and bacteria. So, if you have HSV antibodies, that means an HSV infection might be present. This test may be used on those who are at high risk of getting HSV.

Why do I need an HSV test?

The most common reason for needing an HSV test is if you have symptoms of an infection. These include:

• Blisters or sores on the mouth, genitals, anus, buttocks, or other areas of skin. The sores develop a crust as they begin to heal.
• Fever and flu-like symptoms.
• Swollen glands.
• Pain or tingling in the affected area.
• Discharge from the urethra and/or vagina.
• Painful urination (pee).

If you don't have symptoms, you may also need an HSV test if your partner has genital herpes or symptoms that might be genital herpes.

In general, medical experts don't recommend HSV testing for people without symptoms of HSV.

If you are being tested for other STIs, your provider may choose to include an HSV test based on your risk of exposure. You may be at higher risk of getting an HSV infection if you have:

• Multiple sexual partners.
• Other STIs.
• HIV.
• Sex without condoms or dental dams.
• Sex in exchange for money and/or drugs.

You may also be at higher risk for HSV infection if you are a man who has sex with other men.

Using condoms or dental dams can reduce your risk of getting or passing HSV. However, they can't provide complete protection. You can still get an infection from contact with areas of skin that the condom or dental dam doesn't cover.

Rare cases of HSV in the brain and spinal cord can lead to encephalitis or meningitis. You may need an HSV test if you have one of these serious conditions.

Because an HSV infection can be passed to a baby during childbirth, your provider may order an HSV test for your baby.

What happens during an HSV test?

If you get a swab test, a health care professional will use a swab to collect fluid and cells from a herpes sore that has not begun to heal yet.

If you get 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.

At-home tests are available for HSV. These tests usually use a sample of blood that you collect at home and send to a lab. Talk with your provider to find out if at-home testing is right for you.

If your provider thinks you have an HSV infection in your spinal cord or brain, you may have a test of your cerebrospinal fluid (CSF) to look for signs of the virus. CSF is a fluid that flows in and around your brain and spinal cord. A thin needle is inserted into your spine to remove a small amount of CSF. This procedure is called a lumbar puncture or spinal tap.

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 (pee) and bowels (poop) before the test.

Are there any risks to the test?

After a swab test, you may have a little bit of bleeding or discomfort where your skin was swabbed. This usually doesn't last long.

A blood test has very little risk. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

If you have a lumbar puncture, you may feel some pain or tenderness in your back where the needle was inserted. You may also have some bleeding at the site or a headache.

What do the results mean?

The meaning of your test results depends on the type of HSV test you had. To understand your results, your provider will consider your health history and any symptoms you have.

In general:

• Negative/Normal test results mean that signs of the herpes virus were not found in your sample, and you are unlikely to have an HSV infection. It's important to know that you can have a negative result when you really do have a herpes infection if you had a blood test for HSV antibodies too soon after an infection began. That's because your body takes up to three months to make HSV antibodies.
• Positive/Abnormal test results mean that signs of HSV were found in your sample. If you had a blood test that showed you have HSV antibodies, the antibodies could be from an active infection now or a past infection.

If you have HSV, treatment can help reduce the number of outbreaks and control your symptoms. It's important to know that having an HSV infection may increase your risk of getting HIV and other STIs. So, talk with your provider about HIV testing along with testing for other STIs.

It's also important to take steps to avoid spreading HSV to others. Using condoms can help. Since outbreaks come and go, ask your provider how to know when your risk for spreading the herpes virus may be high.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about an HSV test?

The best way to prevent genital herpes or another STI is not to have sex. If you are sexually active, you can reduce your risk of infection by:

• Having sex with only one person who has sex only with you (mutual monogamy) after both of you are tested for STIs.
• Using condoms correctly every time you have sex.