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Genital Herpes: Diagnosis and treatment


Herpes can be detected by a viral culture of a lesion, if one is present, or by a blood test. Some experts recommend both methods.

With a viral culture, a doctor swabs a lesion to pick up cells, puts the swab in a special solution, and sends it to a lab for growing and analyzing.

Although a doctor may recognize a herpes lesion by examining it, a viral culture will confirm the presence and type of HSV. Once they know whether they have HSV-1 or HSV-2, people have a better idea of how often they will have recurrences.

But viral cultures do have their drawbacks. If the lesion has started to heal (usually 48 hours after its appearance), the swab may not pick up enough virus and the culture result will be a "false negative." (False positives in cultures are rare.)

A blood (serology) test can be used to confirm a negative culture. It can also be used to diagnose herpes in a person who has no symptoms, who has genital irritation but isn't sure it's herpes, or who has a sexual partner with herpes and wants to find out if he or she has already become infected.

"Diagnosing whether someone has herpes or not is quickly done by a serology test because once you've become infected, an immune-competent individual will develop antibodies to the herpes that is infecting them," says Thomas Simms, a biologist in the FDA's Center for Devices and Radiological Health.

Herpes antibodies will usually show up in the blood several weeks after a person first becomes infected. Some blood tests can determine the type of herpes infection, but cannot indicate whether the herpes is oral or genital. So people without symptoms may not know for certain if their herpes is oral or genital.

In the past several years, the FDA has cleared three blood tests that accurately determine if a person is infected with HSV-1 or HSV-2. The HerpeSelect ELISA Kits and the HerpeSelect Immunoblot Kit made by Focus Technologies of Herndon, Va., detect both types. The POCkit Rapid Test made by Diagnology Inc. of Cary, N.C., detects HSV-2 only.

Another blood test is the Western Blot. Although not 100 percent accurate, the Western Blot is considered the "gold standard" of blood tests and is used to determine the accuracy of other herpes blood tests that are developed. The University of Washington is the premier institution for performing and interpreting the test. (See "For More Information" to find out how you can have your blood tested with a Western Blot.)

Many older FDA-cleared blood tests for herpes are still on the market, and many labs use these tests because they are widely available and inexpensive. Although they may be labeled type-specific (can determine whether the infection is HSV-1 or HSV-2), they are not reliable, says Simms.

This is where a herpes support group can help. These groups usually keep a list of doctors who are up to speed, knowledgeable, and know what the right tests are.


Although there is no cure for genital herpes, there are medications that significantly reduce the frequency and duration of outbreaks and have few side effects in most people.

In 1985, the FDA approved Zovirax (acyclovir), the first genital herpes drug, which is now available in a generic form. More recently, the FDA approved two other drugs to treat genital herpes: Famvir (famciclovir) and Valtrex (valacyclovir).

All three of these oral antiviral drugs can be taken either episodically (when a person has an outbreak or feels one coming on), or suppressively (daily, to help prevent the recurrence of outbreaks). Acyclovir and valacyclovir are also FDA-approved to treat an initial episode of genital herpes to help heal the lesions and to lessen the pain.

When taken episodically at the first sign of a tingling or itching sensation, an antiviral drug may prevent an outbreak altogether. Once an outbreak occurs, if the treatment is started soon enough, the drugs can lessen the severity and shorten the healing time. When taken suppressively, the drugs don't always prevent outbreaks, but help them to occur less frequently.

The antiviral drugs work by interfering with DNA synthesis to prevent the virus from reproducing. Famciclovir and valacyclovir, which are better absorbed by the body, can be taken less often than acyclovir.

For more information:

National Herpes Resource Center, a service of the American Social Health Association:

Teen Web site for STDs:

National Herpes Hotline:

Centers for Disease Control and Prevention National STD and AIDS Hotlines:
1-800-227-8922 or 1-800-342-2437
En Español: 1-800-344-7432
TTY: 1-800-243-7889

University of Washington Virology Lab:

If you wish to be tested with the most accurate blood test for detecting herpes, the Western Blot, have your health care provider call 206-598-6066 to request the HSV type-specific serology information packet.

Patient Assistance Programs to help low-income people buy herpes drugs:

Novartis (maker of Famvir):

GlaxoSmithKline (maker of Valtrex and Zovirax):

Source: FDA ConsumerNews magazine (adapted from the American Social Health Association).

Posted: April 2002