Common Virus is Leading Culprit in Child Hearing Loss, Vaccine Trial Underway at UA School of Medicine

TUSCALOOSA – Cytomegalovirus, commonly known as CMV, is the leading cause of hearing loss in children, as well as the leading infectious cause of brain damage in U.S. children. The University of Alabama School of Medicine, Tuscaloosa, is involved as a satellite site in a CMV vaccine trial and is looking for participants.

Women who recently have delivered a baby at DCH Regional Medical Center or Northport Medical Center, and who have not previously had a CMV infection, are encouraged to participate in the study. A simple blood test will be given to determine status.

CMV is a common virus that infects people of all ages and in all parts of the world. In fact, between 50 percent and 85 percent of adults in the United States will be infected with CMV by age 40 without signs or symptoms.

However, CMV infection is considered a significant public health problem as a herpes-type virus because it can cause disease in unborn babies and in people with a weakened immune system. Other viruses related to CMV include: varicella-zoster virus (VZV), which causes chickenpox and shingles; Epstein-Barr virus (EBV), the cause of infectious mononucleosis; herpes simplex virus (HSV), which causes cold sores and genital ulcers; and human herpes virus 6 (HHV-6), associated with fever and rash in infants and young children.

Each year approximately 40,000 infants born in the United States have congenital CMV infection that has been passed from the pregnant woman to the unborn fetus. Although most of these children will have no apparent damage, 6,000 to 8,000 of them will have central nervous system damage such as hearing loss, mental retardation, cerebral palsy and impaired vision.

There is no effective treatment for congenital CMV infection at this time. Research now is underway to develop an effective vaccine to prevent congenital CMV infection. Dr. Robert Pass, professor of pediatrics and microbiology at UAB, has been involved in congenital CMV infection research for more than 20 years and is the study’s lead investigator.

At the Tuscaloosa satellite site, Dr. Ashley Evans, assistant professor of pediatrics in UA’s College of Community Health Sciences, is the principal investigator, and Dr. Dwight Hooper, assistant professor of obstetrics and gynecology in CCHS, is the co-investigator.

“Congenital CMV is one of the reasons children are born with special needs,” Evans said. “This is the first time an experimental vaccine trial has been held here in Tuscaloosa, and we’re thrilled to be a part of such important research.”

The vaccine is comprised of a protein called glycoprotein B that is part of the envelope or outer coating of CMV. There is no infectious virus in the vaccine. Previous studies with this vaccine have shown that it is safe and well-tolerated.

It is hoped that the study will result in a vaccine that will prevent CMV infection in mothers and their unborn babies. This Phase II clinical trial is sponsored by the National Institute of Allergy and Infectious Diseases. Mothers interested in learning more about this study should call Liz Davis, RN and study coordinator, at 205/348-0780.

How Do You Catch CMV?

Person-to-person contact: The most common way to contract CMV is through person-to-person contact. Children spread CMV to each other and adults through saliva, tears, blood, urine and feces. Several examples of how a person may catch CMV from someone shedding the virus include kissing, sharing eating and drinking utensils and sharing mouthed toys. CMV cannot be spread merely by being in the same room with someone unless bodily fluids are exchanged. There is no information to indicate CMV is transmitted in the air.

Transplants and transfusions: CMV may be spread to organ and bone marrow transplant recipients and to patients who receive a blood transfusion from a donor with an active or past CMV infection.

Mother to newborn baby: CMV commonly is transmitted to newborns through breast milk or by contact with cervico-vaginal secretions at the time of birth. This type of transmission is a natural and usually safe way for a mother to transmit CMV to her healthy, full-term infant because the baby also has the mother’s natural immunity to the virus.

Mother to unborn baby: CMV can be transmitted to the unborn child of a mother with a primary or a recurrent CMV infection.

When a baby catches CMV prior to birth it is known as a congenital CMV infection. Approximately 90 percent of all infants who are infected with CMV prior to delivery are born without symptoms of the virus; however, the remaining 10 percent will have varying degrees of abnormalities.

Can I Prevent Catching CMV?

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 some time. 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 the following good hygiene techniques:

Do not kiss young children under age 5 or 6 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 diaper changes or after contact with a child’s saliva.

Since young children frequently put toys in their mouth, it is recommended the toys 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.