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Introduction: Neurogenic bladder was first confirmed as a urological sequela of Congenital Zika Syndrome (CZS) in 2018. Further clinical-epidemiological evidence also confirmed neurogenic bowel dysfunction and cryptorchidism. To strengthen the care for these children, the Congenital Zika Virus Bladder and Bowel Sequelae Network (RASZ in Brazilian) was created, including six integrated centers in Brazil. This article represents the initial outcome of the efforts by RASZ., Objective: To evaluate the prevalence of bladder and bowel dysfunction, cryptorchidism and other urological sequelae related to CZS in cohorts attended in six Brazilian states., Study Design: Observational, prospective, multicenter study including children with CZS assisted in one of six RASZ collaborative centers between June 2016 and February 2023. Data were collected from patient's first assessment using the same protocols for urological and bowel evaluation. Categorical variables were analyzed by frequency of occurrence and numerical variables by mean, median, and standard deviation. The study was approved by the Research Ethics Committees of each center, all parents/caregivers provided written informed consent., Results: The study included 414 children aged 2 months to 7 years (mean 2.77 years, SD 1.73), 227 (54.8 %) were male and 140 (33,8 %) referred urological and bowel symptoms on arrival. Prevalence of both urological and bowel sequelae was 66.7 %, 51 % of children aged 4 years and older had urinary incontinence (UI). UTI was confirmed in 23.4 % (two presented toxemia) and among males, 18.1 % had cryptorchidism. Renal ultrasonography, performed in 186 children, was abnormal in 25 (13.4 %), 7 had hydronephrosis. Among the 287 children who performed urodynamics, 283 (98.6 %) were altered: 232 had a lower bladder capacity, 144 a maximum bladder pressure of ≥40 cm H2O, and 127 did not satisfactorily empty their bladder., Discussion: A higher prevalence of NLUTD, neurogenic bowel and cryptorchidism was confirmed in children with CZS. Early diagnosis and appropriate treatment, including a multidisciplinary approach, may reduce the risk of UTIs, UI and kidney damage. A limitation of the study was the inability of children to complete the protocol, specifically urodynamic evaluation, and ultrasonography. In both exams, the percentage of abnormal cases was higher than that expected in the normal population., Conclusion: A 66,7 % prevalence of combined urological sequelae and bladder-bowel dysfunction related to CZS was confirmed in patients evaluated in six Brazilian cohorts. The most frequent changes were related to NLUTD, neurogenic bowel, and cryptorchidism. Prevalence may be underestimated due to access restrictions to diagnostic tests., Competing Interests: Conflict of interest None., (Copyright © 2023 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Chikungunya virus (CHIKV) is an arbovirus (Togaviridae family, Alphavirus genus) that was first identified in 1953 in Tanzania. In 2014, the Asian and East/Central/South/African (ECSA) genotypes were identified in Brazil, although the genotype that spread the most in the following years across the Brazilian territory was the ECSA. The clinical symptoms associated with the infection caused by CHIKV include mainly fever, myalgia, headache, and arthralgia. In infections caused by other arboviruses (such as the ones caused by Dengue and West Nile viruses), changes in biochemical markers are often observed. This study aims to evaluate the biochemical markers profile of kidney and liver injury in acute patients infected with CHIKV. Two groups of correlations were found between the variables analyzed, namely, one between liver enzymes (r = 0.91), and another for kidney markers (r = 0.54-0.66). A significant elevation in the percentage of altered creatinine in CHIKV-infected patients was observed, followed by uric acid and AST. Altogether, in 8 different comparisons, it was possible to observe statistically significant differences between the levels of the markers when compared to the manifestation of symptoms (presence and absence). These noticeable changes in marker measurements could potentially be connected to the range of clinical symptoms seen in the disease., (© 2023 The Authors. Journal of Medical Virology published by Wiley Periodicals LLC.)

