Congenital cytomegalovirus--time to diagnosis, management and clinical sequelae in Australia: opportunities for earlier identification.

Objectives: To report on the burden of disease in Australian infants with congenital cytomegalovirus (cCMV) infection in the era of neonatal hearing screening and improved diagnostic techniques.

Design, Setting And Participants: National data were collected from across Australia via the Australian Paediatric Surveillance Unit (APSU) with monthly reporting by > 1000 clinicians between January 1999 and February 2009. For each reported case, data on investigations and epidemiological and clinical features were analysed. Detailed clinical reviews were performed on 42 infants in two Sydney tertiary paediatric infectious diseases clinics.

Results: There were 195 infants with cCMV identified, including 126 definite and 69 probable cases. Of these, 175 (90%) were symptomatic and only 15 were treated with antiviral agents. Identification was delayed beyond 60 days of age in 30 cases (15%). During the period of study, neonatal hearing screening was introduced for most Australian infants. Detection of hearing loss increased from 19% of cCMV cases in 1999-2003 to 31% in 2004-2009. Of 42 infants whose cases were reviewed in detail, 33 (79%) had symptomatic disease. DNA detection of CMV, using polymerase chain reaction testing of newborn screening cards, was useful in retrospective identification, and was strongly correlated with the presence of clinical sequelae (15/18; 83%).

Conclusions: Congenital CMV is underdiagnosed, infrequently treated, and often manifests as isolated hearing loss. Delayed diagnoses both before and after the introduction of neonatal hearing screening represent missed treatment and management opportunities and are likely to lead to poorer, life-long outcomes for these children. Retrospective analysis of newborn screening cards for CMV should be undertaken for infants with sensorineural hearing loss, to identify unrecognised cCMV.