This study will look at the feasibility and acceptability of testing newborn babies who are referred after their newborn hearing screen for an infection called congenital Cytomegalovirus (cCMV). Around 1 in every 100 to 200 babies is born with this virus, and although most remain well it causes 1 in 5 cases of childhood deafness. Knowing that a baby is infected shortly after birth could have significant benefit since a treatment is now available, but screening programs need to be feasible and acceptable. This study aims to evaluate targeted screening for cCMV by taking samples (saliva and urine) from babies who do not pass their newborn hearing screening. The investigators want to see if we can find a quick, reliable and parentally acceptable way to screen babies who fail their hearing test for this virus.

Inclusion Criteria:

• All infants 'referred' for one or both ears following hospital-based newborn hearing screening in North of Tyne and South West London areas. Babies with other known causes of SNHL (e.g. hereditary) and those admitted to Neonatal Intensive Care Units will be included.

Exclusion Criteria:

• Exclusions to this study will be infants with parents/guardians not willing/able to give informed consent or children known to have congenital CMV by antenatal testing or clinical features of CMV infection at birth.

This population this study examines is infants in Newcastle and South West London who are referred for more hearing tests after their neonatal hearing screen.

This cohort of patients will be offered screening tests for congenital CMV infection.