Frequently Asked Questions About Cytomegalovirus Disease (CMV)

When CMV causes an infection for the first time, it is called a primary infection. Just as with all infections, the body begins to fight CMV by producing antibodies and immune cells. While there is an active infection in the body, CMV will be excreted or shed in body fluids. After infection, however the virus remains in the body in a latent or inactive state, usually for life. CMV antibodies will be present for life as well. Like other viruses in its family, CMV can reactivate (act like a new infection). This type of infection is a recurrent infection and may occur at any time, but especially when the immune system becomes altered or weakened. When reactivation occurs, CMV antibody levels may increase and viral shedding may reoccur.

When a person is infected with CMV any time after birth, it is known as an acquired infection. In normally healthy children and adults, CMV infection is usually not a concern. Ninety percent of the time it will not produce any signs or symptoms of infection. However, occasionally a flu-like or mononucleosis type of illness may occur and produce symptoms such as fever, sore throat, fatigue and swollen glands. In persons with a weakened immune system, such as patients who are infected with HIV, organ/bone marrow transplant recipients, chemotherapy/radiation patients, and people on steroid therapy, the signs and symptoms of CMV infection can be serious. Signs and symptoms can occur when an old CMV infection reactivates or when the person catches the virus for the first time. CMV infection in people with a weakened immune system puts them at risk for pneumonia, retinitis (an infection of the eye that can cause blindness), hepatitis (inflammation of the liver), esophagitis and colitis (gastrointestinal diseases), meningoencephalitis (an infection of the brain and the fluid that surrounds it), and even death.

CMV is the most common congenital infection that is passed from mother to unborn baby. Of the estimated four million infants born each year in the United States, approximately one percent will be congenitally infected with CMV. Most (90 percent or about 36,000 infants each year) of the congenitally infected infants will be symptom-free; however, the remaining ten percent (about 4,000 infants each year) may have one or multiple abnormalities.

The diagnosis of congenital CMV infection is confirmed by isolating (growing) the virus from urine, saliva, or tissue that is collected during the baby's first three weeks of life. Urine usually is tested because it contains the highest concentration of the virus. A positive viral culture collected beyond the three-week period but within the first year of life should be considered a possible congenital CMV infection, but also may be an acquired CMV infection. The three-week period is important because after this time CMV can be isolated from babies that were infected during delivery or just after birth (for example, through breast milk). Unlike congenitally infected babies, most infants who acquire CMV during or after birth do not appear to be at risk for physical and mental disabilities.

Signs and symptoms of congenital CMV infection that are observed at birth include small head size (microcephaly), small body size, little red spots under the skin (petechiae), enlarged liver (hepatomegaly), enlarged spleen (splenomegaly), yellow color of skin and eyes (jaundice), low blood count (anemia and/or thrombocytopenia), pneumonia, seizures, abnormal muscle tone, calcium deposits in the brain (intracranial calcifications), vision loss, and hearing loss. Although some of these conditions may resolve, many children will have life-long disabilities of varying degrees. Possible disabilities associated with congenital CMV disease are deafness, blindness, physical and motor impairment, seizure disorder, developmental differences and learning delays.

The majority of infants born with congenital CMV infection have a "silent" or symptom-free infection. Because these infants have no symptoms or abnormalities due to CMV at birth, the infection often goes unnoticed and undocumented. Unfortunately, they do not go totally unharmed by the CMV infection. Between 10-15 percent of all children born "silently infected" with CMV will develop varying degrees of hearing loss shortly after birth or during childhood. It is possible these children also may rarely experience vision problems or developmental and learning differences.

The effect of CMV on the unborn baby may be serious when a woman catches the virus for the first time while she is pregnant. Between one percent and four percent of healthy women will catch CMV for the first time while they are pregnant (primary infection). Fewer than half (about 40 percent) of these women will pass the virus to the fetus, and only ten percent of the infected infants will have symptoms or abnormalities at birth. Almost always less severe are congenital CMV infections caused by a mother's recurrent CMV infection. When a woman previously infected with CMV becomes pregnant, it is possible for her to pass the virus to her unborn child through a recurrent infection. However, fewer than one percent of pregnant women who have CMV prior to pregnancy may experience a recurrent infection, and fewer than one percent of those recurrent infections will result in a baby being born with problems associated with CMV infection.

