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Herpes Simplex Virus Type 2 Immunoglobulin M Antibody (IgM) in Serum/Plasma

Published: August 9, 2026Updated: August 16, 2026

This test detects antibodies to the herpes simplex virus type 2 (HSV-2), which can help identify recent infection with genital herpes caused by HSV-2.

Quick summary

["IgM antibodies may appear shortly after infection and can help track early exposure to HSV-2."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
31412-0
Short code
HSV2 IgM Fld-aCnc
Synonyms
HSV2 IgM Fld-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

The test measures the presence of Immunoglobulin M (IgM) antibodies specific to HSV-2. IgM is one type of antibody your immune system produces in response to infection. If these antibodies are detected, it suggests you may have been recently exposed to HSV-2.

Why It’s Done

Your healthcare provider may order this test if you have symptoms like sores, pain, or unusual discharge in the genital or anal area, or if you have a history of genital herpes. It can also be used to confirm a recent infection in individuals with no prior history of HSV-2.

How It Works

The test uses an immunoassay method to detect HSV-2 IgM antibodies in your serum or plasma. This involves mixing a small sample of your blood with antibodies specific to HSV-2. If HSV-2 antibodies are present, they will bind to the test, triggering a measurable reaction that confirms the presence of infection.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into your arm to draw blood. If you are pregnant, breastfeeding, or have certain medical conditions, let your healthcare provider know before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HSV-2 IgM Antibody

Frequently asked questions

What Does a Positive Result Mean?
A positive result indicates recent infection with HSV-2, meaning you likely encountered the virus within the past few weeks to months. This does not mean you are currently contagious at the time of testing, but it confirms exposure. If you have symptoms, this test can help confirm genital herpes caused by HSV-2.
What Does a Negative Result Mean?
A negative result means your body either did not encounter HSV-2 recently or your immune system has cleared the virus. However, HSV-2 can remain latent (inactive) in your body for years. If you have symptoms or a history of genital herpes, further testing may be needed to confirm the diagnosis.
How Often Should I Get This Test?
This test is typically done once to confirm recent infection. If you have ongoing symptoms or a history of herpes, your healthcare provider may recommend follow-up testing or other diagnostic methods, such as viral culture or PCR testing, to monitor your condition or confirm active infection.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy