Herpes Simplex Virus 1 (HSV-1) IgG

The Herpes Simplex Virus 1 (HSV-1) IgG test detects IgG antibodies in the blood, which indicate a past infection with HSV-1. HSV-1 is a common virus that typically causes oral herpes (cold sores), though it can also cause genital herpes in some cases. This test helps determine whether someone has been previously exposed to HSV-1.

1. What Is HSV-1 IgG?

• HSV-1 is a virus that usually causes cold sores around the mouth or lips.

• The immune system produces IgG antibodies after infection, usually becoming detectable 2–6 weeks after exposure.

• The presence of IgG antibodies means the person has had the virus at some point, even if symptoms were never present.

2. Why Is the Test Performed?

This test is used to:

• Determine if a person has been infected with HSV-1 in the past.

• Help diagnose herpes infections when symptoms are unclear.

• Screen individuals prior to organ transplant or during prenatal care.

• Identify asymptomatic carriers who may transmit the virus to others.

3. Interpreting HSV-1 IgG Test Results

🔹 Positive (Reactive):

• Indicates past infection with HSV-1.

• The virus remains in the body in a dormant state and can reactivate (e.g., cold sores).

• Does not indicate a recent or active outbreak.

🔹 Negative (Non-reactive):

• No IgG antibodies detected — likely no previous exposure to HSV-1.

• If recent infection is suspected, retesting after a few weeks may be recommended.

4. What Can Affect Test Accuracy?

• Testing too soon after exposure (before antibodies have developed).

• Immunosuppressive conditions that impair antibody production.

• Cross-reactivity with HSV-2 antibodies may occur in some tests (type-specific tests reduce this risk).

5. How Is the Test Performed?

• A blood sample is drawn from a vein.

• No fasting or special preparation is usually required.

6. When to See a Doctor

🚨 Contact your healthcare provider if you:

• Have symptoms of herpes (cold sores, blisters, tingling or burning).

• Are pregnant and need to know your herpes status for delivery planning.

• Are at risk of transmitting HSV to a partner or newborn.

🔹 Key Takeaways

✅ A positive HSV-1 IgG result indicates past exposure to herpes simplex virus type 1.

✅ The virus is lifelong and may reactivate, even if symptoms are rare or absent.

✅ The test helps assess infection status for medical, personal, or preventive care purposes.