CMV Awareness
Congenital Cytomegalovirus: Why Early Detection and Hearing Follow-Up Matter
Each June, National Cytomegalovirus Awareness Month increases understanding of congenital cytomegalovirus (cCMV) and highlights the importance of early detection.
Congenital cytomegalovirus occurs when a baby is infected with CMV before birth. cCMV is the most common infectious cause of birth defects in the United States and a leading cause of non-genetic sensorineural hearing loss in children. About 1 in 200 babies is born with cCMV. Of those babies, about 1 in 5 will have birth defects or other long-term health problems, including hearing loss, vision impairment, developmental delays, and learning difficulties.
Identifying cCMV can be difficult because 85 percent to 90 percent of infants show no symptoms at birth and may pass their newborn hearing screening. However, 10 percent to 15 percent of infants without symptoms later develop hearing loss. Among infants who have symptoms at birth, the risk of hearing loss may be as high as 75 percent.
Hearing loss related to cCMV can begin later, worsen, or fluctuate over time. Children diagnosed with cCMV need ongoing hearing monitoring, even when they initially appear healthy.
Dr. Carly Johnson, director of audiology at South Dakota Services for the Deaf, explains why long-term follow-up matters:
“A baby can pass the newborn hearing screening and still develop hearing loss later on. Any infant diagnosed with cCMV should receive ongoing audiologic follow-up, because early identification and intervention can make a significant difference in a child’s speech, language, and developmental outcomes.”
Families and health care providers can use the Early Hearing Detection and Intervention Pediatric Audiology Links to Services (EHDI-PALS) directory to find pediatric audiologists across the United States.
Infants suspected of having cCMV should be tested within the first 21 days of life. A health care provider may suspect cCMV when a baby does not pass the newborn hearing screening or has signs such as jaundice, microcephaly, low birth weight, seizures, an enlarged liver or spleen, or a rash. Microcephaly means the baby’s head is smaller than expected.
Testing after the first 21 days cannot reliably determine whether the infection occurred before or after birth. Early diagnosis connects families with regular hearing checks, specialist care, and early intervention services.
Contact the South Dakota Newborn Screening Program with questions about cCMV efforts in South Dakota or to connect with health care providers and partners involved in research, education, and awareness.
Email: DOHNewbornScreening@state.sd.us