Immune response to Parvo B19
The immune response in primary Parvo B19 infections is characterised by the production of IgM and IgG antibodies. IgM antibodies which speak for acute infections, in most individuals are present within 1-2 weeks after the initial exposure and may be detectable for 2-3 months. Anti-Parvo B19 IgG appears around the end of the third week and seems to persist at detectable antibody level lifelong providing the organism a long-term protection. The detection of IgG is generally not useful for diagnosis of acute infection, apart from detecting a seroconversion in immunocompromised patients, who may not be able to produce IgM.

Diagnosis
Serological diagnosis of Parvo B19 infections for the detection of IgM and IgG antibodies is performed with various enzyme-linked immunoassays (ELISA), immunofluorescence assays (IFA) or western blots (WB).

Indications for Parvo B19 serology in the field of transfusion medicine employing the medac Parvo B19 tests:
• Selection of Parvo B19 IgG-positive blood donors for particular risk groups

The following test systems are available:
Parvo-B19-IgM-ELA Test PKS medac (qualitative)
Parvo-B19-IgG-ELISA PKS medac (quantitative, WHO-standardised)

Both assays base on the recombinant particulate structure proteins VP1 and VP2 from the baculovirus expression system.

For test procedure and test performance please refer to the corresponding Directions for use.