Herpes Testing
Understanding the HSV IgG Blood Test
The IgG blood test is commonly used to diagnose herpes simplex virus (HSV) infections. Rather than detecting the virus itself, this test identifies IgG antibodies, which are immune proteins your body produces in response to the HSV infection.
What Does an IgG Test Detect?
Antibodies, such as IgG, are created by the immune system to target specific pathogens like viruses or bacteria. HSV IgG antibodies are produced when a herpes infection occurs and remain in the body for life, serving as markers of both current and past infections.
- HSV-1: Typically associated with cold sores.
- HSV-2: Primarily causes genital herpes.
The HSV IgG test is most commonly used to confirm genital herpes but is not recommended as a routine screening test for the general population. It is, however, advised for pregnant women at risk of genital herpes, as treatment can reduce the risk of transmission to the baby.
Key Points About HSV IgG Testing
-
Timeframe for Antibody Detection
IgG antibodies take about 3–6 weeks after the initial infection to reach detectable levels. Testing too early may result in a false-negative result. -
Testing Guidelines
The Centers for Disease Control and Prevention (CDC) advises against HSV testing for asymptomatic individuals, as it does not alter sexual behavior or significantly reduce transmission rates. -
Accuracy in Differentiating HSV Types
The IgG test is preferred over other antibody tests because it accurately distinguishes between HSV-1 and HSV-2 infections.
IgG vs. IgM Antibody Tests
In addition to IgG testing, an IgM test is sometimes used to detect HSV. Here’s how they differ:
- IgG Antibodies:
- Develop more slowly but remain in the body for a lifetime.
- Useful for identifying past or long-term infections.
- IgM Antibodies:
- Appear early during active or recent infections.
- Disappear within a few weeks, making them less useful for diagnosing past infections.
Interpreting Combined IgG and IgM Results
- Positive IgG and IgM: Likely indicates a new infection.
- Positive IgG only: Indicates a long-standing infection present for at least two months.
- Positive IgM only: Suggests a recent infection.
Note: Between 30% and 70% of people with recurrent infections may also test positive for IgM.
HSV IgG Test Results
Your test results will generally fall into one of three categories:
- Positive: IgG antibodies are detected, indicating a current or past HSV infection.
- Negative: No IgG antibodies are detected, meaning you have likely never been infected with HSV.
- Equivocal: Results are unclear; a repeat test may be recommended after 4–6 weeks.
Accuracy and Limitations of the IgG Test
-
False-Negative Results:
If the test is conducted too soon after exposure, IgG antibodies may not have developed yet, leading to a false-negative result. -
False-Positive Results:
Occasionally, a test may incorrectly report the presence of antibodies, suggesting an infection when none exists.
If your results seem inconsistent with your symptoms or potential exposure, your healthcare provider may suggest additional testing or a repeat IgG test to confirm the diagnosis.
Next Steps After Testing
- If your IgG test is positive, your doctor will review your medical history and symptoms to confirm the diagnosis.
- For equivocal results or suspected recent exposure, a follow-up test may be needed.
Treatment options vary based on whether the infection is active or recurrent. Managing HSV includes antiviral medications to reduce symptom severity, frequency of outbreaks, and the risk of transmission.
By understanding the purpose and limitations of the HSV IgG test, you can work with your healthcare provider to ensure accurate diagnosis and effective management of herpes simplex virus infections.
Show more
Biomarkers included in this panel:
This assay utilizes recombinant type-specific antigens to differentiate HSV-1 from HSV-2 infections. A index positive result cannot distinguish between recent and past infection. If recent HSV infection is suspected but the results are negative or eq
Learn moreA herpes IgM (immunoglobulin M) test is a blood test that can detect early herpes simplex virus (HSV) infection. HSV is a contagious condition that causes sores around the mouth or genitals. The IgM test does not detect herpes directly. Instead, it l
Learn moreHuman 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 moreThe detection of IgM antibodies specific to HHV-6 is a common diagnostic tool used to assess whether an individual has recently been exposed to or is currently experiencing an active infection with this virus. IgM antibodies are produced by the immun
Learn moreHHV-6 IgG antibodies are specific immunoglobulins that play a pivotal role in the serological diagnosis and understanding of infections caused by the Human Herpesvirus 6 (HHV-6). HHV-6, a member of the Betaherpesvirinae subfamily, is known for its ub
Learn moreHerpes 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 activ
Learn moreA 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 us
Learn moreThe marker HSV-2 IgG Inhibition, IA, refers to a specific immunological assay designed to detect IgG antibodies against Herpes Simplex Virus type 2 (HSV-2) in human serum or plasma samples. This assay is based on the principle of antibody inhibition,
Learn moreWhat is the HSV-2 IgG Screening Index? The HSV-2 IgG Screening Index is a blood test used to detect Immunoglobulin G (IgG) antibodies specific to the Herpes Simplex Virus Type 2 (HSV-2). HSV-2 is a common viral infection that primarily causes genital
Learn moreHerpes 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 activ
Learn moreThe marker "HSV 2 IgG, Type Specific Ab" on a herpes testing panel refers specifically to a blood test that checks for the presence of antibodies against the Herpes Simplex Virus type 2 (HSV-2). This type of virus primarily causes genital h
Learn moreHerpes 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 inf
Learn moreHuman Herpesvirus 6 (HHV-6) is a common virus that primarily infects children, causing a mild illness known as roseola, characterized by high fever and a distinctive rash. The presence of IgM antibodies against HHV-6 in the blood is a significant mar
Learn more