In these people the infection can cause fever, loss of appetite, hepatitis or pneumonia. In some cases the infection can be very severe or even fatal. CMV can also be dangerous when a pregnant woman is infected with the virus. CMV can cause a variety of disabilities in children whose mothers become infected for the first time during pregnancy. These disabilities may include mental retardation, hearing loss and developmental delay.
Diagnosis is based on finding the virus in urine, saliva, breast milk, cervical secretions or semen.
Newly infected women can spread the virus to their infants during pregnancy, birth or breastfeeding. CMV can be shed in urine or saliva for many months, sometimes for years. An infant who is infected during the first mouth of life may shed the virus for as long as five or six years. Newly infected adults appear to shed CMV for shorter periods. There is no vaccine against CMV and most infected people have no symptoms.