In a study at two hospitals in Jerusalem, 100 of 176 newborns with congenital infection were excluded from screening based on suspicious signs; the decision to routinely screen all newborns still requires a cost-benefit analysis
A baby born with congenital cytomegalovirus (CMV) may appear healthy and even pass a routine hearing test, but in some cases the infection is later associated with hearing or developmental impairment. A study conducted at Hadassah Medical Center in Jerusalem examined what would happen if all participating newborns were screened, compared to an approach in which testing is done only when infection is suspected.
The study by Prof. Dana Wolf, Prof. Smadar Avantov-Friedman, Prof. Moran Yasur and their colleagues was published in the journal The Lancet Infectious Diseases in April 2026, and the Hebrew University issued a press release about it in September. It was conducted from April 2022 to March 2025 at the two Hadassah hospitals in Jerusalem.
More than half of the cases were not referred for targeted testing
The researchers screened 48,556 newborns whose parents agreed to participate, about 94.7% of all births at the two centers during the study period. Congenital CMV infection was confirmed in 176 of them, about 3.6 per 1,000 newborns tested. According to the criteria of an expanded targeted screening — for example, failure of a hearing test, signs of illness, or documentation of maternal infection during pregnancy — 100 of them, or 57% of those diagnosed, would not have been sent for testing at all.
Of these 100 newborns, eight were initially found to have moderate to severe signs and three had sensorineural hearing loss despite showing no other symptoms. Ultimately, 11 of the group received antiviral treatment on medical grounds. These numbers emphasize that a normal hearing test at birth does not rule out congenital CMV, but they do not mean that every newborn who tests positive needs treatment.
Collecting saliva samples
To reduce the testing burden, the researchers pooled saliva samples from several infants and tested them together using PCR. When a pool of samples was positive, the samples were tested individually, and a positive saliva result was confirmed with a urine test. The method reduced the number of laboratory tests required by about 83% compared to testing each sample separately, but the researchers also measured some loss in measurement sensitivity due to the pooling.
Follow-up until age 1 provided information on hearing and development, but some impairments may be detected later. The study was conducted in only two hospitals and did not directly assess the cost-benefit of a national survey. Therefore, the results strengthen the debate about routine screening, but are not conclusive on their own on how it should be implemented in the general population.
Questions and Answers
Can a baby who has had a normal hearing test not carry congenital CMV?
It can. Some children with congenital infection have a hearing test at birth, so this is not a screening test for CMV.
Does every positive finding require antiviral treatment?
No. The decision to investigate, monitor, or treat depends on the newborn's condition and the assessment of the medical team.
What was the benefit of the merger?
It reduced the number of PCR tests required for the survey by about 83% compared to testing each sample separately, while requiring confirmation of a positive result with a urine test.
The scientific article
Source: Announcement from the investigating institution.
One response
Optimal pooling and finding sensitive methods such as digital swabs and herpes-specific viral DNA extraction from the matrix (saliva) will allow for cost optimization. One should not aim for 100% success, one should aim for a cost-benefit point that justifies itself. Later, as metadata accumulates on subjects without the signs that came out positive, it may be possible to refine the indications against new parameters and reduce the target population.