IgG Antibody to *Babesia microti* (Serum)

Why This Test Matters

This test is used primarily to identify whether you’ve had an infection with *Babesia microti* in the past. It’s not typically used for diagnosing an active infection, as acute cases are usually managed with blood tests for parasites or symptoms. However, it can be useful in certain cases, such as evaluating long-term effects or confirming exposure in people with persistent symptoms.

What to Expect Before the Test

No special preparation is needed for this test. You’ll have a blood sample drawn from a vein, usually in your arm. The process is quick and typically causes only mild discomfort. If you’re taking blood thinners or have a history of bleeding disorders, let your provider know before the test.

What the Results Mean

A positive result indicates you’ve likely had an infection with *Babesia microti* at some point. However, antibodies can remain in your system for years after the infection has cleared. A negative result means you probably haven’t been exposed recently, but it doesn’t rule out past exposure entirely. Your healthcare provider will discuss the results in the context of your symptoms and medical history.

When This Test Might Be Ordered

Your doctor may recommend this test if you’ve had symptoms of babesiosis (such as fever, chills, fatigue, or anemia) and live in or have traveled to areas where *Babesia microti* is common. It may also be used in people with persistent symptoms after a tick bite or those with a history of tick-borne illnesses.