Comprehensive evaluation of risk factors for neonatal hearing loss in a large Brazilian cohort.

OBJECTIVES: To determine the incidence and risk factors of hearing loss (HL) in Brazilian neonates. STUDY DESIGN: 11,900 neonates were screened for hearing and congenital CMV (cCMV). Low and high-risk babies who did not pass their hearing screening and infants with cCMV were scheduled for a diagnostic audiologic evaluation. RESULTS: The incidence of HL was 2 per 1000 live-born infants (95% CI: 1-3). HL was higher in high-risk neonates than in low risk babies (18.6 vs. 0.3/1000 live births, respectively). Among infants exposed to isolated risk factors, association of HL with craniofacial abnormalities/syndromes (RR = 24.47; 95% CI: 5.9-100.9) and cCMV (RR = 9.54; 95% CI: 3.3-27.7) were observed. HL was 20 to 100-fold more likely in neonates exposed to ototoxic drugs in combination with cCMV or craniofacial/congenital anomalies. CONCLUSIONS: Strategies for the prevention of cCMV and exposure to ototoxic drugs may decrease the incidence of HL in this population.

Contribution of Congenital Cytomegalovirus Infection to Permanent Hearing Loss in a Highly Seropositive Population: The Brazilian Cytomegalovirus Hearing and Maternal Secondary Infection Study.

BACKGROUND: The exact contribution of congenital cytomegalovirus infection (cCMVI) to permanent hearing loss (HL) in highly seropositive populations is unknown. We determined the contribution of cCMVI to HL and estimated the effectiveness of newborn hearing screening (HS) in identifying neonates with CMV-related HL. METHODS: A total of 11 900 neonates born from a population with ≥97% maternal seroprevalence were screened for cCMVI and HL. cCMVI was confirmed by detection of CMV-DNA in saliva and urine at age <3 weeks. RESULTS: Overall, 68 (0.6%; 95% confidence interval [CI], 0.4-0.7) neonates were identified with cCMVI. Of the 91 (0.8%) newborns who failed the HS, 24 (26.4%) were confirmed with HL, including 7 (29.2%; 95% CI, 17.2-59.3) with cCMVI. Another newborn with cCMVI passed the HS but was confirmed with HL at age 21 days. Of the 62 neonates with cCMVI who underwent a complete hearing evaluation, 8 (12.9%; 95% CI, 6.7-23.4) had HL and most (7/8; 87.5%; 95% CI, 46.6-99.7) were identified by HS. The rate of CMV-related HL was 8 per 11 887 neonates (0.7 per 1000 live births). The prevalence ratio of HL among neonates with cCMVI compared to CMV-uninfected neonates was 89.5 (95% CI, 39.7-202.0). No late-onset cCMVI-related HL was detected during a median follow-up of 36 months. CONCLUSIONS: cCMVI is an important cause of HL in childhood in all settings. Integrating targeted cCMVI screening among neonates who fail a HS could be a reasonable, cost-effective strategy to identify newborns with early-onset cCMVI-related HL.

Seroconversion for Cytomegalovirus Infection During Pregnancy and Fetal Infection in a Highly Seropositive Population: "The BraCHS Study".

We determined the risk of seroconversion in seronegative pregnant women living in a high seroprevalence population. Cytomegalovirus (CMV)-immunoglobulin G reactivity was determined at the 1st trimester in all women and sequentially for seronegative women. A total of 1915 of 1952 (98.1%; 95% confidence interval [CI], 97.4%-98.7%) women were seropositive, and 36 (1.8%; 95% CI, 1.3%-2.6%) were seronegative. Five of the 36-seronegative women seroconverted for a cumulative rate of 13.9% (95% CI, 4.8%-30.6%). Congenital CMV infection was diagnosed in 1 of 36 infants (2.8%; 95% CI, 0.5%-63.9%) born to seronegative women compared with 8 of 1685 (0.5%; 95% CI, 0.2%-1.0%) infants born to seropositive mothers. Even with a high risk of primary infection in seronegative women, most CMV-infected infants were born to women with pre-existing seroimmunity.

Cytomegalovirus Shedding in Seropositive Pregnant Women From a High-Seroprevalence Population: The Brazilian Cytomegalovirus Hearing and Maternal Secondary Infection Study.

Background: Most congenital cytomegalovirus (CMV) infections in highly seropositive populations occur in infants born to women with preexisting CMV seroimmunity. Although essential for developing prevention strategies, CMV shedding patterns in pregnant women with nonprimary infections have not been characterized. We investigated correlates of CMV shedding in a cohort of seropositive pregnant women. Methods: In a prospective study, saliva, urine, vaginal swabs, and blood were collected from 120 CMV-seropositive women in the first, second, and third trimesters and 1 month postpartum. Specimens were tested for CMV DNA by polymerase chain reaction. We analyzed the contribution of the specific maternal characteristics to viral shedding. Results: CMV shedding was detected at least once in 42 (35%) women. Mothers living with or providing daily care to young children (3-6 years) were twice as likely to shed CMV at least once compared to women with less exposure to young children (58% vs 26%; adjusted relative risk [aRR], 2.21; 95% confidence interval [CI], 1.37-3.56). Living in crowded households (≥2 people per room) was associated with viral shedding (64% vs 31%; aRR, 1.99; 95% CI, 1.26-3.13). Sexual activity as indicated by the number of sexual partners per year or condom use was not found to be a correlate of viral shedding. Conclusions: CMV shedding is relatively frequent in seropositive pregnant women. The association between virus shedding and caring for young children as well as crowded living conditions may provide opportunities for increased exposures that could lead to CMV reinfections in seropositive women.

