Marisa M. Mussi-Pinhata

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.

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.

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.

Infectious Disease Morbidity Among Young HIV-1–Exposed But Uninfected Infants in Latin American and Caribbean Countries: The National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study

OBJECTIVE. The goal was to describe the frequency, characteristics, and correlates of infectious disease morbidity during the first 6 months of life among HIV-1–exposed but uninfected infants. METHODS. The study population consisted of infants enrolled in the National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study who were HIV-1 uninfected and had follow-up data through the 6-month study visit. Definitive and presumed infections were recorded at study visits (birth, 6–12 weeks, and 6 months). RESULTS. Of 462 HIV-1–uninfected infants with 11644 child-weeks of observation, 283 experienced ≥1 infection. These 283 infants experienced 522 infections (1.8 infections per infant). The overall incidence rate of infections was 4.5 cases per 100 child-weeks of observation. Overall, the most common infections were skin or mucous membrane infections (1.9 cases per 100 child-weeks) and respiratory tract infections (1.7 cases per 100 child-weeks). Thirty-six percent of infants had >1 respiratory tract infection (1.8 cases per 100 child-weeks). Incidence rates of upper and lower respiratory tract infections were similar (0.89 cases per 100 child-weeks and 0.9 cases per 100 child-weeks, respectively). Cutaneous and/or oral candidiasis occurred in 48 neonates (10.3%) and 92 older infants (19.3%). Early neonatal sepsis was diagnosed in 12 infants (26.0 cases per 1000 infants). Overall, 81 of 462 (17.5%) infants were hospitalized with an infection. Infants with lower respiratory tract infections were hospitalized frequently (40.7%). The occurrence of ≥1 neonatal infection was associated with more-advanced maternal HIV-1 disease, tobacco use during pregnancy, infant anemia, and crowding. Lower maternal CD4+ cell counts, receipt of intrapartum antibiotic treatment, and country of residence were associated with postneonatal infections. CONCLUSIONS. Close monitoring of HIV-1–exposed infants, especially those who are anemic at birth or whose mothers have more-advanced HIV-1 disease or who smoked during pregnancy, remains important.

Congenital cytomegalovirus infection in preterm and full-term newborn infants from a population with a high seroprevalence rate.

BACKGROUND Cytomegalovirus (CMV) is the most frequent cause of congenital infections in humans. Prematurity occurs in as many as 34% of infants with symptomatic congenital CMV infection. OBJECTIVE To determine the clinical presentation and frequency of congenital CMV infection among preterm infants and full-term infants from a population with a high seroprevalence rate. DESIGN/METHODS A total of 289 preterm infants (median gestational age, 34 weeks; median birth weight, 1,757 g) and 163 term infants (median gestational age, 39 weeks; median birth weight, 3,150 g) sequentially born were included in the study. Serum IgG antibodies to CMV were measured in all mothers. One urine sample was collected within the first 7 days of age from all newborns. Virus isolation in urine samples was performed by tissue culture, and viral DNA was detected by a multiplex PCR. CMV infection was diagnosed in infants with virus excretion detected by both methods on at least two occasions within the first 3 weeks of life. RESULTS Maternal CMV seropositivity rate was 95.7%. Congenital CMV infection was detected in 6 of 289 (2.1%) (95% confidence interval, 0.84 to 4.68) preterm infants and in 3 of 163 term infants (1.8%) (95% confidence interval, 0.48 to 5.74) (P > 0.05). Four of 6 preterm infants with congenital CMV infection were symptomatic, but none of the term infants was symptomatic (P = 0.16). CONCLUSION The frequency of congenital CMV infection in preterm newborn infants from mothers with a high seropositive rate was similar to that found in term infants. No significant difference was found between the proportion of symptomatic infants among preterm and term infants. Our finding of symptomatic congenital CMV infection underscores the need of further evaluation of correlates of congenital symptomatic infection in highly immune populations.