Background: Knowledge regarding the risks associated with Zika virus (ZIKV) infections in pregnancy has relied on individual studies with relatively small sample sizes and variable risk estimates of adverse outcomes, or on surveillance or routinely collected data. Using data from the Zika Brazilian Cohorts Consortium, this study aims, to estimate the risk of adverse outcomes among offspring of women with RT-PCR-confirmed ZIKV infection during pregnancy and to explore heterogeneity between studies., Methods: We performed an individual participant data meta-analysis of the offspring of 1548 pregnant women from 13 studies, using one and two-stage meta-analyses to estimate the absolute risks., Findings: Of the 1548 ZIKV-exposed pregnancies, the risk of miscarriage was 0.9%, while the risk of stillbirth was 0.3%. Among the pregnancies with liveborn children, the risk of prematurity was 10,5%, the risk of low birth weight was 7.7, and the risk of small for gestational age (SGA) was 16.2%. For other abnormalities, the absolute risks were: 2.6% for microcephaly at birth or first evaluation, 4.0% for microcephaly at any time during follow-up, 7.9% for neuroimaging abnormalities, 18.7% for functional neurological abnormalities, 4.0% for ophthalmic abnormalities, 6.4% for auditory abnormalities, 0.6% for arthrogryposis, and 1.5% for dysphagia. This risk was similar in all sites studied and in different socioeconomic conditions, indicating that there are not likely to be other factors modifying this association., Interpretation: This study based on prospectively collected data generates the most robust evidence to date on the risks of congenital ZIKV infections over the early life course. Overall, approximately one-third of liveborn children with prenatal ZIKV exposure presented with at least one abnormality compatible with congenital infection, while the risk to present with at least two abnormalities in combination was less than 1.0%., Competing Interests: Declaration of interests We declare no competing interests.

Background: Zika virus (ZIKV) infection can result in hearing loss in babies, consequently, audiological monitoring is necessary., Aims: This study aimed to evaluate the frequency of hearing impairment in neonates and children exposed to ZIKV during the intrauterine period., Materials and Methods: A cohort of 30 children born to mothers infected with ZIKV during pregnancy (March 2016-January 2017) underwent repeated hearing assessments performed 48 h after birth. Universal Newborn Hearing Screening revealed normal results in all children at 6, 13, 24, and 36 months. Children were divided into two subgroups based on real-time polymerase chain reaction: RT-PCR(+) and RT-PCR(-)., Results: At 24 months, the cumulative incidence of hearing alteration was 57.1%. There was no significant difference in the detection of hearing alteration between RT-PCR(+) and (-) groups. None of the children had sensorineural hearing loss., Conclusions and Significance: None of the children had sensorineural hearing loss. Total incidence conductive type (per 1000 live births), RT-PCR ZIKV (-) 2.2, prevalence 20% and RT-PCR ZIKV 3.1, prevalence 35.7%.The incidence of hearing alteration was highest at 24 months of age (57.1%, n  = 8; only conductive type).

Method: This was a prospective, observational, and descriptive cohort study. Nasopharyngeal swabs and blood were collected six times at weekly intervals. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) tests and immunoglobulin (Ig) G and IgA assays were used to test for COVID-19., Results: Overall, 419 children and 253 adults were enrolled. There was a significant correlation between qRT-PCR confirmation and the 1 to <5 years age group ( p =0.038). Serology changes or recent infections were detected significantly in children <6 months (IgG, p =0.006; IgA, p =0.001) and >5 years of age (IgA, p =0.040; IgG, p =0.031). The mean and median time-to-positivity (using qRT-PCR) was 17 days, with a minimum of 6 and a maximum of 34. Among adults, the mean and median time-to-positivity was 12.6 and 9 days, respectively, with a minimum of 6 and a maximum of 45., Conclusion: Oligosymptomatic conditions may delay diagnosis and facilitate viral transmission. Pediatric-focused research is required, and specific protective measures for children <6 months of age should be considered., Competing Interests: The authors declare that there are no conflicts of interest., (Copyright © 2022 Márcia Borges Machado et al.)

In pregnant women, Zika virus (ZIKV) is associated with a congenital syndrome, most frequently involving damage to embryo brain formation and the development of microcephaly. The mechanism(s) by which ZIKV enters the maternal-fetal interface and is transmitted to the fetus remains incompletely determined. We sought to evaluate histologic changes in the placenta of ZIKV-infected pregnant women and to determine if this varied by maternal age. Placental samples were obtained from 66 women, 33 of whom were positive for ZIKV. Histologic evaluations were performed on 4 areas of the placenta: fetal surface, maternal surface, umbilical cord, and membranes. Samples were analyzed by the tissue microarray technique and tested for CD4, CD8, CD20, CD68, FOXP3, and cyclooxygenase-2 expression. Data were evaluated using Fisher exact test. ZIKV infection was more frequent in women less than 18 yr of age (9/11, 81.8%) than in women above 18 yr old (24/55, 43.6%) (P=0.0440). ZIKV detection was associated with neutrophilic chorioamnionitis (P=0.0332) and with septal (P=0.0244) and villous (P=0.0534) calcification. Hofbauer cell hyperplasia (P=0.0260) and cyclooxygenase-2 expression (P=0.0346) were more prevalent in ZIKV-positive women aged 18 yr and below than in the older ZIKV-positive women. ZIKV infection during pregnancy occurs more frequently in adolescents and induces higher rates of damage at the maternal-fetal interface than in older women., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 by the International Society of Gynecological Pathologists.)

During the 2015-2016 epidemic, Brazil was the country with the highest rate of Zika virus (ZIKV) infection in the Americas. Twenty-nine percent of pregnant women positive for ZIKV exhibited ultrasound scans with fetus anomalies. Human leukocyte antigen-G (HLA-G) exerts immunoregulatory effects by binding to inhibitory receptors, namely LILRB1 and LILRB2, thus preventing mother-fetus rejection and vertical pathogen transmission. The binding of HLA-G to one of its receptors modulates both innate and adaptive immunity. However, in a viral infection, these molecules may behave as pathogenic mediators shifting the pregnancy environment from an anti-inflammatory profile to a pro-inflammatory phenotype. Genetic mutations might be associated with the change in phenotype. This study aimed to explore the possible role of polymorphic sites in HLA-G , LILRB1 and LILRB2 in mother-fetus ZIKV transmission. Polymorphisms were detected by direct sequencing. Differences in allele and/or genotype frequencies for each SNP analyzed among ZIKV non-transmitting and transmitting mother-child pairs, among ZIKV-transmitting and non-transmitting mothers and between ZIKV-infected and non-infected children were compared by Mid-P exact test or Yates' correction. Significant susceptibility of ZIKV vertical transmission is suggested in ZIKV-transmitting and non-transmitting mothers and ZIKV-infected and non-infected children for LILRB1&#95;rs1061684 T / T ( p = 0.03, Pc = 0.06, OR = 12.4; p = 0.008, Pc = 0.016, OR = 16.4) and LILRB1&#95;rs16985478 A / A ( p = 0.01, Pc = 0.02, OR = 19.2; p = 0.008, Pc = 0.016, OR = 16.4). HLA-G&#95;rs1710 ( p = 0.04, Pc = 0.52, OR = 4.30) was also a susceptibility factor. LILRB2&#95;rs386056 G / A ( p = 0.02, Pc = 0.08, OR = 0.07), LILRB2&#95;rs7247451 G / G ( p = 0.01, Pc = 0.04, OR = 0.04) and HLAG&#95;rs9380142 T / T ( p = 0.04, Pc = 0.52, OR = 0.14) were suggested as protective factors against vertical transmission. The current study suggests that polymorphic sites in the LILRB1 and HLA-G genes might be associated with mother-to-child ZIKV transmission while LILRB2 might be associated with protection against ZIKV transmission in the womb in a population from the south and southeast of Brazil.

Abstract: The Hammersmith infant neurological examination (HINE) is a highly predictive tool for the easy and low-cost detection of cerebral palsy. Between 2015 and 2016, the rapid spread of the Zika virus (ZIKV) in Brazil was responsible for an increase in microcephaly cases. This study aimed to verify the accuracy of the HINE for the early detection of neurological problems in Brazilian babies exposed to ZIKV.This was a cross sectional case-control study of children exposed to ZIKV. This study was part of the Jundiaí ZIKV Cohort. Of a total sample of 782 children, 98 were evaluated (26 in the exposed group and 63 in the control group). We included late preterm infants and term infants who were exposed to the ZIKV and were participants in the ZIKV Cohort study. Student's t-test and stepwise multivariate logistic regression were used to compare groups.Of the 26 items evaluated in the five scored categories of the HINE (cranial nerve function, posture, movements, tone, reflexes, and reactions), only the difference in ankle dorsiflexion between the exposed and the control groups was statistically significant. However, some items showed a significant trend in relation to the control group.Our results demonstrated the importance of early neurological assessment of infants exposed to ZIKV, even in those without a microcephaly diagnosis., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