Adverse outcomes of pregnancy-associated Zika virus infection.

The spread of Zika virus to the Americas was accompanied by surge in the number of infants with CNS abnormalities leading to a declaration of a health emergency by the WHO. This was accompanied by significant responses from governmental health agencies in the United States and Europe that resulted in significant new information described in the natural history of this perinatal infection in a very short period of time. Although much has been learned about Zika virus infection during pregnancy, limitations of current diagnostics and the challenges for accurate serologic diagnosis of acute Zika virus infection has restricted our understanding of the natural history of this perinatal infection to infants born to women with clinical disease during pregnancy and to Zika exposed infants with obvious clinical stigmata of disease. Thus, the spectrum of disease in infants exposed to Zika virus during pregnancy remains to be defined. In contrast, observations in informative animal models of Zika virus infections have provided rational pathways for vaccine development and existing antiviral drug development programs for other flaviviruses have resulted in accelerated development for potential antiviral therapies. This brief review will highlight some of the current concepts of the natural history of Zika virus during pregnancy.

Spectrum of disease and outcome in children with symptomatic congenital cytomegalovirus infection.

OBJECTIVE: To evaluate differences in presentation and outcomes in children with symptomatic congenital cytomegalovirus (cCMV) identified on newborn screening (screened group) and those identified based on clinical findings at birth (referred group). STUDY DESIGN: Data on 178 infants with symptomatic cCMV were analyzed. Demographic characteristics, clinical and laboratory findings documented in the nursery, and sequelae data were compared between the screened and the referred groups using χ(2) or Fisher exact test. RESULTS: Two or more clinical findings were detected at birth in 91% of referred infants, and only 58% of screened infants (P < .001). Significantly more children in the referred group had hearing loss compared with screened infants (P = .009). Fifty-one percent of screened children were free of sequelae compared with only 28% of the referred group (P < .003). CONCLUSIONS: Infants with symptomatic cCMV identified based on clinical suspicion have more severe disease at birth and more commonly have sequelae than those identified on newborn screening. Inclusion of referral infants in many previous reports may have overestimated the severity of disease because of selection bias. Defining the complete spectrum of symptomatic disease due to cCMV and providing precise estimates of disease burden can only be gathered from large newborn screening studies.

Congenital cytomegalovirus infection as a cause of sensorineural hearing loss in a highly immune population.

BACKGROUND: The burden of congenital cytomegalovirus (CMV)-associated sensorineural hearing loss (SNHL) in populations with CMV seroprevalence approaching 100% is unknown. The purpose of this study was to assess the rate, associated factors, and predictors of SNHL in CMV-infected infants identified by newborn screening in a highly seropositive maternal population. METHODS: Newborns with positive saliva CMV-DNA that was confirmed by virus isolation in the first 2 weeks of life were enrolled in a prospective follow-up study to monitor hearing outcome. RESULTS: Of 12,195 infants screened, 121 (1%) were infected with CMV and 12 (10%) had symptomatic infection at birth. Hearing function could be assessed in 102/121 children who underwent at least one auditory brainstem evoked response testing at a median age of 12 months. SNHL was observed in 10/102 (9.8%; 95% confidence interval: 5.1-16.7) children. Median age at the latest hearing evaluation was 47 months (12-84 months). Profound loss (>90 dB) was found in 4/5 children with bilateral SNHL while all 5 children with unilateral loss had moderate to severe deficit. The presence of symptomatic infection at birth (odds ratio, 38.1; 95% confidence interval: 1.6-916.7) was independently associated with SNHL after adjusting for intrauterine growth restriction, gestational age, gravidity, and maternal age. Among 10 infants with SNHL, 6 (60%) were born to mothers with nonprimary CMV infection. CONCLUSIONS: Even in populations with near universal immunity to CMV, congenital CMV infection is a significant cause of SNHL demonstrating the importance of CMV as a major cause of SNHL in children worldwide. As in other populations, SNHL is more frequently observed in symptomatic CMV infection.

Human cytomegalovirus reinfection is associated with intrauterine transmission in a highly cytomegalovirus-immune maternal population.

