Cytomegalovirus (CMV) is a common virus. Once infected, your body retains the virus for life. Most people don’t know they have CMV because it rarely causes problems in healthy people.

If you’re pregnant or if your immune system is weakened, CMV is cause for concern. Women who develop an active CMV infection during pregnancy can pass the virus to their babies, who might then experience symptoms. For people who have weakened immune systems, especially people who have had an organ, stem cell or bone marrow transplant, CMV infection can be fatal.

CMV spreads from person to person through body fluids, such as blood, saliva, urine, semen and breast milk. There is no cure, but there are medications that can help treat the symptoms.

CMV does not usually cause symptoms.

Some people get flu-like symptoms the first time they get CMV, including:

• a high temperature
• aching muscles
• tiredness
• skin rash
• feeling sick
• sore throat
• swollen glands

If you do have symptoms, they usually get better without treatment within about 3 weeks.