The aim of this study was to identify the epidemiological profiles of violence against children, victims, and their aggressors, and their correlations between socioeconomic and demographic factors analyzed before and during the COVID-19 pandemic. This was a cross-sectional, retrospective observational study based on a review of Individual Notification Forms from the Information System for Notifiable Diseases, including child victims of violence, under 18 years, assisted by a pediatric emergency service in Brazil, from 2016-2020. Data were stratified, then statistical analysis was performed using the two-proportion equality test and the Chi-square test, with p < 0.05 and a 95% confidence interval. A total of 609 notifications were analyzed and a prevalence of sexual violence (63.2%) was reported. The prevalent profile of victim was female (76.7%), aged between 2-9 years (38.1%) and 14-18 years (35.6%). The violence occurs in the victim's home (58.9%). The prevalent profile of perpetrator was male (82.4%), young adolescent (59.2%), living as family (64%), mainly the parents (18.4%). No correlation was found between the classified socioeconomic and demographic variables and violence. There was an increase in notifications during the COVID-19 pandemic, compared to the same period in the previous year; self-harm was reported in 59.7% of physical violence in 2020. Prevalence of sexual violence was higher for females, aged between 2-9 and 14-18 years, victimized in their homes, by male offenders, living as family, mainly by their parents. No association was found between child violence and the socioeconomic and demographic.

Rationale: The chikungunya virus (CHIKV) was first isolated in a Tanzanian epidemic area between 1952 and 1953. The best description of the CHIKV transmission during pregnancy can be found in a well-documented epidemic in 2005, in the "La Reunion" island, a French territory located in the Indian Ocean, in which about one-third of the population was infected. Reports of arbovirus infections in pregnancy are increasing over time, but the spectrum of clinical findings remains an incognita among researchers, including CHIKV., Patient Concerns: In this report, it was possible to verify 2 cases exposed to CHIKV during foetal period and the possible implications of the infection on gestational structures and exposed children after the birth., Diagnosis: In both cases, the mothers were positive by laboratory tests in serologic analysis for CHIKV, as ezyme-linked immunossorbent assay (ELISA), plaque reduction neutralisation testing (PRNT) and immunofluorescence (IF); but there were no positive tests in quantitative polymerase chain reaction (qPCR) for mothers or children., Interventions: The exposed children were followed up in a paediatrics clinic in order not only to provide the medical assistance, but also to verify child development and the possible implications and neurocognitive changes caused by gestational infection., Outcomes: There were neurological and developmental changes in one of the children followed up on an outpatient basis. There was an improvement in the neurological situation and symptoms only 3 years and 1 month after birth., Lessons: Based on the cases presented, we can conclude that clinical symptoms of CHIKV maternal infection may occur late in new-borns and can affect their development., Competing Interests: The authors have no conflicts of interests to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Despite great advances in our knowledge of the consequences of Zika virus to human health, many questions remain unanswered, and results are often inconsistent. The small sample size of individual studies has limited inference about the spectrum of congenital Zika manifestations and the prognosis of affected children. The Brazilian Zika Cohorts Consortium addresses these limitations by bringing together and harmonizing epidemiological data from a series of prospective cohort studies of pregnant women with rash and of children with microcephaly and/or other manifestations of congenital Zika. The objective is to estimate the absolute risk of congenital Zika manifestations and to characterize the full spectrum and natural history of the manifestations of congenital Zika in children with and without microcephaly. This protocol describes the assembly of the Consortium and protocol for the Individual Participant Data Meta-analyses (IPD Meta-analyses). The findings will address knowledge gaps and inform public policies related to Zika virus. The large harmonized dataset and joint analyses will facilitate more precise estimates of the absolute risk of congenital Zika manifestations among Zika virus-infected pregnancies and more complete descriptions of its full spectrum, including rare manifestations. It will enable sensitivity analyses using different definitions of exposure and outcomes, and the investigation of the sources of heterogeneity between studies and regions.

