Cytomegalovirus

Cytomegalovirus (CMV) is a virus related to the herpes virus group of infections. Like herpes, it is inactive at times, but it is an incurable life-time infection. CMV is a major concern if a mother becomes first infected while pregnant.

  • The virus normally produces no symptoms in people who are generally healthy.
  • Symptoms of a CMV infection may look similar to mononucleosis (fever, swollen glands, constant fatigue, tonsillitis, liver malfunction).
  • It is estimated that half of all adults are or have been infected by the time they reach 30 years old.
  • CMV may be a worry for organ transplant recipients, who may have acquired the virus from the donor or may have a reactivation of the infection due to immune-suppression therapy.
  • About 1 to 4 percent of women first become infected while pregnant.
  • Complications from a congenital (present at birth) CMV infection include hearing loss, mental retardation, or epilepsy.

Why is cytomegalovirus harmful?

Most people who have CMV aren’t aware of it because the virus rarely produces symptoms. The biggest concern is for people who have weak immune systems and women who become infected while pregnant.

Over half of women of childbearing age become infected with CMV at least six months before becoming pregnant.

  • There appear to be few risks for complications of CMV for this group, and only a few babies have the infection at birth.
  • These babies appear to have no significant illness or abnormalities.

According to the Centers for Disease Control and Prevention (CDC), about 1 to 4 percent of women first become infected with CMV during pregnancy.

  • With a first infection during pregnancy, there is a higher risk that after birth the baby may have CMV-related complications.
  • About 5 to 10 percent of babies with congenital CMV will have signs of the infection at birth. Of these, over 90 percent will have serious complications including hearing loss, visual impairment, mental retardation, autism, attention deficit/hyperactivity disorder, epilepsy, or sometimes death.
  • Premature babies may be at increased risk for these problems.

Although CMV may be transmitted at delivery or through breast milk, these infections usually do not cause illness in a full-term baby. Premature babies, however, are at greater risk for health complications from CMV transmission through breast milk.

How is cytomegalovirus spread?

  • CMV is found in bodily fluids such as saliva, urine, semen, and others.
  • The virus is easily spread in households and in daycare centers.
  • It can be transmitted to the fetus during pregnancy and to the baby during delivery or in breast milk.

How can I prevent catching cytomegalovirus?

Although an infected person may transmit the virus at any time, proper hand washing with soap and water is effective in removing the virus from the hands.

What are the symptoms of cytomegalovirus?

Most babies with congenital CMV do not have symptoms of the infection at birth. However, each baby may experience symptoms differently. Symptoms may include:

The symptoms of CMV may resemble other conditions or medical problems. Always consult your baby’s physician for a diagnosis.

How does a doctor know my child has cytomegalovirus?

  • Most infections with CMV in the mother are not diagnosed because the virus produces few symptoms.
  • A mother who has had CMV infection before may have antibodies present in her blood stream.

If your baby’s doctor suspects CMV, the doctor may screen your baby’s

  • blood
  • urine
  • saliva
  • liver function
  • hearing
  • brain, via ultrasound

Is there a way to diagnose cytomegalovirus before my baby is born?

  • If the mother has symptoms similar to mononucleosis (fever, swollen glands, constant fatigue, tonsillitis, liver malfunction) while pregnant, she may be given a test to screen for CMV.
  • A prenatal ultrasound can test your baby for symptoms of a CMV infection by allowing your doctor to inspect the brain as well as your baby’s gestational size.

How do we treat cytomegalovirus?

Children with a CMV infection may receive

  • the anti-viral medication ganciclovir
  • CMV-Ig, which contains CMV antibodies from a blood donor.

Data suggests these anti-viral agents can reduce hearing loss, CMV-related hepatitis, and CMV-related gastroenteritis in newborns.

Treatment may be prolonged for infants, but rarely requires lifetime management. Solid organ transplant patients may require lifetime management of CMV, in light of the immune-suppression therapy required to prevent organ rejection.

How Boston Children’s Hospital approaches cytomegalovirus

Because CMV could be a concern for newborn babies, doctors at Boston Children’s believe that diagnosis and treatment are most beneficial when they come early; these may include prenatal screening for infection and administering of anti-viral agents. Researchers are also looking for ways to prevent transmission of CMV from breast milk to pre-term infants, and ways to manage CMV for organ transplant recipients.