Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Cytomegalovirus (pronounced sy-toe-MEG-a-low-vy-rus), or CMV, is a common virus that infects people of all ages. Over half of adults by age 40 have been infected with CMV. Once CMV is in a person's body, it stays there for life and can reactivate. Most people infected with CMV show no signs or symptoms. However, CMV infection can cause serious health problems for people with weakened immune systems, as well as babies infected with the virus before they are born (congenital CMV).