Cytomegalovirus (CMV) is a virus found around the world. It is related to the viruses that cause chickenpox and infectious mononucleosis (mono). Between 50% and 80% of adults in the United States have had a CMV infection by age 40. Once CMV is in a person's body, it stays there for life.

CMV is spread through close contact with body fluids. Most people with CMV don't get sick and don't know that they've been infected. But infection with the virus can be serious in babies and people with weak immune systems. If a woman gets CMV when she is pregnant, she can pass it on to her baby. Usually the babies do not have health problems. But some babies can develop lifelong disabilities.

A blood test can tell whether a person has ever been infected with CMV. Most people with CMV don't need treatment. If you have a weakened immune system, your doctor may prescribe antiviral medicine. Good hygiene, including proper hand washing, may help prevent infections.

Cytomegalovirus (CMV) is a common virus for people of all ages; however, a healthy person’s immune system usually keeps the virus from causing illness.

In the United States, nearly one in three children are already infected with CMV by age five. Over half of adults have been infected with CMV by age 40. Once CMV is in a person’s body, it stays there for life and can reactivate. A person can also be re-infected with a different strain (variety) of the virus. Most people with CMV infection have no symptoms and aren’t aware that they have been infected.

What is cytomegalovirus infection?

Cytomegalovirus (CMV) is a virus found throughout the world that infects between 50 to 80 percent of all adults in the United States by the age of 40. CMV is in the same family of viruses that causes cold sores (herpes simplex virus), infectious mononucleosis (Epstein-Barr virus), and chickenpox/shingles (varicella zoster virus). Most people who acquire CVM as children or adults display no signs of illness or have mild symptoms such as fever, fatigue, or tender lymph nodes. People with a compromised immune system may have more severe forms of infection involving the nervous system.

A hallmark of CMV infection is that the virus cycles through periods of dormancy and active infection during the life of the individual Infected persons of any age periodically shed the virus in their body fluids, such as saliva, urine, blood, tears, semen, or breast milk. CMV is most commonly transmitted when infected body fluids come in contact with the mucous membranes of an uninfected person, but the virus can also pass from mother to fetus during pregnancy.

Is there any treatment?

Since the virus remains in the person for life, there is no treatment to eliminate CMV infection. However, minimizing contact with infected body fluids can decrease the risk of viral transmission between individuals or from mother to fetus. Contact can be minimized by using gloves or other protective barriers when handling body fluids or contaminated materials (such as diapers or tissues), avoiding shared dishes, utensils, and other personal items, and consistent and thorough hand-washing.

Antiviral drugs (ganciclovir and others)can be used to prevent or control the symptoms of CMV infection in immunocompromised individuals or some infants with congenital infection. CMV immunoglobulin may also be used in some patients. Vaccines are in the development and human clinical trial stages, which shows that vaccines may help prevent initial CMV infection or decrease the severity of symptoms.

What is the prognosis?

For most people CMV infection is not a problem. However, two groups of people are at high risk of neurological or other severe symptoms that may lead to long-term effects:

• Unborn infants whose mothers have CMVinfection. CMV is the most common congenital infection in the U.S. Most infants will have no permanent health consequences, but a small number will have at birth or will develop long-term neurological conditions, such as hearing loss, visual impairment, seizures, or disabilities f mental or physical function. The highest risk of these severe effects on the fetus is for women who acquire CMV infection for the first time during pregnancy. The risk is much lower for women who have had CMV infection in the past before pregnancy.
• Immunocompromised individuals. CMV infection may be severe in solid organ or blood cell transplant recipients, people with untreated or end-stage HIV-AIDS, or others with altered immune function. Infection may affect the brain (encephalitis), spinal cord (myelitis), eye (retinitis), or other organs such as the lungs (pneumonia) or intestinal tract (gastritis, enteritis, or colitis). In addition, transplant recipients may develop organ rejection or graft-versus-host disease associated with CMV infection.

Cytomegalovirus, or CMV, is a common virus that infects people of all ages. Once CMV is in a person’s body, it stays there for life and can reactivate. A person can also be reinfected with a different type of the virus.

Most people infected with CMV show no signs or symptoms. That’s because a healthy person’s immune system usually keeps the virus from causing illness.

When a baby is born with CMV infection, it is called congenital CMV. Most babies with congenital CMV infection never show signs or have health problems. However, some babies can have health problems that are apparent at birth or that develop later during infancy or childhood.

Key Facts

• If you are pregnant and get infected with CMV, you can pass the virus to your baby during pregnancy.
• CMV is the most common infectious cause of birth defects in the United States.
• Most babies with congenital CMV never show signs or have health problems.
• Some babies can have hearing loss at birth or can develop it later.
• One out of five babies with congenital CMV will have symptoms or long-term health problems.

