Toxicity Screening for Giardia lamblia (Serum/Plasma) – Immunoassay

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like stomach cramps, diarrhea, bloating, or nausea—especially if you’ve traveled to areas with poor water sanitation or recently consumed potentially contaminated food/water. It’s also used to confirm a diagnosis when other tests (like stool samples) are inconclusive or if symptoms persist despite treatment.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample from a vein in your arm. The test checks for antibodies (proteins) your body makes to fight Giardia, not the parasite itself.

What the Results Mean

Positive results indicate your immune system has detected Giardia exposure, suggesting past infection or ongoing immune response. Negative results mean no detectable antibodies, but Giardia could still be present without an immune reaction (e.g., early infection). Follow-up testing (like stool exams) may be needed.

Common Causes of False Results

False positives may occur if you’ve recently been treated for another infection or have a weak immune system. False negatives can happen if infection is very early or severe, or if the test was done too soon after exposure.