Cytomegalovirus (CMV) - Symptoms 

The symptoms of cytomegalovirus (CMV) differ depending on whether you have:

• primary CMV - where someone develops a CMV infection for the first time
• re-infection with CMV - an infection with a different strain of virus
• reoccurring CMV - a previously inactive CMV infection is reactivated, often because the immune system (the body’s natural defence against infection and illness) is weakened
• congenital CMV - a CMV infection develops when a woman is pregnant and infects the unborn baby 

Primary CMV

Most cases of primary CMV cause no noticeable symptoms. If you do experience symptoms, they will be similar to flu symptoms and can include:

• a high temperature of 38C (100.4F) or above
• extreme tiredness
• sore throat
• swollen glands
• muscle and joint pain
• loss of appetite

These symptoms should only last for a couple of weeks.

Re-infection with CMV

If you are re-infected with a different strain of the CMV virus, you may not have any symptoms, or you may have symptoms that are similar to a primary CMV infection (see above).

Reoccurring CMV

If CMV reoccurs in healthy people, including during pregnancy, it will cause few if any symptoms.

A CMV infection that reoccurs due to a weakened immune system can cause a wide range of symptoms. This is because the virus can quickly spread throughout the body, causing damage to one or more of your organs. In particular, damage can be done to the digestive system, lungs and eyes.

Symptoms of reoccurring CMV include:

• a high temperature of 38C (100.4F) or above
• diarrhoea
• shortness of breath
• large painful ulcers in your mouth and oesophagus (gullet)
• visual disturbances, such as blind spots, blurring and floaters (a black spot or "web" that appears to be floating in your field of vision)
• pneumonia - inflammation (swelling) of the tissue in your lungs
• retinitis - inflammation of the retina, the light-sensitive tissue that lines the back of your eyes
• hepatitis - inflammation of the liver

If you have a weakened immune system and have one or more of the symptoms above, contact your GP or treatment team immediately.

Congenital CMV

Around 9 out of 10 babies born with congenital CMV experience no symptoms at birth. This is known as an asymptomatic congenital CMV infection.

Hearing loss

A small number of babies with asymptomatic congenital CMV may develop some degree of hearing loss over their first few years of life. Loss of hearing can range from mild to total.

The hearing problems can affect just one ear (unilateral hearing loss) or can cause problems in both ears (bilateral hearing loss). Children with bilateral hearing loss are likely to experience difficulties with speech and communication as they get older.

See the Health A-Z topic about Hearing impairment for more information.

Symptoms at birth

One in 10 babies born with congenital CMV have symptoms at birth, including:

• jaundice - yellow-coloured skin and yellowing of the whites of the eyes
• pneumonia
• a rash of small, purplish spots
• an enlarged liver and spleen
• low birth weight
• seizures (fits)

While some of these symptoms can be treated, some babies will develop long-term conditions as a result of the infection. Up to 9 out of 10 babies born with congenital CMV who have symptoms at birth will develop one or more physical or mental disabilities. These include:

• hearing loss
• visual impairment 
• blindness
• learning difficulties
• lack of physical co-ordination 
• epilepsy - a condition that affects the brain and causes repeated seizures