Universal neonatal cytomegalovirus screening using saliva - report of clinical experience

To analyze the results of a neonatal universal screen for congenital cytomegalovirus (CMV) using saliva real-time polymerase chain reaction (rt-PCR).

During one year (15/5/2011-15/5/2012), saliva was collected from 9845 infants (97% of 10,137 newborns). Viral DNA was extracted by Magna-Pure LC (Roche) and was tested for the presence of CMV IE and gB genes. Urine culture was collected from positive infants for confirmation. For all infants with congenital CMV maternal data were collected and head ultrasound, blood count, liver enzymes, retinal examination and auditory brainstem response testing were performed. Parents were notified in advance and had the option to avoid screening. The ethical committee approved retrospective analysis of the data.

Fifty six infants (0.57%) had a positive saliva assay. Of these, 47 were confirmed by urine rt-PCR and culture, in another one maternal sero-conversion was documented during pregnancy (48 infants). Twenty-eight mothers (28/47, 60%) had primary infection during pregnancy, 14 (30%) had non-primary infection, and no serological data were obtained from five (10%). Four infants (8.5%), two with prenatal diagnosis of CMV and normal fetal brain imaging and two born to mothers sero-positive before pregnancy, exhibited symptoms related to CMV and were offered antivirals. Hearing impairment was diagnosed in two infants (late onset HI in one case).

Saliva rt-PCR assay is a feasible and effective means of universal neonatal CMV screening that can detect affected infants who might benefit from treatment and follow-up. The long-term clinical significance of screening and its cost effectiveness are yet to be determined.