Herpes Testing
An IgG blood test is used to diagnose herpes simplex virus (HSV) infection.
This test does not detect the virus. Rather, it detects the IgG antibodies, or immune proteins, that your body produces in response to the viral infection.
Parts of the IgG protein, like all antibodies, are made by the immune system to attack specific disease-causing organisms (pathogens), like viruses and bacteria. HSV IgG is the type of antibody that is produced when a herpes infection occurs.
An HSV IgG test is typically used to confirm a genital herpes infection. It is not recommended as a general screening test for everyone. But it is recommended for pregnant women who are at risk of having genital herpes. Treatment can reduce the risk of transmission to the baby.
Notes:
- The Centers for Disease Control and Prevention (CDC) currently advises against HSV testing for people without symptoms. Doing so has not been shown to change sexual behaviors. It also doesn't reduce the rate of herpes transmission.
- It can take three to six weeks from the initial infection before enough IgG is produced to be detected.
IgG vs. IgM:
The IgG test is not the only antibody test used to detect HSV. There's also an HSV immunoglobulin M (IgM) test, which detects IgM.
Unlike IgG antibodies that stay in the body and can be detected for a lifetime, IgM antibodies don't last very long. They usually can only be detected during an active or recent infection.
Another advantage of the IgG test is that it's more accurate when it comes to telling the difference between HSV-1 and HSV-2:
- HSV-1 is the type of herpes primarily associated with cold sores.
- HSV-2 is the type that mainly causes genital herpes.
If you have clinical signs of an infection and your HSV IgG test is negative, repeat the test in about four to six weeks to confirm the results.
An HSV test with a positive (abnormal) IgG result means that you either have or have had an HSV infection at some point. Since a positive result means that your body has built an IgG immune response to HSV, a negative IgG test means that your body has never needed to do so and you have never been infected with HSV.
The results of your HSV blood test will generally be reported as either:
Positive: IgG detected
Negative: IgG not detected
Equivocal: Results unclear
If your test is equivocal, your healthcare provider might consider results of other tests you've had done to make your diagnosis. They might also recommend that you repeat the IgG test after a few weeks.
IgG results may be considered along with IgM results. IgG antibodies take longer to produce but last a lifetime. IgM antibodies are detectable after a few days, but they disappear within a few weeks.
- If you test positive for IgG and IgM, or just IgM, it's likely that you have a new infection.
- If you test positive for IgG but not IgM, you likely have an existing infection that has been around for at least two months.
That said, between 30% and 70% of people with recurrent infections test positive for IgM.
A false-negative result, in which your test result is incorrectly reported as negative for HSV antibodies, can sometimes occur. This happens, for instance, if you have your test within the window period, not allowing enough time to pass after a possible exposure. You may also have a false-positive result, in which the test result incorrectly reads as positive.
Herpesvirus 6 IGG (HHV-6)
Optimal range: 0 - 10 index
Human herpesvirus 6 (HHV-6) is a set of two closely related herpesviruses, HHV6-A and HHV6-B. Human Herpesvirus 6 (HHV-6) has long been suspected as one trigger for Chronic Fatigue Syndrome.
LEARN MOREHerpesvirus 6 IGM (HHV-6)
Optimal range: 0 - 20 indexHSV 1 IgG, Type Spec
Optimal range: 0 - 0.9 index
Herpes is a common viral infection caused by the herpes simplex virus (HSV). The virus exists as two main types, HSV-1 and HSV-2.
HSV testing identifies the presence of the virus in a sample from a blister, sore or fluid to diagnose an active herpes infection or testing detects antibodies in the blood to determine previous exposure to herpes.
Both HSV-1 and HSV-2 are contagious and periodically cause small fever blisters (vesicles) that break to form open lesions.
HSV-1 primarily causes blisters or "cold sores" around the mouth (non-genital sites).
HSV-2 usually causes lesions around the genital area.
However, both HSV-1 and HSV-2 can affect either the oral or genital areas.
LEARN MOREHSV 1 IgM Antibodies
Optimal range: 0 - 0.1 titer
A herpes IgM (immunoglobulin M) test is a blood test that can detect early herpes simplex virus (HSV) infection. Herpes IgM is one of the first types of antibody that appears after infection, so this blood test is the earliest one that can be used to detect herpes.
HSV is a contagious condition that causes sores around the mouth or genitals.
The IgM test does not detect herpes directly. Instead, it looks for IgM, a type of antibody. This is a protein produced by the immune system in response to a herpes infection.
The herpes IgM antibodies can take up to 10 days to develop after a primary infection with the virus.
LEARN MOREHSV 2 IgG, Type Spec
Optimal range: 0 - 0.91 index
Herpes is a common viral infection caused by the herpes simplex virus (HSV). The virus exists as two main types, HSV-1 and HSV-2.
HSV testing identifies the presence of the virus in a sample from a blister, sore or fluid to diagnose an active herpes infection or testing detects antibodies in the blood to determine previous exposure to herpes.
Both HSV-1 and HSV-2 are contagious and periodically cause small fever blisters (vesicles) that break to form open lesions.
HSV-1 primarily causes blisters or "cold sores" around the mouth (non-genital sites).
HSV-2 usually causes lesions around the genital area.
However, both HSV-1 and HSV-2 can affect either the oral or genital areas.
LEARN MOREHSV 2 IgM Antibodies
Optimal range: 0 - 0.1 titer
Herpes Simplex Virus is a common pathogen of humans. The clinical course of HSV in humans is extremely variable. Primary infection with HSV, either type 1 or 2, is unapparent or subclinical in a majority of cases.
When clinically apparent, HSV infections can range from minimal stomatitis to a fatal generalized infection. Some of the major clinical manifestations of HSV infections are acute gingivostomatitis, recurrent herpes labialis, keratoconjunctivitis, eczema herpeticum, encephalitis, and meningitis.
Generalized infections are normally confined to individuals with immune deficiency, immunosuppressed patients, or newborns.
There are two distinct types of HSV: Types 1 and 2.
HSV-1 and HSV-2 are closely related but they can be separated both serologically and biologically.
HSV-1 is associated with lesions above the waist (encephalitis, stomatitis, eye infections, and, in some cases, of generalized infections).
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