Antibody to Flavivirus Nucleoprotein (IgG) – Serum

Why This Test Is Done

Doctors may order this test if you have symptoms like fever, headache, or body aches that could suggest flavivirus infection, especially if you’ve traveled to or lived in areas where these viruses are common. It may also be used to confirm a diagnosis after a suspected exposure or to evaluate immune response in vaccine recipients.

What to Expect Before the Test

No special preparation is needed. A blood sample will be drawn from a vein in your arm by a healthcare professional. You may feel a slight pinch, but it usually doesn’t cause discomfort. If you’re on blood-thinning medication, let your doctor know before the test.

What the Test Results Mean

Positive results indicate the presence of IgG antibodies, suggesting past infection or immunity. Negative results mean no detectable antibodies, which could mean you haven’t been exposed or your immune system hasn’t responded yet. Results alone don’t confirm active infection; they may be used alongside other tests or clinical findings.

Possible Side Effects or Risks

Most people experience only minor side effects, such as a small bruise, slight swelling, or mild pain at the injection site. Rarely, there may be a reaction to the blood draw, like dizziness or fainting. If you experience severe pain, excessive bleeding, or signs of infection (like redness or fever), contact your healthcare provider.