As with any newborn, regularly scheduled follow-up visits with the child's primary pediatrician or family doctor are advised. At birth, he or she should have baseline laboratory tests to determine what organs in the body have been affected by the virus. These tests include complete blood count, platelet count, and liver function tests. If laboratory results are abnormal, follow-up testing should be conducted. Also at birth, to see if the virus has damaged the central nervous system, children with congenital CMV infection should have a computerized tomography (CT) scan of the brain, an eye exam by an ophthalmologist, and a hearing test. Thereafter, at least annual hearing and visual exams are recommended. Because a child with congenital CMV infection may have special needs, her or his growth and development should be followed carefully. Also, unless there is a specific contraindication known, children with congenital CMV infection should receive the routine immunizations recommended for all children.

A child born with probable or confirmed CMV infection should have a hearing test done shortly after birth. Sometimes when a hearing test is warranted, a hearing screen is performed. Although a hearing screen is better than no test at all, a comprehensive hearing evaluation called acoustic brainstem response is the preferred testing instrument for infants and small children. An ABR is a reliable hearing test that is performed by an audiologist. Ask your pediatrician or family practitioner to help you schedule an appointment for the test. It is important to have your child's hearing checked as soon as possible. Early detection of a hearing impairment is vital so that intervention and referral can be made as needed. Children with hearing loss are at risk for delayed speech and language development. Early identification of any hearing loss and appropriate intervention will help to ensure that your child has every opportunity to reach his or her full potential and has the best quality of life.

The most common disability associated with congenital CMV infection is hearing loss that is almost always progressive (worsens over time). Therefore, careful follow-up with an audiologist annually is recommended to monitor for changes. Early detection of hearing loss and proper intervention improves a child's ability to keep pace with developmental milestones, especially language development. Children with a significant hearing loss may benefit from hearing aids or other devices (check with an audiologist). Unfortunately, there is no medical treatment available at this time to prevent or lessen the effects of the hearing loss associated with congenital CMV infection. Cochlear implants (a mechanical device surgically inserted into the inner ear to help hearing) are available for some children with deafness due to congenital CMV.

CMV is a common virus that is shed by many young children, not just those who have congenital CMV infection. Most children who are congenitally infected with CMV will shed the virus through toddler and preschool ages. Infants and children who acquire CMV after the newborn period also may shed CMV for a prolonged period of time. The virus will affect each child differently, and the length of viral shedding may vary. Viral shedding can range from just a few months to eight years of age, and possibly longer. It is not necessary to routinely determine if your child still has the virus active in the urine or saliva because its presence does not appear to influence or predict problems. Furthermore, schools, teachers, and therapists should not require your child to be tested for CMV shedding before being accepted into a program. And they may not deny your child access to education because of the diagnosis of congenital CMV infection.

Every woman of childbearing age should consider knowing her CMV status. Prior to becoming pregnant or early as possible during your pregnancy, consult your doctor to have a blood sample drawn and a CMV antibody test performed. If results are positive for CMV IgG antibody, you most likely have had CMV sometime before in your lifetime. A positive CMV IgG antibody result rarely means you are experiencing a new infection. A CMV IgM antibody test may help distinguish between a new or recent infection (IgM-positive) or an old infection (IgM-negative). Since most women may have a positive CMV IgM antibody response for at least 4 to 6 months, and some for as long as a year or more, if you have both CMV IgG antibody and CMV IgM antibody, then a third test, called the CMV IgG avidity index may be helpful in determining if your CMV infection occurred less than 4 months ago. And depending on the time during your pregnancy your blood was drawn, the CMV IgG avidity index may help determine if your CMV infection occurred during your pregnancy or just prior to your pregnancy. If, on the other hand, the original CMV IgG antibody test result is negative, you have no CMV antibodies; and thus, you are susceptible to catching the virus for the first time. In this case, it is wise to practice the precautionary measures (see Precautions and Preventions) that may reduce your risk of catching CMV during your pregnancy

The risk of delivering a second child with congenital CMV disease is remote. It is possible for your previous CMV infection to become active like a new infection again (recurrent infection). However, in healthy pregnant women, recurrence does not pose the same risk for serious disease in the newborn as does a primary or first-time CMV infection. If you have previously had the virus, your body has antibodies against CMV which, along with other immune factors, appears to protect the fetus from serious illness due to CMV infection.

