Anti-IgM Antibody to *Giardia lamblia* (Serum)

What This Test Measures

The test detects IgM antibodies, a type of immune protein your body makes shortly after infection. IgM levels rise quickly but typically decline within months as your immune system produces other protective antibodies. This test is most useful for diagnosing recent or acute infection.

Why It’s Ordered

Your healthcare provider may recommend this test if you’ve traveled to areas with poor sanitation, experienced unexplained diarrhea, abdominal pain, or bloating, or if you’ve had recent contact with someone known to have *Giardia*. It’s also used to confirm suspected cases in people with persistent symptoms.

How It’s Performed

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where it’s analyzed using an immunoassay method to detect IgM antibodies against *Giardia*. Results are reported as either positive or negative, with no numeric reference range provided for general interpretation.

What the Results Mean

A positive result indicates recent exposure to *Giardia* and suggests active infection. A negative result means either you haven’t been exposed recently or your infection has resolved. False positives are rare but possible, especially if you’ve had prior exposure.