Diagnostic Performance of Salivary PCR for the Detection of Congenital Cytomegalovirus: A Systematic Review and Meta-Analysis.

Congenital cytomegalovirus (CMV) is a major cause of neonatal morbidity, particularly sensorineural hearing loss, yet its early detection remains challenging. While urinary PCR is the current diagnostic gold standard, its implementation in neonatal settings is often limited by feasibility issues. Salivary PCR presents a more practical alternative, but its diagnostic accuracy has remained uncertain. This systematic review and meta-analysis aimed to evaluate the performance of salivary PCR compared to urinary PCR in detecting congenital CMV in neonates. Following PRISMA guidelines, 15 observational studies involving 29,617 neonates were analyzed using a random-effects model. Pooled sensitivity and specificity were 0.99 and 1.00, respectively, with a negative predictive value (NPV) of 1.00 and a positive predictive value (PPV) of 0.91, despite moderate heterogeneity. Subgroup analysis showed high diagnostic performance across general neonates, infants of seropositive mothers and high-risk neonates (referring to neonates that are small for their gestational age (SGA), neonates who failed hearing screening, and neonates with CMV-related congenital abnormalities). The general group had the highest specificity (0.999), while high-risk neonates showed the highest sensitivity (0.981). Across all groups, NPV remained consistently above 0.994, with PPV ranging from 0.848 to 0.981. These findings confirm that salivary PCR is a highly accurate and feasible tool for congenital CMV diagnosis.