Progress has been made in screening infants for hearing loss but many are not receiving follow-up diagnostic and intervention services, U.S. officials say.

The Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report released Thursday said congenital hearing loss affects two to three infants per 1,000 live births and when left undetected it can result in delays in children's speech and language development.

All states and U.S. territories have established Early Hearing Detection and Intervention programs, which help ensure that infants are screened for hearing loss and receive recommended follow-up diagnostic and early intervention services, the report says.

"A number of infants are not receiving recommended follow-up diagnostic and intervention services," the report says. "This is why efforts are currently under way to enhance Early Hearing Detection and Intervention surveillance systems to capture more complete data and increase education and outreach efforts to families and providers about the importance of receiving recommended follow-up services."