Infection with cytomegalovirus (CMV), a member of the herpes
virus family, is very common. Between 50% and 85% of people in the
United States have had a CMV infection by the time they are 40
years old, according to the Centers for Disease Control and
Prevention (CDC).
Children typically become infected with the virus in early
childhood, especially those in child-care and preschool settings.
CMV infections are rarely serious in otherwise healthy kids and
adults; they usually cause only mild symptoms, if any. When
symptoms do appear, they are similar to those seen in mononucleosis
("mono") and only last a few weeks.
CMV is mainly a problem for certain high-risk groups,
including:
- unborn babies whose mothers become infected with CMV during
the pregnancy
- children or adults whose immune systems have been weakened by
disease or drug treatment, such as organ transplant recipients or
people infected with HIV
Once a person has had a CMV infection, the virus usually lies
dormant (or inactive) in the body, but it can be reactivated. The
virus is more likely to be reactivated - and cause serious illness
- in people who have weakened immune systems due to illness.
Symptoms of CMV Infections
The symptoms of a CMV infection vary depending upon the age and
health of the person who is infected, and how the infection
occurred.
Infants who are infected before birth usually show no symptoms
of a CMV infection after they are born, although some of these
infants can develop hearing, vision, neurologic, and developmental
problems over time. In a few cases, there are symptoms at birth,
which can include premature delivery, being small for gestational
age, jaundice, enlarged liver and spleen, microcephaly (small
head), seizures, rash, and feeding difficulties. These infants are
also at high risk for developing hearing, vision, neurologic, and
developmental problems.
Newborns can also contract CMV infection during or soon after
birth by passing through the birth canal of an infected mother,
consuming breast milk from a mother with the virus, or receiving a
transfusion of blood donated by a person infected with CMV. Most of
these infants show no symptoms of CMV infection, however, a few may
develop pneumonia or other symptoms. Premature and ill full-term
infants who are infected soon after birth are also at risk for
neurologic and developmental problems over time.
Although CMV infections that occur in kids after the newborn
period usually don't cause significant illness, some infants
and young children may develop pneumonia, hepatitis (inflammation
of the liver), or a rash.
Older children and teens who become infected with the virus may
have mononucleosis-like symptoms, including fatigue, muscle aches,
headache, fever and enlarged liver and spleen. These symptoms are
generally mild, and usually last only 2-3 weeks.
In people who have received organ transplants, or in people
whose immune systems are weakened, CMV can cause serious
infections. In people who have AIDS or HIV, CMV infection may
involve the lungs, nervous system, gastrointestinal tract, and the
eye, sometimes causing blindness.
Duration
If symptoms of CMV do appear, how long they last varies
depending on how the infection occurs and the age and general
health of the patient. For example, serious CMV infections before
birth may cause developmental problems that affect a child for a
lifetime. On the other hand, infection in teens may last only 2 to
3 weeks and cause no lasting problems.
How Does CMV Spread?
In the United States, about 1% of infants are infected with CMV
before birth - usually only if the mother has developed a
first-time CMV infection during pregnancy. As discussed above, an
infected mother can pass the virus to her child before, during, or
after birth.
Any person with a new or past CMV infection can transmit the
virus to others, even if he or she isn't showing any symptoms.
But transmission usually requires fairly close contact; the virus
can be spread through saliva, breast milk, vaginal fluids, semen,
urine, and stool. The virus can also be present in blood products
and donated organs, causing infection after a blood transfusion or
organ transplantation.
Among kids, the virus is commonly spread in child-care centers
or preschool settings, where it passes easily through indirect
contact, especially though contaminated toys. Children who are
infected may then spread the infection to their families.
Diagnosis and Treatment
In serious cases of CMV infection, doctors can make the
diagnosis by detecting the virus in a cultured sample taken from a
sick person's throat, urine, blood, or other body tissues or
fluid. Blood is also drawn at different time intervals to measure
levels of certain antibodies. These antibodies are part of the
immune system's response to a CMV infection, and they can
signal that an active CMV infection exists. Special viral
DNA-detecting tests are also sometimes used to diagnosis CMV
infection.
Currently, there is no specific treatment available or
recommended for otherwise healthy people with CMV infection.
In patients where CMV infection can be life-threatening (newborn
infants, organ-transplant patients, and people being treated for
cancer or who have immune disorders such as AIDS), serious CMV
infections may be treated with intravenous (IV) antiviral
medication, usually in a hospital. Oral antiviral medication may
also be used at home once the infection is under control and the
patient is stable. Because these antiviral medicines may have
serious side effects, doctors use them with great caution,
especially in children.
In bone-marrow transplant patients, CMV-immune globulin
(CMV-IVIG) and the antiviral drug ganciclovir given intravenously
can be used to fight CMV infections.
Preventing CMV Infections
Currently, there is no vaccine to prevent CMV infection. For
those who have close contact with children, especially pregnant
women or women who might become pregnant, hand washing is effective
at reducing the risk of infection from exposure to CMV. Not sharing
eating utensils with young kids and avoiding kissing or intimate
contact with CMV-positive individuals is also important.
A mother who has CMV infection shouldn't stop breastfeeding,
as the benefits of breastfeeding are believed to outweigh the risks
of passing CMV to the infant, and the infant is unlikely to develop
any symptoms if infected.
For organ-transplant patients who are at risk of getting CMV
from a transplanted organ, preventive therapies are available.
Blood banks have certain screening and processing procedures that
help to prevent CMV from being passed in blood products.
When to Call the Doctor
Call your doctor if your child has any of these or other
"mono-like" symptoms:
- fever that lasts for several days
- unusual or extreme tiredness
- muscle aches
- headache
If you are pregnant, ask your doctor about your risk for CMV
infection and about how you can help protect your developing baby
from CMV infection before birth.
If your child has had an organ transplant or has HIV, AIDS,
cancer, or any disease that affects the immune system, he or she is
at special risk of CMV infection. Keep in close contact with your
doctor about signs and symptoms to watch for.
Reviewed by:
Steven A. Dowshen, MD
Date reviewed: April 2006