Genital Herpes Screening FAQ

Genital herpes is a common sexually transmitted disease (STD). It is caused by herpes simplex virus type 1 (HSV-1) or herpes simplex virus type 2 (HSV-2). Most people who have HSV-1 or HSV-2 don’t have symptoms.

There are a lot of questions about herpes tests, and this page will help you understand CDC’s herpes testing recommendations.

Genital herpes is common. Why doesn’t CDC recommend testing everyone for this STD?

CDC does not recommend herpes testing for people without symptoms. This is because diagnosing genital herpes in someone without symptoms has not shown any change in their sexual behavior (e.g., wearing a condom or not having sex) nor has it stopped the virus from spreading. Also, false positive test results (test results that say you have herpes when you do not actually have the virus) are possible. Even if you do not have symptoms, you should talk openly and honestly about your sexual history with your doctor to find out if you should be tested for any STDs, including herpes.

Although CDC does not recommend that everyone get tested for herpes, herpes testing may be useful in some situations. Herpes blood tests (also called type-specific HSV serologic tests) might be useful

• If you have genital symptoms that could be related to herpes,
• If you have (or have had) a sex partner with genital herpes, or
• If you want a complete STD exam, especially if you have multiple sex partners.

Please note that while a herpes blood test can help determine if you have herpes infection, it will not be able to tell you who gave you the infection.

Why is testing for genital herpes only recommended for people who have symptoms?

CDC recommends herpes testing for people who have genital symptoms for herpes to confirm that they are infected. These events are called “having an outbreak,” and they appear as blisters on or around the genitals, rectum, or mouth. The blisters break and leave painful sores that may take weeks to heal. Testing allows a doctor to talk with you about what to expect in the future, which medications are available to help manage any symptoms, and how you can lower your risk of spreading the infection to your sex partner(s).

If you have a partner with genital herpes, testing can tell if you also have the virus. If you are not infected, your doctor can talk to you about ways to lower your risk of getting genital herpes. If you are a pregnant woman and have a partner with genital herpes, it is very important to get tested.  If you get genital herpes during pregnancy your baby could also become infected. Herpes infections in babies can be life-threatening. If you are infected, your doctor will talk to you about your diagnosis and the possible symptoms of genital herpes. In addition, herpes blood testing may be useful if you are seeking a complete STD exam, especially if you have multiple sex partners.

Is a blood test for genital herpes included when I ask to be tested for "everything" (all STDs)? Why does CDC recommend testing for other STDs, but not herpes?

Herpes blood tests may or may not be included. Your doctor chooses STD tests based on your sexual behaviors (number of sex partners, if condoms are used every time, etc.), as well as how common the infection is in the area that you live in. This is why you should have an open and honest discussion with your doctor about your sex practices and history. When you go in for STD testing, it is important to ask your doctor which infections you are and are not being tested for, and why.

STD tests are usually done for infections that have serious outcomes if they are not treated. For example, finding and treating curable STDs like chlamydia can stop them from causing serious complications like infertility (the inability to get pregnant) in women. Genital herpes does not usually result in serious outcomes in healthy, non-pregnant adults. More often, the stigma and shame from a genital herpes infection can be more troubling to someone who is infected than the disease itself. If you are worried about genital herpes, you should talk with your doctor about whether you should be tested.

Wouldn’t testing everyone stop the spread of genital herpes?

We don’t know. There is no evidence that diagnosing genital herpes with a blood test in someone without symptoms would change their sexual behavior and stop the virus from spreading. In addition, without knowing the benefits of testing, the risk of shaming and stigmatizing people outweighs the potential benefits. For these reasons, testing everyone for herpes is not recommended at this time.

If a pregnant woman gets genital herpes is there a chance her baby can get infected?

Yes. Even though adults with genital herpes may not have any symptoms, herpes infections in babies can be life-threatening. Women who get genital herpes during late pregnancy have a very high risk for having a baby with herpes infection, and these women may not even know they are infected. Women who get herpes during early pregnancy, or who are infected before they get pregnant can also spread herpes to their babies. Most babies with herpes get infected as they come into contact with the herpes virus while passing through the birth canal, but infection can also occur before birth (congenital infection) or in the weeks after birth.

If you are pregnant and think that you or your partner may have genital herpes, tell your doctor. Your doctor can order testing and can talk to you about ways to lower your baby’s risk for infection.

Are people with genital herpes at increased risk of getting infected with HIV?

Yes, studies show that HSV-2 infection increases the risk of getting HIV infection, even when there are no symptoms of genital herpes. HSV-2 infection can cause tiny breaks in the genital and anal area that allow HIV to enter into the body. Herpes infection also attracts the type of cells that HIV infects (“target cells”) to the genital area. This increases the chance of getting HIV, if exposed.

Can testing and treating genital herpes decrease the risk for HIV infection?

No. Studies show that testing for genital herpes and treating with herpes medications does not lower the risk of getting HIV.

Why are there state-by-state data for common STDs, but not for genital herpes?

Syphilis, gonorrhea, and chlamydia are “notifiable” diseases in the United States, but herpes is not. A disease is “notifiable” if healthcare providers in all 50 states are required by law to report the diagnosis to their state or local health departments. CDC is also notified, and publishes state-by-state data for these infections. Because herpes infections are not notifiable infections by law, CDC is not able to provide state-by-state data. Public health surveillance for herpes infections is mainly done through population-based, national surveys, such as the National Health and Nutrition Examination Survey (NHANES).

Who decides which diseases are notifiable and why?

The Council of State and Territorial Epidemiologists (CSTE) works with CDC to determine if a particular disease should be nationally notifiable. To make this decision, they follow a number of public health principles, for example, (1) whether or not it is treatable; (2) whether or not it is preventable; (3) how common it is; (4) whether or not a public health response is needed; (5) whether or not there is a good source of information on the number of cases; and (6) whether or not it represents a significant public health threat (For example, how severe it is). Information on HSV-1 and HSV-2 infections already exists in NHANES, so herpes infections have not been classified as notifiable diseases.

Why have false positive tests been used as an argument against routine testing for genital herpes, but not for other STDs, which can also have false positives?

False positive test results are test results that say a person has a disease or condition when they do not actually have it. False positive results can occur with many diagnostic tests, including STD tests. The chances of false positive results increase as the likelihood of the infection decreases in the person being tested. False positive HSV-2 results can happen, especially in people who are at low risk for a herpes infection. Also, we do not know if people who test positive for herpes will change their sexual behavior as a result of a positive test. This tells us that the harm of a possible false positive test may be a greater concern than the benefits of an actual diagnosis. Unlike curable STDs, such as chlamydia, herpes infections are life-long, so it is especially important to avoid a false positive test.

Is Alzheimer’s disease related to HSV-1 infection?

Alzheimer's disease is a progressive brain disease that develops as a result of a complex series of events occurring in the brain over a long period of time. The causes of Alzheimer’s disease may include genetic, environmental, and other factors. Several different factors have been statistically linked to Alzheimer’s disease, including HSV-1 infection. However, some investigations suggest that viruses other than HSV-1 may influence Alzheimer's disease. More research is needed to determine whether or not there is a causal link between HSV-1 infection and Alzheimer’s disease.

I tested positive for genital herpes. Where can I find the latest information about ongoing genital herpes research, including clinical trials?

The U.S. National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID) supports research to develop prevention methods and treatments for genital herpes. Details about current research efforts can be found on the NIAID website. NIH also maintains a database with information about clinical trials around the world. This database includes information on all genital herpes studies that are actively recruiting volunteers.