Home Biomarkers Herpes Semplex Virus II IgM

Herpes Semplex Virus II IgM

STDs Biomarker

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Collection Type: Blood

Body System

Related System: STDs

Overview

Herpes Simplex Virus type 2 (HSV-2) IgM is a blood test that detects IgM-class antibodies directed against HSV-2. IgM antibodies typically arise early after infection and are used as a marker of recent or acute infection, most often genital herpes. The test helps evaluate patients with new painful genital or perianal vesicles, ulcers, dysuria, fever, or tender inguinal lymphadenopathy. Results can vary by age, immune status and timing: younger sexually active adults have higher incidence, pregnant women and immunocompromised patients have special clinical importance, and early testing can be falsely negative during the window period. Cross‑reactivity with HSV‑1 and non‑specific IgM responses can produce false positives.

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Test Preparation

No special preparation is required

Why Do I Need This Test

Profile: STDs - Symptoms: new genital/perianal blisters, ulcers, dysuria, fever, adenopathy - Diagnoses/monitoring: acute/recent HSV-2 infection, assessment in pregnancy or exposure - Reasons for abnormal levels: recent primary infection, possible reactivation, cross-reactivity or false-positive assay - Biological meaning: elevated IgM suggests recent immune response to HSV-2 - Behaviors/lifestyle: new sexual partners, unprotected sex, partner with known HSV - Family history: prior neonatal herpes or partner history of genital herpes increases testing need

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Understanding Test Results

Index <0.9 (negative): No serologic evidence of recent HSV-2 infection.
May represent no prior exposure or testing during the early window period before antibodies develop (false negative).
If clinical suspicion is high, repeat in 2–4 weeks or perform lesion PCR.
Index 0.9–1.1 (equivocal): Indeterminate result repeat testing in 2–4 weeks or use confirmatory testing (type‑specific IgG or PCR) to clarify.
Index >1.1 (positive): Suggests recent or acute HSV-2 infection.
A positive IgM can indicate primary infection but can also occur with reactivation, cross‑reactivity with HSV‑1, or false positives; interpret alongside clinical findings.
In pregnancy, a positive IgM raises concern for recent infection and may prompt urgent further testing (type‑specific IgG, repeat serology, and lesion PCR) and specialist obstetric counseling.
Immunocompromised patients may show atypical antibody patterns (delayed, absent, or persistent IgM).

Normal Range

Index (S/CO or COI): <0.9 (negative)

FAQs

Q: What does HSV-2 IgM positive mean?

A: HSV-2 IgM positive suggests recent or current infection with herpes simplex virus type 2, indicating the body has produced early-stage antibodies. IgM results can be unreliable—false positives or cross-reaction with HSV-1 occur—and may not distinguish new vs. reactivated infection. Confirm with symptoms, viral PCR/culture and HSV-2 IgG testing, and discuss diagnosis and treatment with a healthcare provider.

Q: Is HSV-2 IgM curable?

A: HSV‑2 infection is not curable. Detectable IgM antibodies can suggest recent or primary infection but are not definitive and can be unreliable; IgG testing is more specific. Presence of IgM doesn’t change that the virus persists lifelong. Antiviral drugs (acyclovir, valacyclovir, famciclovir) suppress outbreaks, reduce symptoms and lower transmission risk; suppressive therapy decreases recurrences and viral shedding.

Q: What happens if IgM is positive?

A: A positive IgM suggests a recent or current infection, since IgM is the first antibody type produced. It often prompts confirmatory tests (IgG, PCR) and clinical assessment. False positives or cross‑reactions can occur, so timing and symptoms matter. Your healthcare provider will interpret the result, advise on treatment, isolation if needed, and arrange follow‑up testing.

Q: Should I worry about HSV-2 positive?

A: You don't need to panic. HSV-2 is common and usually manageable: many people have mild or no symptoms. Antiviral medicines can shorten outbreaks and reduce transmission; daily suppressive therapy and condoms lower risk to partners. Tell sexual partners, get medical follow-up—especially in pregnancy or if immunocompromised—and seek testing/treatment for recurrent symptoms. Serious complications are uncommon with proper care.

Q: What does IgM mean?

A: IgM stands for immunoglobulin M, the first antibody class produced by B cells during an immune response. Typically a pentamer in blood, it efficiently agglutinates pathogens and activates complement, helping early infection control. Elevated IgM suggests recent or current infection, while levels fall as longer-lived IgG appears. IgM is used in diagnostic serology to identify acute or recent exposure.

Q: Can HSV be cured?

A: HSV cannot be cured. The virus stays latent in nerve cells and can reactivate. Antiviral medicines (acyclovir, valacyclovir, famciclovir) control outbreaks, shorten episodes, and reduce transmission risk; daily suppressive therapy lowers recurrence frequency. Good hygiene, avoiding sexual contact during outbreaks, and condoms reduce spread. Research continues on cures and vaccines.