CMV and Birth Defects

Cytomegalovirus, or CMV, is the most common infectious cause of birth defects in the United States.

CMV and Pregnancy

There is no way to eliminate your risk of getting CMV, but you may lessen your chances of getting it.

Babies and CMV

Most babies with congenital CMV infection never show signs or have health problems. However, some babies have health problems at birth or that develop later.

Prevention Tips

• Parents and childcare providers can lower their risk of getting CMV by reducing contact with saliva (spit) and urine from babies and young children. Do not share food, utensils, or cups with a child. Wash your hands with soap and water after changing diapers or helping a child to use the toilet.
• Medicines called antivirals might improve hearing and developmental outcomes in some infected babies who show signs of congenital CMV infection at birth.
• Babies with congenital CMV infection, with or without signs at birth, should have regular hearing checks.

People with CMV may pass the virus in body fluids, such as saliva, urine, blood, tears, semen, and breast milk. CMV is spread from an infected person in the following ways:

• From direct contact with saliva or urine, especially from babies and young children
• Through sexual contact
• From breast milk to nursing infants
• Through transplanted organs and blood transfusions

In some cases, infection in healthy people can cause mild illness that may include:

• Fever
• Sore throat
• Fatigue
• Swollen glands

Occasionally, CMV can cause mononucleosis or hepatitis (liver problem).

People with weakened immune systems who get CMV can have more serious symptoms affecting the eyes, lungs, liver, esophagus, stomach, and intestines.

Babies born with CMV can have brain, liver, spleen, lung, and growth problems. The most common long-term health problem in babies born with congenital CMV infection is hearing loss, which may be detected soon after birth or may develop later in childhood.

Blood tests can be used to diagnose CMV infection in adults who have symptoms. However, blood is not the best fluid to test newborns with suspected CMV infection. Tests of saliva or urine are preferred for newborns.

Healthy people who are infected with CMV usually do not require medical treatment. Medications are available to treat CMV infection in people who have weakened immune systems and babies with signs of congenital CMV. For babies with signs of congenital CMV infection at birth, antiviral medications, primarily valganciclovir, may improve hearing and developmental outcomes. Valganciclovir can have serious side effects and has only been studied in babies with signs of congenital CMV infection. There is limited information on the effectiveness of valganciclovir to treat infants with hearing loss alone.

Most people have been infected with cytomegalovirus (CMV), but do not have symptoms. If a pregnant woman is infected with CMV, she can pass it to her developing baby. This is called congenital CMV, and it can cause birth defects and other health problems.

For pregnant women

You can pass CMV to your baby

If you are pregnant and have CMV, the virus in your blood can cross through your placenta and infect your developing baby. This is more likely to happen if you have a frst-time CMV infection while pregnant but can also happen if you have a subsequent infection during pregnancy.

You are not likely to be tested for CMV

It is not recommended that doctors routinely test pregnant women for CMV infection. This is because laboratory tests cannot predict which developing babies will become infected with CMV or have long-term health problems.

You may be able to reduce your risk

You may be able to lessen your risk of getting CMV by reducing contact with saliva and urine from babies and young children. The saliva and urine of children with CMV have high amounts of the virus. You can avoid getting a child’s saliva in your mouth by, for example, not sharing food, utensils, or cups with a child. Also, you should wash your hands after changing diapers. These cannot eliminate your risk of getting CMV, but may lessen the chances of getting it.

For parents

About 1 out of every 200 babies is born with congenital CMV. About 1 out of 5 of these babies will have birth defects or other long-term health problems.

Babies with congenital CMV may show signs at birth

Some signs that a baby might have congenital CMV infection when they are born are:

• Small head size
• Seizures
• Rash
• Liver, spleen, and lung problems

Tests on a baby’s saliva, urine, or blood done within two to three weeks after birth can confirm if the baby has congenital CMV.

Early treatment may help

Babies who show signs of congenital CMV at birth may be treated with medicines called antivirals. Antivirals may decrease the severity of health problems and hearing loss but should be used with caution due to side effects.

Long-term health problems may occur

Babies with signs of congenital CMV at birth are more likely to have long-term health problems, such as:

• hearing loss
• intellectual disability
• vision loss
• seizures
• lack of coordination or weakness

Some babies with congenital CMV but without signs of disease at birth may still have or develop hearing loss. Hearing loss may be present at birth or may develop later in babies who passed their newborn hearing test. Sometimes, hearing loss worsens with age.

Hearing checks and therapies are recommended

Children with congenital CMV should have regular hearing checks. Children with hearing loss should receive services such as speech or occupational therapy. These services help ensure they develop language, social, and communication skills.

The earlier your child can get hearing checks and therapies, the more he or she can benefit from them.