The cytomegalovirus - infection occurs from an environment to a saliva of the sick interlocutor, with a man's seed, allocation from a vagina and other places the virus gets in an organism of the person and gets into a blood. But the immune system kills a virus in a blood, exhausting it in the glands developing a saliva (sialadens) and a tissue of a kidney where the virus passes in an inactive condition and during many weeks and months is not active. The immune system cannot distinguish a sleeping virus.

At men the cytomegalovirus proceeds, as a rule, asymptomatically, or the parotitis - an inflammation of a tissue of testicles is possible. In some cases the inflammation of the urinary channel and unpleasant sensations is observed at an emiction.

Disease is the most dangerous, if it arises during pregnancy. The becoming infected of a fetus conducts in rare cases to accident: on a background of disease at the future child the brain can not develop or happen an edema of a brain (hydrocephalus).

The travailled child can suffer a delay of mental development, deafness, an epilepsy, a cerebral paralysis, muscular delicacy.