Antibody to *Giardia lamblia* (IgG) – Serum
This test checks for antibodies in your blood that your immune system makes in response to *Giardia lamblia*, a microscopic parasite that can cause intestinal infections.
["Helps diagnose long-term infection from the parasite *Giardia* that may not cause immediate symptoms."]
Key facts at a glance
- LOINC
- 80683-6
- Short code
- G lamblia 18S rRNA Stl Ql NAA+probe
- Synonyms
- G lamblia 18S rRNA Stl Ql NAA+probe
- Category
- chemistry
- Sample
- stool
- Container
- Clean container
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 g
- Stability
- Refrigerated: 24h, Frozen: 7d
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
The test detects IgG antibodies, which are part of your immune system’s long-term defense. These antibodies appear after your body has been exposed to *Giardia lamblia* and can linger for months or years, even after the infection has cleared. This test is not used to diagnose an active infection but rather to identify past exposure.
When You Might Need This Test
Your healthcare provider may order this test if you’ve traveled to areas with higher risk for *Giardia* infection, have unexplained digestive symptoms (like chronic diarrhea, bloating, or stomach cramps) that persist despite other tests, or if you’ve been exposed to someone with a *Giardia* infection.
What to Expect Before the Test
No special preparation is needed. You’ll have a simple blood draw, usually taken from a vein in your arm. The process takes a few minutes, and you may feel a slight pinch or discomfort, but it’s generally not painful.
What the Results Mean
A positive result means your body has produced antibodies against *Giardia lamblia*, suggesting past exposure. A negative result means no detectable antibodies were found, but it doesn’t rule out an active infection—other tests (like stool samples) may be needed for that.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily useful for identifying past infections in people with persistent symptoms or those at higher risk (e.g., travelers, immunocompromised individuals). It doesn’t indicate whether you currently have an active infection, which would require additional diagnostic testing such as stool exams or molecular tests. Antibodies can remain in your system for months or years, so a positive result doesn’t mean you’re contagious today.
Short name
IgG Anti-Giardia Antibody
Frequently asked questions
How long does it take to get results?
Can I have this test if I’m currently sick with diarrhea?
Does this test show if I have an active infection right now?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy