[Congenital cytomegalovirus infection--clinical characteristics including prenatal diagnosis]

Congenital infections are the important cause of morbidity and mortality of newborn infants. Among them, cytomegalovirus (CMV) infection is the frequent congenital injection worldwide with the incidence 0.3-2.2% of live births. The virus can be transmitted to the foetus through primary (in 30 to 40%) or secondary (rare) maternal infection. 90% of infants with congenital infection have no signs or symptoms at birth. The other 10% will be symptomatic and about half of the will have the classic stigmata of CMV inclusion disease. Ten to thirty percent of the severely affected infants will die, more then 90% of survivors will have neurological handicaps, sensorineural hearing loss, chorioretinitis. Ten to 15% of children asymptomatic at birth have a risk of abnormal development and 10% develop hearing loss during the first years of life. Prenatal detection of congenital disease by ultrasound examination is not sufficient, but prenatal diagnosis can be confirmed by amniocentesis (culture of amniotic fluid and detection of virus DNA by quantitative polymerase chain reactions). However, the number of mothers who underwent amniocentesis and the broad case definition used to define symptomatic disease is still not adequate. Because there is currently no treatment for prenatal infection, early diagnosis of congenital infection during neonatal period is important (the possibility of antiviral treatment of children with symptomatic congenital disease and long-term follow-up). The best hope for eliminating congenital CMV infection is to prevent prenatal infection: with no vaccine, good hygiene and handwashing should be promoted.