Screening frequency for congenital cytomegalovirus in Flanders, Belgium - a multicentre retrospective study

This study investigates the screening practices for congenital cytomegalovirus (cCMV) in Flanders, Belgium, with the aim of determining the frequency of neonatal screening and the number of diagnoses resulting from it.

Flemish hospitals with maternity facilities were asked for data on the number of infants screened for cCMV (PCR-CMV on saliva or urine), and diagnosed with cCMV (positive PCR-CMV on urine before the age of 3 weeks). Screening and diagnosis rates were compared across geographic regions and screening policies. We defined that at least 3% of neonates should be screened, given the prevalence of common screening indications (i.e. microcephaly and IUGR), and evaluated whether the empirical incidence of cCMV (0.5%) was approached.

Fifty of 57 eligible hospitals participated. Overall, 1.65% of infants were screened and 0.12% were diagnosed with cCMV. Few hospitals screened 3% or more of infants (14/50), and measured an incidence of 0.5% or more (6/50). Hospitals using targeted screening policies conducted fewer screenings (median 1.5% vs 94.2%, p < 0.001) and diagnosed fewer infants (median 0.10% vs 0.54%, p < 0.001) compared to hospitals that screened universally.

There was important variability in cCMV screening practices across Flanders. Most hospitals screened fewer than 3% of infants, i.e. lower than the prevalence of microcephaly, a clinical feature that warrants testing for cCMV. Failure to diagnose cCMV in a timely manner limits the opportunities for early treatment with valganciclovir (secondary prevention) and morbidities such as hearing loss (tertiary prevention). There is a pressing need to enhance the knowledge and vigilance of perinatal healthcare professionals in Flanders, ensuring infants at risk of cCMV are appropriately identified and receive timely care.