Description
The Parvovirus B19 Blood Test detects antibodies in your blood to determine if you have a current or past infection with Parvovirus B19, the virus responsible for Fifth Disease, a common childhood rash illness.
What the Test Measures
- IgM antibodies: Appear soon after infection and indicate a recent or current infection.
- IgG antibodies: Develop a few weeks after infection and indicate past exposure and immunity.
Why It’s Done
- To confirm recent or past Parvovirus B19 infection.
- To assess immunity in pregnant women, since infection during pregnancy can pose risks to the fetus.
- To evaluate unexplained anemia or joint pain, which can sometimes be caused by the virus.
- To help diagnose Fifth Disease in children presenting with a slapped-cheek rash or mild flu-like symptoms.
Symptoms of Parvovirus B19 Infection
- Rash on the face, arms, or legs (especially in children)
- Fever
- Fatigue
- Joint pain or swelling (more common in adults)
- Mild cold-like symptoms
Test Details
- Specimen: Blood sample
- Fasting: Not required
- Results:
- Positive IgM indicates recent infection
- Positive IgG indicates past infection and immunity
- Negative results suggest no prior exposure
This test is useful for diagnosing current infection, confirming immunity, and protecting at-risk populations, especially pregnant women and individuals with weakened immune systems.