OBJECTIVE: To determine contribution of reinfection with new strains of cytomegalovirus in cytomegalovirus seromimmune women to incidence of congenital cytomegalovirus infection. STUDY DESIGN: In 7848 women studied prospectively for congenital cytomegalovirus infection from a population with near universal cytomegalovirus seroimmunity, sera from 40 mothers of congenitally infected infants and 109 mothers of uninfected newborns were analyzed for strain-specific anticytomegalovirus antibodies. RESULTS: All women were cytomegalovirus seroimmune at first prenatal visit. Reactivity for 2 cytomegalovirus strains was found in 14 of 40 study mothers and in 17 of 109 control mothers at first prenatal visit (P = .009). Seven of 40 (17.5%) study women and 5 of 109 (4.6%) controls (P = .002) acquired antibodies reactive with new cytomegalovirus strains during pregnancy. Evidence of infection with more than 1 strain of cytomegalovirus before or during current pregnancy occurred in 21 of 40 study mothers and 22 of 109 controls (P < .0001). CONCLUSION: Maternal reinfection by new strains of cytomegalovirus is a major source of congenital infection in this population.

Birth prevalence and natural history of congenital cytomegalovirus infection in a highly seroimmune population.

BACKGROUND: The natural history of congenital cytomegalovirus (CMV) infection is scarcely known in populations with high maternal CMV seroprevalence. This study evaluated the birth prevalence, clinical findings at birth, and hearing outcome in CMV-infected children from such a population. METHODS: Consecutively born infants were screened for the presence of CMV in urine and/or saliva specimens during the first 2 weeks after birth. Neonatal clinical findings were recorded, and CMV-infected children were tested to document hearing function during follow-up. A subset of mothers of CMV-infected infants were prenatally tested for the presence of anti-CMV immunoglobulin G antibodies. RESULTS: Congenital CMV infection was confirmed in 87 (1.08%; 95% confidence interval [CI], 0.86%-1.33%) of 8047 infants. Seven infants (8.1%; 95% CI, 3.3%-15.9%) had at least 1 clinical finding suggestive of CMV infection, and 4 (4.6%; 95% CI, 1.3%-11.3%) had >3 findings of systemic disease. Sensorineural hearing loss was found in 5 (8.6%; 95% CI, 2.9%-19.0%) of 58 children tested at a median age of 21 months. Bilateral profound hearing loss was observed in 2 children, and the hearing threshold was >60 decibels in all 5 children with hearing loss, including 2 children born to mothers with probable nonprimary CMV infection. CONCLUSIONS: The results of this large newborn screening study in a population with high CMV seroimmunity provide additional evidence that congenital CMV disease occurs in populations with high seroprevalence rates, with a similar incidence of CMV-related hearing loss to that reported in the offspring of women from populations in developed countries with lower rates of seroimmunity to CMV.

Hearing loss in children with congenital cytomegalovirus infection born to mothers with preexisting immunity.

OBJECTIVE: To define hearing outcomes in children with congenital cytomegalovirus (CMV) infection born to mothers with non-primary CMV infection. STUDY DESIGN: A cohort of 300 children with congenital CMV infection identified by newborn virologic screening at the University of Alabama Hospital and a private community hospital in which the type of maternal infection could be classified constituted the study population. Maternal infections were categorized by analyzing serum samples. Children were followed prospectively and underwent serial audiologic evaluations. RESULTS: The frequency of hearing loss was not different between children born to mothers with non-primary infection (10%) and those with primary infection (11%). Significantly more children in the primary infection group had progressive and severe/profound hearing loss compared with children in the non-primary group. The frequency of bilateral, delayed onset, high-frequency, and fluctuating hearing loss was not different between the 2 groups. The mean age of diagnosis of hearing loss was 39 +/- 53 months for children born to mothers with non-primary infection and 13 +/- 21 months for the primary infection group (P = .16). CONCLUSIONS: Maternal preexisting seroimmunity to CMV does not provide complete protection against hearing loss in infants with congenital CMV infection.

Congenital cytomegalovirus infection: association between virus burden in infancy and hearing loss.

OBJECTIVE: To determine the relationship between the virus burden in infancy and hearing loss in congenital CMV infection. STUDY DESIGN: A cohort of 76 infants with congenital cytomegalovirus (CMV) infection identified by means of newborn virologic screening was monitored for outcome. The amount of infectious CMV was analyzed in urine specimens obtained during early infancy. Peripheral blood (PB) samples obtained during early infancy were available from 75 children and CMV DNA was quantitated with a real-time quantitative polymerase chain reaction. RESULTS: Infants with clinical abnormalities at birth (symptomatic congenital CMV infection) had higher amounts of CMV in urine (P = .005) and CMV DNA in PB (P = .001) than infants with no symptoms. Eight children with and 4 children without symptoms had hearing loss. Among children without symptoms, those with hearing loss had a significantly greater amount of CMV in urine (P = .03) and PB virus burden (P = .02) during infancy than those with normal hearing. Infants with < 5 x 10(3) pfu/mL of urine CMV and infants with < 1 x 10(4) copies/mL of viral DNA in PB were at a lower risk for hearing loss. CONCLUSION: In children with asymptomatic congenital CMV infection, hearing loss was associated with increased amounts of urine CMV and PB CMV DNA during early infancy.