Is saliva as reliable as urine for detection of cytomegalovirus DNA for neonatal screening of congenital CMV infection?

There are no studies on the detection of cytomegalovirus (CMV) DNA by molecular methods in the saliva of newborn infants in large scale screening programs. To evaluate the usefulness of saliva as a sample for the neonatal screening of congenital CMV infection as compared to urine when processed by a PCR. Saliva and urine samples were obtained during the first week of life. Both samples were attempted to be obtained from the first 2816 neonates. Subsequently, only saliva was obtained from other 1623 infants. Urine and saliva were processed by DNA-PCR. Confirmation of positive results was done by PCR and virus isolation by 3 weeks after birth. A urine sample was not obtainable from 893/2816 (31.7%) infants. Both saliva and urine samples were obtained from the remaining 1923 infants. Of these, 28 (1.45%) were CMV-infected. There was 99.7% agreement between the results with both samples. CMV excretion was similar when PCR was applied to urine (1.3%) or to saliva (1.2%) samples. Among the subsequent 1623 infants for whom only a saliva sample was planned for screening, 16 (0.98%) were CMV-infected. Saliva samples are as useful as urine for the identification of CMV-DNA in large use for screening programs.