Herpes Testing

What type of test is used? 

Virus culture or molecular methods like Polymerase chain reaction (PCR). Polymerase chain reaction (PCR), also called Nucleic Acid Amplification Test (NAAT), detecting herpes simplex virus DNA are the most commonly used test.

How is it used?

The test is used in two ways:

• to detect the presence of herpes simplex virus, and
• to screen sexually active people

Your doctor may use the test if you have a blister or vesicle on your genitals or mouth. Any sore in the genital area can be a symptom of a serious disease and should be tested.

A positive test result (virus culture or detection of herpes simplex virus DNA) on a scraping from a vesicle indicates an active infection.

There are two types of herpes simplex virus (HSV): 

• HSV‑1 typically causes fever blisters or cold sores on the mouth or face, which is called oral herpes. 
• HSV‑2 typically causes vesicles in the genital area and is called genital herpes.

The type of infection depends on the location of the virus more than on the type of virus – each type can cause either genital or oral infections if that is where it is contracted.

Blood tests are not useful for the initial diagnosis of HSV infection but they are available to for determining which type of HSV a person has been infected with, although they are not completely reliable for differentiating between HSV1 and HSV2. Most doctors rely on visual inspection of any lesions and culture or molecular tests on the scrapings taken from the infected area. Virus’s is grown in culture can be typed using specific antisera for HSV 1 and HSV 2 and molecular methods can distinguish between the two types of HSV.

Active herpes simplex virus infections can make people more susceptible to HIV infection and can make people who have HIV more infectious to others.

HSVs are transmitted through direct contact, which can include kissing; vaginal, oral, or anal sex; or other skin-to-skin contact. Genital herpes is most easily contracted by having sex with someone who has a vesicle, but it can be transmitted even if there are no sores or other symptoms. People often catch it by having unprotected sex with someone who doesn’t know they are infected.

Many people who have herpes don’t know it because they never have symptoms or don’t recognise the symptoms they do have. When you are first infected, you may have obvious and painful lesions at the site of infection. These lesions appear within two weeks after the virus is transmitted and usually heal within two to four weeks. The vesicles can appear in the vaginal area, on the penis, around the anus, or on the buttocks or thighs. This primary episode can include a second outbreak of lesions and even flu-like symptoms of fever and swollen glands. However, you may not have any lesions or have symptoms that are so mild that you don’t notice them or mistake them for something else, such as insect bites or a rash.

After the primary episode, the virus goes into an inactive state within your body. It may cause outbreaks from time to time. The outbreaks, which last about a week, can be blisters or open sores that crust over and then disappear. Sometimes, the virus can become active and infectious with no noticeable sores. The virus never goes away, and the frequency and severity of these recurrent episodes vary greatly among individuals.

There is no cure for herpes. Some drugs can reduce the frequency and shorten the length of outbreaks. The most effective drug currently available is aciclovir. It stops the virus from reproducing by interfering with its DNA.

Seventy percent of UK adults have oral herpes. About 10 percent of adults have genital herpes, but up to two-thirds of them don’t know because their symptoms are so mild.

See the Herpes Viruses Association website from the Related Pages section.