Congenital CMV infection in a Brazilian neonatal intensive care unit: high prevalence among twin newborns.

BACKGROUND: Cytomegalovirus (CMV) is one of the most important pathogens associated with congenital infection worldwide. Most congenital CMV-infected infants are asymptomatic at birth; however, some can develop delayed sequelae, especially hearing loss.

METHODS: This study aimed to investigate the prevalence of congenital CMV infection in a neonatal intensive care unit in a low-income region of Brazil. The objectives extended to identifying associated factors, assessing the clinical status of infected newborns, and undertaking a two-year follow-up to discern potential long-term consequences in the affected infants. This cross-sectional prospective study enrolled newborns up to three weeks of life requiring intensive medical care. We employed a convenience sampling method to include 498 newborns and 477 mothers in the study. Categorical variables underwent analysis employing Fisher's exact test, whereas the examination of continuous variables involved the Mann‒Whitney test.

RESULTS: CMV DNA was detected in saliva/urine samples from 6 newborns (1.21%), confirming congenital infection. We noted a significantly greater incidence (OR: 11.48; 95% CI: 2.519-52.33; p = 0.0094) of congenital infection among twins (7.14%) than among nontwins (0.66%). The twin patients exhibited discordant infection statuses, suggesting that only one of the babies tested positive for CMV. Most of the infected children were born to mothers who initiated sexual activity at a younger age (p = 0.0269). Only three out of the six newborns diagnosed with CMV infection underwent comprehensive clinical assessments and received continuous follow-up until they reached two years of age. Only one of the children had weight and height measurements below the norm for their age, coupled with developmental delays.

CONCLUSIONS: The prevalence of congenital CMV infection among newborns admitted to the NICU was low and similar to that in the general population. However, we found a significantly greater incidence of congenital CMV infection in twins than in singletons. Interestingly, the twin-infected patients exhibited discordant infection statuses, suggesting that CMV was present in only one of the babies. We also found that most of the infected children were born to mothers who initiated sexual activity at a younger age. Diagnostic accessibility and comprehensive surveillance programs are imperative for effectively managing and preventing congenital CMV infections.