Diagnosis

Methods of testing include diagnosis by:

• Viral Culture
• Serologic tests (Blood tests)
• Antigen Tests

Viral Culture

Viral culture looks for the presence of the virus in the lesion.

Viral culture is very specific:

• it does not frequently give a positive result when something else is the culprit



• it can also be very sensitive if the specimen is adequate



• it also provides a way to tell whether the infection is caused by HSV-1 or HSV-2

Lots of people need to be tested more than once. The viral culture often misses herpes even when it is present. Often a patient who has received a negative culture result will be asked to come back again when a new genital lesion appears so the culture can be tried a second or third time.

Serologic Test(Blood tests)

They detect "antibodies. " These are substances produced by the immune system to fight off infection.
Blood Tests detect herpes by looking for antibodies in the blood or serum. Blood tests can be performed even when no symptoms are present. If antibodies are found in the blood, herpes simplex is latent in the body. Blood tests do not require swabbing a lesion, so they can be done long after symptoms have faded.
The sensitivity and specificity of blood tests is better than culture or antigen tests, but there are two important factors to consider.
The first factor is timing. If this is the first exposure to herpes, a person may take several weeks to develop the antibodies that the test looks for.
The second is that some blood tests cannot tell the difference between the two types of herpes, HSV-1 and HSV-2. For this reason, anyone seeking an accurate diagnosis of genital herpes must be sure to get a "type-specific" serologic test, which can accurately distinguish HSV-2 from HSV-1 antibodies. Most commercially available kit assays currently cannot make this distinction despite their claims.

Antigen Detection Tests

This is where components of the virus are specifically identified.It is used less frequently.It dentify herpes by the presence of antigens, fragments of the virus that are known to stimulate the immune response.
A swab is taken similar to the method used for viral culture. In general, antigen detection assays are less sensitive than viral culture. Antigen-detection is usually done only in research laboratories or large reference laboratories.
Antigen tests can produce results more quickly than cultures and are sometimes less expensive. However, better samples are needed than for cultures and many do not determine whether the sample is infected with HSV-1 or HSV-2.