Giardia duodenalis Antigen, Stool (Qualitative Immunoassay)
This test checks for the presence of Giardia duodenalis, a microscopic parasite that can cause intestinal infections, often leading to diarrhea, stomach cramps, or bloating. It’s used to diagnose giardiasis, a common parasitic infection spread through contaminated food, water, or person-to-person contact.
["A positive result may indicate a giardiasis infection that needs treatment."]
Key facts at a glance
- LOINC
- 10723-5
- Short code
- T gondii IgA Ser IA-aCnc
- Synonyms
- T gondii IgA Ser IA-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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
Why Is This Test Done?
Your healthcare provider may recommend this test if you have symptoms like persistent diarrhea, stomach pain, bloating, or gas that don’t improve with usual treatments. It’s also used in people who have traveled to areas with higher parasite risks or those with weakened immune systems.
How Is the Test Performed?
You’ll need to provide a fresh stool sample (about 1 tablespoon) in a provided container. The sample is tested for Giardia antigens using an immunoassay method, which detects specific proteins from the parasite without needing to see the parasite under a microscope.
What Are Possible Results?
A positive result means the test found Giardia antigens in your stool, suggesting an active infection. A negative result means no detectable antigens were found, but this doesn’t always rule out infection if the sample wasn’t collected correctly or the infection is very early or resolved.
What Does a Positive Result Mean?
A positive result strongly suggests giardiasis, which requires treatment with antiparasitic medications. Follow your doctor’s advice for next steps, including possible follow-up tests to confirm the infection is cleared.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Giardia duodenalis is a common intestinal parasite that can cause chronic diarrhea, nausea, or malabsorption. Symptoms may range from mild to severe and can last weeks or months. Early diagnosis is important to prevent dehydration or malnutrition, especially in children or people with weakened immune systems.
Short name
Giardia Stool Test (Qualitative)
Frequently asked questions
What are the common symptoms of giardiasis?
How is giardiasis typically treated?
Can giardiasis be spread to others?
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 16, 2026. · Read our editorial policy