Related Experiment Video
Updated: May 5, 2026
qPCR Is a Sensitive and Rapid Method for Detection of Cytomegaloviral DNA in Formalin-fixed, Paraffin-embedded Biopsy Tissue
Published on: July 9, 2014
Feasibility, performances and predictive value of congenital CMV neonatal screening on saliva swabs
Vincent Portet Sulla1, Barkwendé Kabore2, Rana Rafek2
1Division of Virology, WHO Rubella National Reference Laboratory, Department of Biology Genetics, Paul Brousse Hospital, Paris Saclay University Hospital, APHP, Villejuif, France; INSERM U1184, CEA, Center for Immunology of Viral, Auto-immune, Hematological and Bacterial diseases (IMVA-HB/IDMIT), Paris Saclay University, Fontenay-aux-Roses, France.
Background:
Early diagnosis of congenital CMV infection (cCMVI) allows for early intervention and follow-up to detect delayed hearing loss. While CMV PCR in urine is the gold standard for cCMVI diagnosis, saliva testing is often performed.
Objectives:
Our aim was to determine (i) if swab saliva sampling needed standardization, (ii) if a threshold value in "virus copies per million cells (Mc)" in saliva samples could improve clinical specificity, and (iii) to establish a correlation between viral load in saliva and symptomatology/outcome of cCMVI.
Materials And Methods:
In our institution, universal newborn screening is performed on saliva swabs at delivery or until day 3 of life. If positive, CMV PCR in urine is done within 2 weeks to confirm or exclude cCMVI.
Results:
Cell quantification showed that saliva swab sampling was well performed as 95.4 % samples had more than 100 cells/10 µL. There was a good correlation between saliva viral load in copies/mL and in copies/Mc (Pearson's r = 0.96, p < 0.0001). However, threshold values, established to determine a viral load level at which we could confidently identify infected newborns, did not improve positive predictive value (21.8 % for copies/mL and 21 % for copies/Mc vs 25.4 % without threshold) but instead reduced sensitivity (88 % and 85% vs 100 % without threshold). Samples collected on day 2 or 3 had better positive predictive value (38.7 %) compared to those collected on day 1 (23.8 %). Symptomatology at birth was not significantly associated with viral load in saliva at diagnosis. However, sequelae occurrence was associated with viral load in saliva (copies/Mc).
Discussion:
Our results confirm that saliva swab is a suitable sample for universal neonatal screening. However, identifying newborns that will develop sequelae remains an issue in the management of cCMVI.
