Diagnosis Of Parvovirus B19 In Pregnancy Enhanced With Launch Of A Unique Highly Sensitive Molecular Assay
The molecular division of DiaSorin has launched the unique, highly sensitive Iam Parvo assay, a rapid quantitative molecular assay for use on the Liaison® Iam instrument. DiaSorin are the global leader in Parvovirus B19 serology testing, and the addition of this molecular assay expands its diagnostic portfolio for this potentially life-threatening virus.
Parvovirus B19 (B19V) is a common childhood infection. It causes particular concern where a pregnant woman has had contact with a B19V infected individual, or where maternal B19V infection is suspected. During pregnancy, from as early as 6 weeks gestation, B19V can transfer from mother to foetus across the placenta. Such infection may cause hydrops fetalis, miscarriage or poor outcomes (including severe neurological disease) in surviving babies.
Diagnosis of maternal infection relies on the detection of IgM and IgG antibodies. The presence of IgG antibodies to B19V indicates a previous infection, but it is estimated that approximately 25 to 45% of women of childbearing age do not possess these antibodies and are therefore susceptible to infection.
First line serology testing will indicate current active B19V infection. However, when serological test results are negative but infection is still suspected, clinicians can rapidly confirm diagnosis using the new, highly sensitive, Iam Parvo molecular assay. This confirmation is particularly important in the 8 – 12 week period after maternal infection, when the sensitivity of IgM antibody detection varies from 63% to 70% and serological testing alone may not give the full picture[3,4]. Rapid diagnosis of infection allows the foetus to be monitored and appropriate care referrals to be made.
“Iam Parvo is a molecular assay that, when used together with serological testing, enhances the clinical management of B19V-complicated pregnancies,” said Paul Eros, Global Vice President Molecular, DiaSorin. “With this molecular assay launch we underpin DiaSorin’s leadership in Parvovirus B19 testing and demonstrate our commitment to providing a complete diagnostic solution for this important infectious disease. Iam Parvo is the latest addition to the unique and rapidly expanding DiaSorin Q-LAMP assay portfolio for our Liaison® Iam molecular instrument, a benchtop device which meets the needs of laboratories by providing them with a cost-effective, scaleable, molecular diagnostic solution.”
Calibrated against the WHO standard for B19V, Iam Parvo provides exceptional time-to-result benefits when compared to PCR, with equivalent specificity. The Liaison Iam instrument uses DiaSorin’s proprietary Q-LAMP technology.
“People should not confuse DiaSorin Q-LAMP with conventional LAMP technology”, continues Eros, “DiaSorin Q-LAMP assays provide many advantages. They are rapid, real-time, fluorescent, quantitative/qualitative assays designed to be used for multiplexed applications, enabling amplification and detection of multiple targets in a single reaction”.
The Iam Parvo assay is CE-IVD validated for use outside of the USA and Canada only.
1. Dijkmans A.C. et al. Parvovirus B19 in pregnancy: prenatal diagnosis and management of fetal complications. Curr. Opin. Obstet. Gynecol. (2012) 24:95-101.
2. Rohrer C., Gartner B., Sauerbrei A. et al. Seroprevalence of Parvovirus B19 in the German population. Epidemiol. Infect. (2008), 36:1-7
3. Bredl S., Plentz A., Wenzel J.J. et al. False negative serology in patients with acute Parvovirus B19 infection. J. Clin. Viro. (2011) 51:115-120
4. Enders M., Helbig S,, Hunjet A. et al. Comparative evaluation of two commercial enzyme immunoassays for serodiagnosis of gestational Parvovirus B19 infection. J. Virol. Methods (2007) 146:409-413).
Parvovirus B19 infection is common and occurs worldwide. The virus is typically acquired in childhood when it causes the mild, self-limiting rash illness erythema infectiosum (or “fifth disease”). It is transmitted through respiratory droplets and can vary in severity from asymptomatic to life-threatening.
In addition to being a concern in pregnancy, Parvovirus B19 infection is also problematic in immunocompromised patients and is the leading cause of pure red cell aplasia in AIDS patients. In individuals with sickle cell anaemia infection can result in transient aplastic crisis (TAC). Chronic infection can lead to persistent and severe anaemia and is also associated with conditions such as arthropathy, glomerulonephritis and neurological disease.