Usefulness of blood and urine samples collected on filter paper in detecting cytomegalovirus by the polymerase chain reaction technique.

A rapid test for the diagnosis of congenital CMV infection is still needed. This study evaluated the usefulness of dried blood and urine samples collected on filter paper for detecting cytomegalovirus (CMV) by the polymerase chain reaction (PCR) assay compared with the use of liquid urine. Samples were obtained from 332 infants aged 1-7 days. Liquid urine samples were collected into bags, cultured in human fibroblasts, and processed using a multiplex PCR technique. Dried urine samples were obtained by placing a piece of filter paper in contact with the infants genitals. The heels of neonates were punctured and capillary blood was blotted onto filter paper and dried. Dried blood and urine specimens were analyzed by multiplex PCR and nested-PCR assays. A diagnosis of congenital CMV infection was established by isolating the virus, and by detecting viral DNA in the liquid urine. Of the 332 liquid urine samples collected from 332 neonates, seven (2.1%) were positive for CMV and 325 were negative, by both cell culture and PCR assay. In dried samples, CMV DNA was detectable only with a nested PCR assay. Compared with known CMV infection status, 5/7 (71.4%) neonates were positive for congenital CMV infection using dried blood samples. All 325 uninfected neonates were negative. In the dried urine samples, 4/4 CMV-infected infants gave positive tests, and all 262 uninfected infants were negative. Although further improvements in sample collection and/or processing are still needed, PCR testing on dried urine or blood collected on filter paper is a promising approach in the diagnosis of neonatal CMV infection.

Congenital and perinatal cytomegalovirus infection in infants born to mothers infected with human immunodeficiency virus

OBJECTIVES To determine the rates of congenital and perinatal cytomegalovirus (CMV) infection among infants born to mothers infected with HIV compared with infants born to mothers not infected with HIV from a CMV-immune, low-income population. STUDY DESIGN A total of 325 newborns from CMV-seropositive mothers were enrolled and evaluated for congenital CMV infection (150 infants from HIV+ mothers and 175 infants from HIV- mothers. A total of 101 infants from HIV+ mothers and 33 infants from HIV- mothers were evaluated for perinatal CMV infection. The virus was isolated from urine by culture in human fibroblasts and was detected by polymerase chain reaction at birth and at 15 days and 12 weeks of age. RESULTS Only 13 of 150 HIV+ mothers (8.7%) had an AIDS-defining condition, and none had a late-stage HIV infection. Congenital CMV infection was detected in 4 of 150 (2.7%) infants from HIV+ mothers and in 5 of 175 (2.9%) infants from HIV- mothers (p = 1.00). Perinatal CMV infection was diagnosed in 8 of 101 (7.9%) infants from HIV+ mothers and in 13 of 33 (39.4%) infants from HIV- mothers (p < 0.00001). Most infants (93.9%) from HIV- mothers and only 5.9% of infants from HIV+ mothers were breastfed. CONCLUSIONS CMV coinfection in mothers without advanced HIV disease from a CMV-immune population does not enhance the likelihood of congenital CMV infection. Perinatal CMV transmission from HIV-infected mothers may be decreased by avoiding breastfeeding. Further studies on mothers with late-stage HIV infection are needed.

[Immunological peculiarities of extremely preterm infants: a challenge for the prevention of nosocomial sepsis].

OBJETIVO: Realizar revisao sobre os principais aspectos do desenvolvimento imunologico fetal, salientando a defesa de prematuros extremos contra patogenos bacterianos e descrevendo a situacao atual de intervencoes imunoterapeuticas para a prevencao de sepse hospitalar. FONTES DOS DADOS: Obtiveram-se, por meio de busca eletronica, no banco de dados MEDLINE, artigos publicados nos ultimos 15 anos referentes ao tema, e foram selecionados aqueles que trouxessem informacoes relevantes. SINTESE DOS DADOS: A imunidade de prematuros extremos e deficiente devido a fragilidade da pele, a carencia dos produtos de ativacao do sistema complemento, ao menor pool de reserva de precursores de neutrofilos na medula ossea e a quimiotaxia, aderencia, deformabilidade e atividade enzimatica neutrofilicas reduzidas. Limitacoes adicionais sao detectadas na citotoxicidade de celulas NK, na proliferacao e producao de citocinas dos linfocitos T, na cooperacao entre celulas T e B e na sintese de anticorpos pelos linfocitos B. Ainda nao foram demonstrados beneficios definitivos de intervencoes para incremento da funcao imunologica dessas criancas, tais como o uso de imunoglobulinas endovenosas e de fatores estimuladores de colonias mieloides. CONCLUSAO: Em consequencia a imaturidade de diversos componentes da imunidade, prematuros extremos sao altamente suscetiveis a infeccoes nosocomiais. As possibilidades ainda muito limitadas para a intervencao nesse sistema fazem com que o controle dos fatores extrinsecos sejam essenciais para a prevencao da sepse nosocomial nessas criancas.

Immunogenicity of Hepatitis B vaccine in preterm and full term infants vaccinated within the first week of life

The immunogenicity of a Hepatitis B vaccine was evaluated in 110 neonates (57 full term and 53 preterm) born to Hepatitis B surface antigen (HBsAg) negative mothers. Three 10 microg doses of recombinant Hepatitis B vaccine were administered: the first dose within the first week of life; the second between 1 and 2 months; and the third at 5-7 months of age. Anti-HBs antibody titres were measured 3 months after the third dose. The seroconversion rate in preterm infants (77%; 95% CI=64.7-87.1) was significantly lower than in full term infants (98%; 95% CI=91.6-99.9) while the mean anti-HBs titres among those infants that did seroconvert was lower in preterm (186.6 mIU ml(-1)) than in full term infants (537.5 mIU ml(-1)). More full term than preterm infants showed titres greater than 100 mIU ml(-1) (71.9 and 41.5%, respectively). We conclude that the administration of a recombinant Hepatitis B vaccine shortly after birth is less immunogenic in preterm infants weighing <1800 g at birth than in full term infants. Currently accepted recommendations for post exposure perinatal prophylaxis may be inadequate to protect preterm infants.

Limits and patterns of cytomegalovirus genomic diversity in humans

Significance Human cytomegalovirus (HCMV) is the leading cause of birth defects associated with infections and a leading cause of transplantation failure. This study reveals the patterns and limits of HCMV genomic diversity by performing a large-scale analysis of HCMV sequences sampled from human hosts, identifying the hot and cold spots of variability. We find that the diversity is unevenly distributed across three host compartments and show that HCMV populations of vascular compartments are genetically constrained while enriched for polymorphisms of glycoproteins and regulatory proteins. This work significantly advances our understanding of the genomic diversity of HCMV in humans and has clear implications for the development of therapeutics against HCMV. Human cytomegalovirus (HCMV) exhibits surprisingly high genomic diversity during natural infection although little is known about the limits or patterns of HCMV diversity among humans. To address this deficiency, we analyzed genomic diversity among congenitally infected infants. We show that there is an upper limit to HCMV genomic diversity in these patient samples, with ∼25% of the genome being devoid of polymorphisms. These low diversity regions were distributed across 26 loci that were preferentially located in DNA-processing genes. Furthermore, by developing, to our knowledge, the first genome-wide mutation and recombination rate maps for HCMV, we show that genomic diversity is positively correlated with these two rates. In contrast, median levels of viral genomic diversity did not vary between putatively single or mixed strain infections. We also provide evidence that HCMV populations isolated from vascular compartments of hosts from different continents are genetically similar and that polymorphisms in glycoproteins and regulatory proteins are enriched in these viral populations. This analysis provides the most highly detailed map of HCMV genomic diversity in human hosts to date and informs our understanding of the distribution of HCMV genomic diversity within human hosts.