HSV is a contagious condition that causessores around the mouthor genitals.
The IgM test does not detect herpes directly.
Instead, it looks for IgM, a key in ofantibody.
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This is a protein produced by the immune system in response to a herpes infection.
This article explains the purpose of the herpes IgM test.
It also discusses what the results mean, as well as retesting considerations.
What Is the Purpose of a Herpes IgM Test?
The herpes IgM test is a simple blood test and results are usually available within a week.
You may want to wait even longer depending on which tests are available in your area.
The test might also deliver a positive result during a recurrent oral or genital herpes episode.
How Are the Results Interpreted?
Results of a herpes IgM test are usually reported as positive, negative, or equivocal.
Herpes IgM test results:
Is It a New or Recurrent Infection?
Herpes IgM levels tend to go up early in an infection, and levels often go down with time.
This means a positive herpes IgM result is most often associated with a new infection.
However, individuals with recurrent herpes infections may also have positive herpes IgM blood results.
A positive IgM test alone is more likely to be a new infection.
Is It Possible to Get a False Positive Result?
Afalse positiveis when a test says you have a condition that you actually don’t have.
This can happen with the herpes IgM blood test.
In some cases you may not be infected at all.
However, you may have a different virus that triggers a positive on this blood test.
Should I Get Tested Again?
Summary
A herpes IgM test can detect early HSV infection by looking for IgM antibodies.
Your body produces IgM and IgG antibodies after HSV infection.
The IgM test can detect HSV earlier than the IgG test.
A positive IgM test might mean you have a new or recurrent HSV infection.
If you have a positive IgM test and a negative IgG test, you likely have a new infection.
To verify your test result, consider following up with your healthcare provider in six months for repeat testing.
Frequently Asked Questions
HSV IgG and HSV IgM are antibodies produced to fight the herpes simplex virus.
Blood tests can look for these antibodies to diagnose herpes.
A positive HSV IgM blood test indicates that herpes immunoglobulin M is present.
This means the person is carrying the herpes virus.
A false positive is possible.
A positive HSV IgG blood test indicates that herpes immunoglobulin G is present.
This means the person is carrying the herpes virus.
An HSV IgG test will not be positive in the early stages of an infection.
Centers for Disease Control and Prevention.Genital herpes.
2014;8(12):DC16-9.
1993;31(12):3157-64.
2006;12(5):463-9.
