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Serum or plasma concentration of immunoglobulin G (IgG) antibodies against West Nile virus

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

This test measures antibodies your immune system produces in response to exposure to the West Nile virus. It helps determine if you’ve been infected in the past.

Quick summary

["IgG antibodies indicate past exposure to West Nile virus, not current infection."]

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

Key facts at a glance

LOINC
60030-4
Short code
WNV IgG Ser Ql IF
Synonyms
WNV IgG Ser Ql IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
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

IgG antibodies are a type of protein your body makes to fight infections. If you’ve been exposed to the West Nile virus, your immune system will produce these antibodies over time. This test detects their presence in your blood, serum, or plasma.

Why It’s Done

Doctors may order this test if you’ve had symptoms of West Nile virus infection (like fever, headache, or neurological issues) or if you’ve traveled to areas where the virus is common. It can also help confirm a past infection if symptoms were unclear.

How the Test Works

A small blood sample is taken from your arm. The lab analyzes it to identify IgG antibodies against the West Nile virus using an immunoassay method, which detects specific proteins in your blood.

What to Expect Before the Test

No special preparation is needed. You may have a slight bruise or soreness at the injection site, but this is normal. If you’re on blood-thinning medication, let your doctor know before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

West Nile Virus IgG Antibody

Frequently asked questions

Why is this test important?
This test helps doctors confirm whether you’ve had West Nile virus infection in the past, even if you don’t remember symptoms. Unlike IgM antibodies (which indicate recent infection), IgG antibodies stay in your system for longer, offering a broader view of past exposure.
Can this test tell me if I have an active infection?
No, this test only detects past exposure. For active infection, your doctor may also check for IgM antibodies or other symptoms.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time.
  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