Health Encyclopedia

HSV DNA (CSF)

Does this test have other names?

Herpes simplex 1 infection, herpes simplex 2 infection

What is this test?

This test looks for the herpes simplex virus (HSV) DNA in your cerebrospinal fluid (CSF). It diagnoses herpes simplex infection in the nervous system. The test is especially useful to find out if HSV is causing an infection of the brain (encephalitis) or an infection of the fluid around the spinal cord and brain (meningitis).

There are two types of HSV: HSV-1 and HSV-2. HSV-1 generally causes oral herpes. Oral herpes causes blisters called cold sores. HSV-2 causes genital herpes. This causes sores on the genitals. Both types of herpes can also affect other parts of your body. Other symptoms might include headaches, fever, and general discomfort such as body aches.

HSV is the most common type of genital ulcer illness. First-time infections are usually more severe than later outbreaks.

You can get HSV from having unprotected sex with an infected partner. If your immunity is weakened, you may be more likely to get HSV. Menstruation, extreme tiredness (fatigue), increased stress, and illness can trigger an HSV outbreak.

In rare cases, HSV causes more severe infections. These include encephalitis and meningitis.

HSV can be passed during pregnancy to the unborn baby. Infection in the baby may affect the skin, eyes, mouth, central nervous system, or many organs.

You may have a miscarriage if your unborn baby gets herpes early in your pregnancy. You should not give birth to a baby through your vagina if you have an active herpes infection. A cesarean section is advised in this case. 

Why do I need this test?

You may be given this test if your healthcare provider thinks that you have meningitis or encephalitis caused by HSV.

Symptoms of HSV infection of the nervous system include:

  • Fever

  • General discomfort, such as body aches

  • Headache

  • For females, small sores on the cervix, vagina, and inner thighs

  • For males, sores on the glans and shaft of the penis and anal area

  • Confusion or disorientation

  • Seizures

  • Neck stiffness

What other tests might I have along with this test?

Your healthcare provider will also ask about your health history and give you a physical exam. You may also need blood tests or X-rays.

What do my test results mean?

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

A negative test result may mean that you don't have the infection. But false-negative results may happen. If your healthcare provider thinks you may have HSV infection and your test result is negative, the test may be repeated within 1 week.

How is this test done?

This test is done with a sample of your cerebrospinal fluid. Your healthcare provider will take the sample through a lumbar puncture (LP) using a thin needle. The needle will be pushed into your lower back, and fluid will be removed.

Does this test pose any risks?

A lumbar puncture has these risks:

  • Headaches

  • Infection

  • Bleeding

  • Tumors

  • Numbness

What might affect my test results?

Your normal activities won't affect your test results.

How do I get ready for this test?

You don't need to prepare for this test. But be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use. 

Online Medical Reviewer: Chad Haldeman-Englert MD
Online Medical Reviewer: Rita Sather RN
Online Medical Reviewer: Tara Novick BSN MSN
Date Last Reviewed: 9/1/2022
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