ABSTRACT
BACKGROUND: Diagnosis of congenital viral infection at birth is generally attempted by direct detection of the virus by PCR in various neonatal materials. How to reliably diagnose intrauterine infection with parvovirus B19 (B19â¯V) at birth is unknown. OBJECTIVES: To evaluate the performance of B19â¯V DNA detection in cord blood (CB) or neonatal dried blood spots (DBS) in diagnosing fetal infection. STUDY DESIGN: Two cohorts of children diagnosed prenatally with an intrauterine B19â¯V infection were included in this study. CB samples of intrauterine B19â¯V infections that were sent to a reference laboratory for congenital infections in Stuttgart, Germany in the period 1995-2014 were tested in triplicate for B19â¯V DNA by quantitative PCR. DBS from children with intrauterine B19â¯V infection that underwent IUT at the LUMC, Leiden, the Netherlands in the period 2009-2014 were tested for B19â¯V DNA by quantitative B19â¯V PCR in triplicate. RESULTS: Fourteen of twenty (70 %) CB samples tested positive for B19â¯V DNA. The positivity rate was 40 % (4/10) in those with a prenatal diagnosis <20 weeks gestation. When intrauterine B19â¯V infection was diagnosed thereafter, 100 % (10/10) samples were B19â¯V DNA positive. Of the thirteen available DBS, twelve (92 %) tested positive. Viral load in CB and DBS corresponded inversely with time from fetal diagnosis to birth. CONCLUSION: B19â¯V DNA can be detected in neonatal blood samples of children following intrauterine B19â¯V infection, although the possibility of false-negatives, even in severe infections, should be considered. B19â¯V viral load at birth correlates with timing of infection.
