Toxicity screening for Giardia duodenalis (Giardia intestinalis) antibodies – Immunoassay

Why This Test Might Be Ordered

Your doctor may recommend this test if you’ve recently experienced symptoms like persistent diarrhea, stomach cramps, bloating, or unexplained weight loss—especially if you’ve traveled to areas with poor sanitation or had recent contact with someone who has a Giardia infection. It’s also used to monitor treatment effectiveness or diagnose recurrent symptoms.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test looks for antibodies (proteins your immune system produces) that indicate past or current exposure to Giardia.

What the Results Mean

A positive result means your body has detected Giardia antibodies, suggesting you’ve been infected at some point. A negative result indicates no detectable antibodies, meaning either you’ve never been exposed or your immune system cleared the infection. Results alone don’t confirm active infection—your doctor may order additional tests (like stool samples) to diagnose current illness.

Common Symptoms of Giardia Infection

Giardia often causes mild to severe gastrointestinal issues, including watery diarrhea (sometimes with foul-smelling stools), stomach pain, bloating, gas, nausea, and sometimes loss of appetite or weight. Symptoms can range from mild to severe and may last weeks or months. Some people may not have symptoms at all.