Infectious DiseaseInfectious Disease

HSV 2 IgM

Normal Range
< 0.90 Index
Sample Type
Serum
Fasting
No
Unit
Index

Function

Herpes Simplex Virus Type 2 (HSV-2) is the primary cause of genital herpes. The IgM test is designed to detect early-stage antibodies produced by the immune system in response to a recent infection. IgM is typically the first antibody to appear after exposure to the virus, usually appearing within 1-2 weeks and potentially staying detectable for several months.

Why it is Ordered

This test is ordered when a patient presents with symptoms of a primary genital herpes infection, such as painful blisters, sores, or flu-like symptoms. It is used to distinguish between a new (acute) infection and a long-standing (chronic) infection. However, modern clinical guidelines often favor Type-Specific IgG testing or PCR swabs of active lesions due to the cross-reactivity and potential for false positives in IgM testing.

Associated Conditions

  • Primary Genital Herpes: The initial infection with the HSV-2 virus.
  • Neonatal Herpes: Screening in pregnant women to prevent transmission to the newborn during delivery.
  • Meningitis/Encephalitis: In rare cases, HSV-2 can cause neurological inflammation, requiring antibody testing in the blood or CSF.

Check Your Result

Check Your Result

Interactive
Index

Enter your lab result to see where you stand compared to the standard reference range.

Why Context Matters

HSV-2 IgM testing is notorious for 'false positives.' The test can cross-react with other viruses in the herpes family, such as HSV-1 (cold sores) or Varicella-Zoster (chickenpox). Additionally, IgM can reappear during a recurrence of an old infection, making it difficult to determine if the infection is truly 'new.' A second opinion usually involves an IgG type-specific test or a Western Blot, which is the gold standard for confirmation.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for HSV 2 IgM:

Related Indicators

DR

Medically Reviewed by Dr. Binoy Babu, MBBS

Board Certified Doctor • 10+ Years Clinical Experience

Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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