CMV infections are common in toddlers and preschool age children, and the virus frequently is transmitted in family or group day-care settings. In fact, most people will experience a CMV infection at sometime. However, there are special times, such as during pregnancy, when CMV infections should be avoided, if possible. The spread of the virus can be controlled by practicing good hygiene techniques. The "Universal Precautions" practiced by health professionals and others who come in contact with body fluids are sufficient to prevent transmission of CMV. Although no actions can totally eliminate all risks of catching CMV, precautionary measures that can be taken to help control the spread of infection in the home and other settings include: -Do not kiss children younger than 5 or 6 years of age on the mouth or cheek. Instead, kiss them on the forehead or the top of the head and give them a big long hug. -Do not share food, drinks, or items such as utensils or toothbrushes with young children. -Do wash your hands with soap and water after changing diapers or after having contact with a child's saliva. -Day-care center workers also may wear gloves when changing the diapers of young children. -Because young children, especially toddlers, frequently put toys in their mouths, toys should be washed with soap and water or wiped with a solution of one-part chlorine bleach to nine-parts water, followed by a tap water rinse.

There is no licensed vaccine against CMV at this time. However, research is being conducted on the safety and effectiveness of different experimental CMV vaccines.

There are now several antiviral medications licensed for the treatment of serious CMV disease. The two antiviral medications evaluated in clinical trials and recommended by CMV experts are ganciclovir and valganciclovir. Antiviral treatment should be considered for newborns with congenital CMV disease, and started in the newborn with signs and symptoms associated with congenital CMV within the first month of life, or as soon as possible after diagnosis is confirmed. Ganciclovir is administered intravenously (IV) for usually 6 weeks of treatment. Side effects of IV ganciclovir include irritation at the site of the IV (therefore usually a central line is used to administer the medication safely), and abnormalities in the blood count, especially neutropenia or low infection fighting cells. This side effect may occur in about two thirds of newborns who receive this IV treatment. Occasionally, other bone marrow suppression can occur or a mild drug induced hepatitis has been seen in some children. These side effects are managed by halting the medication temporarily, rechecking the abnormal tests, and restarting the medication when the effects have resolved. Valganciclovir (Valcyte) is administered orally by mouth for usually 6 months of treatment. Side effects of oral valganciclovir include mild upset of the gastrointestinal tract, mild disruption of sleep patterns, and abnormalities in the blood count, especially neutropenia or low infection fighting cells. This side effect may occur in about one fifth of newborns who receive this oral treatment, much less than IV ganciclovir treatment. It is important to make sure the original Valcyte clear solution is provided by the pharmacist and given to your baby. In pharmacy compounding of Valcyte tablets to make a compounded suspension is no longer recommended. Clinical research trials may also be in progress to determine if longer antiviral treatment or new antiviral treatments help babies with severe disease at birth due to CMV infection. You may contact your doctor, www.clinicaltrials.gov, or the Congenital CMV Research, Clinic and Registry program here in Houston Texas for the names of participants near you who may be knowledgeable in treatment of congenital CMV infection.

Prenatal treatment of congenital or in utero CMV infection in the fetus may be administered to the pregnant woman who has experienced a primary CMV infection. If transmission of CMV to her fetus has already occurred and documented by amniocentesis, symptoms of in utero CMV may be lessened or reversed through administration of CMV hyperimmune globulin to the mother. This treatment should be discussed with your doctor, and administered, if considered appropriate for your case, by an obstetrician or maternal fetal medicine specialist familiar with the risks and benefits of this treatment. Administration of CMV hyperimmune globulin to the pregnant mother who has experienced a primary CMV infection during pregnancy but who has not yet been documented to have transmitted CMV to her fetus, may also reduce the risk of CMV transmission to the fetus. Clinical trials further evaluating the risks and benefits of this prenatal treatment are being conducted in many countries around the world, and the latest information on a research trial near you may be available at http://www.clinicaltrials.gov.

It is important for you to know you are not alone and that many people can help you and your family. CMV is a misunderstood virus, and the latest factual information about this virus is available for you, your family and friends, teachers, and health professionals. A parent-to-parent support network also has been established. The support network is a list of families from all across the country who have a child with congenital CMV disease. Parents join for a variety of reasons, but they mostly want support and advice from other parents with similar experiences. For more information about CMV, the Parent-to-Parent Support Network, or other services, please contact the National Congenital CMV Disease Registry, or join the Parent Support Network.