gms | German Medical Science

Background: Congenital cytomegalovirus (cCMV) infection is the leading cause of congenital infections worldwide, resulting in neurological, opthalmological, and other findings, most often a hearing loss. Approximately 10% of these infections are symptomatic at birth, 90% are asymptomatic and escape early diagnosis and intervention.Recently, an international cCMV consensus group recommended to consider a universal cCMV screening of neonates. This cohort study, performed in Doha, Qatar, and in the Ruhr area, Germany, examined outcome and feasibility of such a screening, the region-specific prevalence of cCMV infections, and evaluates a follow-up program.

Methods: 12,442 neonates, 6,128, from Germany and 6,326 from Qatar, underwent a CMV-screening with real-time polymerase chain reaction (PCR)-based testing of liquid-saliva specimes obtained from buccal swabs. A cCMV infection was confirmed by the detection of CMV DNA in blood and/or urine of the newborns who failed the screenings. Infected infants were enrolled in a long-term follow-up program.

Findings: 38 babies from Germany and 15 from Qatar were detected with CMV DNA. An infection was confirmed in 18 German and 3 Qatar babies, but was highly probable in at least additional two German and six Qatar babies (high viral load of saliva, but lost to follow-up). These results corresponded to a prevalence of cCMV infections of 0.33% (95% confidence interval [CI] 0.19%-0.47%) in Germany and of 0.14% (95% CI 0.09%-0.19%) in Qatar. The specificity of the screening was 99.7 (95% CI 99.63%-99.77%) in Germany and 99.9% (95% CI 99.86%-99.94%) in Qatar, the sensitivity 100% (95% CI 100%-100%). The positive predictive values of the screenings were 0.52 (95% CI 0.51-0.53) for Germany, and 0.60 (95% CI 0.59-0.61) for Qatar.

Four infected infants showed symptoms: one child was symptomatic at birth (Germany), one (Qatar) had a congenital hearing loss detected by a newborn hearing screening, one (Germany) developed a late-onset hearing loss and additional symptoms during her first year of life, one showed pathological findings in cerebral MRI. The three children with clinical symptoms underwent both antiviral and timely symptomatic treatment with hearing aids and additional rehabilitative measures.

Interpretation: 0.32 per thousand infants of our cohort showed symptoms typical for a cCMV infection at birth or later. The screening and a so far 1-3-year follow-up identified 0.24 per thousand neonates (0.33 for Germany, 0.16 for Qatar) who developed hidden or late-onset symptoms and got timely intervention or who had covert symptoms requiring further monitoring. To detect such children early, a universal neonatal cCMV screening seems recommendable. Our group developed a screening algorithm which enables a stratification of infected infants according to low and high risk of late-onset cCMV symptoms ([1]).