9348. Parvovirus B19, IgM antibodies

The IgM test for parvovirus B19 can detect acute or recent infection. It is important in cases of rash, anemia, or joint damage, as well as in pregnant women to assess the risk of intrauterine infection of the fetus.

Parvovirus B19 is the causative agent of an infection that often manifests as 'fifth disease' (erythema infectiosum) in children, but can have serious consequences in adults, pregnant women, and immunosuppressed patients.

After infection, IgM antibodies appear first, usually 7-10 days after the onset of illness. They are a marker of acute or recent infection and circulate in the blood for several weeks (sometimes up to 2-3 months).

Importance of detecting IgM to parvovirus B19:

• In pregnant women: acute infection in the first and second trimesters can cause non-immune hydrops fetalis, anemia, and intrauterine death.
• IgM indicates risk and requires PCR testing or prenatal monitoring.
• In children and adults: IgM confirms the acute phase of infection, which can manifest as a rash, low-grade fever, arthralgia, or cold-like symptoms.
• In patients with chronic anemia or immunodeficiency, it can cause aplastic crises, thrombocytopenia, and agranulocytosis.

A positive IgM result requires clinical interpretation, taking into account IgG results, the clinical picture, and, if necessary, confirmation by PCR. This is especially important during pregnancy, where diagnostic accuracy is crucial.

• Children and adults with symptoms of acute infection: fever, rash, joint pain, anemia.
• Pregnant women who have had contact with infected individuals or have symptoms of a viral infection – to assess the risk of fetal infection.
• Newborns with intrauterine growth retardation, hydrops, and anemia of unknown origin.
• Patients with sudden severe anemia, especially in hemolytic conditions (thalassemia, sickle cell anemia).
• Immunosuppressed patients – if viral persistence or reactivation is suspected.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: