CMV is also a herpes virus, and more than 90% of mothers have been infected with CMV during pregnancy. Once it invades the human body, it will exist in the body for a long time or for life, and when the body's immunity is normal, it is often in a state of latent infection; However, if the immune system of the fetus and infants is immature, the child may have noticeable symptoms. The site of CMV infection is age-related, and central nervous system damage and various congenital malformations are common in fetuses with congenital intrauterine infection; Hepatitis and pneumonia are more common in infants and young children; Older children are more likely to be asymptomatic. That is, the younger the age, the more severe the consequences of CMV infection.
Neonatal infection with CMV is divided into prenatal infections, i.e., intrauterine infection, intranatal infection, and postnatal infection. Postnatal infections are mainly through contact with the mother's saliva or through breast milk. It can also be contracted through contact with other body fluids, although this infection can be avoided with hand hygiene. Intrauterine infections are often severe, about 10% of them are symptomatic infections, which can affect multiple organs and systems, mainly including developmental delay, liver damage, hematologic diseases, pneumonia, central nervous system infection or developmental malformations. Infection at birth and after birth does not cause malformations, neurological damage, hearing damage, etc.
The prognosis of acquired CMV infection is generally good, but not all symptomatic children with congenital CMV infection will have sequelae, and about 1 3 neonates with symptomatic congenital CMV infection have normal developmental outcomes; Not all congenital CMV infections that are asymptomatic at birth have normal developmental outcomes. Factors associated with abnormal neurodevelopmental outcomes are microcephaly and brain imaging abnormalities; Normal brain imaging and normal head circumference are indicative of a positive cognitive outcome. The incidence of hearing loss is about 10% to 15% in all children with congenital CMV, and the incidence of hearing loss in children with symptomatic congenital CMV infection in the neonatal period can be as high as 30% to 65%. Sensory hearing loss associated with CMV can occur at birth or as late as childhood, so neonatal hearing screening can only detect some children with hearing impairment.
Due to the relatively common nature of CMV infection, there is a lack of effective methods to prevent mother-to-child transmission. Infection with this virus is predominantly ganciclovir anti-infective** and may have limited improvement in neurodevelopmental abnormalities.