Congenital Zika virus (ZIKV) infection may present with a broad spectrum of clinical manifestations. Some sequelae, particularly neurodevelopmental problems, may have a later onset. We conducted a prospective cohort study of 799 high-risk pregnant women who were followed up until delivery. Eighty-three women and/or newborns were considered ZIKV exposed and/or infected. Laboratory diagnosis was made by polymerase chain reaction in the pregnant mothers and their respective newborns, as well as Dengue virus, Chikungunya virus, and ZIKV serology. Serology for toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus, and syphilis infections were also performed in microcephalic newborns. The newborns included in the study were followed up until their third birthday. Developmental delay was observed in nine patients (13.2%): mild cognitive delay in three patients, speech delay in three patients, autism spectrum disorder in two patients, and severe neurological abnormalities in one microcephalic patient; sensorineural hearing loss, three patients and dysphagia, six patients. Microcephaly due to ZIKV occurred in three patients (3.6%). Clinical manifestations can appear after the first year of life in children infected/exposed to ZIKV, emphasizing the need for long-term follow-up.

Recent outbreaks of Zika virus (ZIKV) infection highlight the urgent need to evaluate the efficacy of current public health measures to educate susceptible groups about how to prevent infection, modes of viral transmission, and consequences of infection. We performed a cross-sectional study in the city of Jundiaí, São-Paulo, from March 2016 to August 2017. In 315 high-risk pregnant women we evaluated the rate of ZIKV infection, knowledge of pathways of ZIKV transmission, and the use of protective measures. Data were analyzed and correlated with sociodemographic variables. The rate of ZIKV infection was 10.8%. ZIKV transmission by mosquitoes was the best-known means of virus acquisition, while transmission of ZIKV by sexual intercourse as well as mother-fetus transmission was known by less than half of the women. The use of insect repellent, reported by 53% of participants, was correlated with higher education and personal directives from health professionals. Condom use was reported by 19.5% of subjects. Improved strategies to increase awareness of ZIKV infection and its consequences, designed to appeal to specific, targeted populations, are clearly necessary to more accurately prevent the spread of this infection and diminish adverse consequences in the pregnant population.

Robust epidemiological and biological evidence supports a causal link between prenatal Zika Virus (ZIKV) infection and congenital brain abnormalities including microcephaly. However, it remains uncertain if ZIKV infection in pregnancy also increases the risk for other adverse fetal and birth outcomes. In a prospective cohort study we investigated the influence of ZIKV on the prevalence of prematurity, low birth weight, small-for-gestational-age, and fetal death as well as microcephaly (i.e., overall and disproportionate) in the offspring of women attending a high-risk pregnancy clinic during the recent ZIKV outbreak in Brazil. During the recruitment period (01 March 2016-23 August 2017), urine samples were tested for ZIKV by RT-PCR from all women attending the high-risk pregnancy clinic at Jundiaí University Hospital and from the neonates after delivery. Of the 574 women evaluated, 44 (7.7%) were ZIKV RT-PCR positive during pregnancy. Of the 409 neonates tested, 19 (4.6%) were ZIKV RT-PCR positive in the first 10 days of life. In this cohort, maternal ZIKV exposure was not associated with increased risks of prematurity, low birth weight, small-for-gestational-age, or fetal death. However, relative to ZIKV-negative neonates, ZIKV-positive infants had a five-fold increased risk of microcephaly overall (RR 5.1, 95% CI 1.2-22.5) and a ten-fold increased risk of disproportionate microcephaly (RR 10.3, 95% CI 2.0-52.6). Our findings provide new evidence that, in a high-risk pregnancy cohort, ZIKV RT-PCR positivity in the neonate at birth is strongly associated with microcephaly. However, ZIKV infection during pregnancy does not appear to influence the risks of prematurity, low birth weight, small-for-gestational-age or fetal death in women who already have gestational comorbidities. The results suggest disproportion between neonatal head circumference and weight may be a useful screening indicator for the detection of congenital microcephaly associated with ZIKV infection.

Zika virus (ZIKV) is highly neurotropic after crossing the placenta, inducing teratogenic effects that result in delayed development and microcephaly in infants. The available evidence for vertical transmission of this infection is based on placental studies showing alterations in trophoblastic tissue. However, complete characterization of ZIKV-infected placenta and involved pathways has yet to be fully clarified. This case report of placental ZIKV infection describes morphologic and molecular changes in the placenta. Hyperplasia of placental Hofbauer cells in chorionic villi and numerous histiocyte-like cells in the decidua were observed. The decidua, fibroblasts, and chorion, as well as circulating cells in the intravascular compartment stained positive for ZIKV envelop protein. Deciduitis was present on the maternal surface of the placenta, with a prevalence of lymphocytes associated with vasculitis. A high level of uncommitted CD3 T lymphocytes were present, in addition to CD4 and CD8 cells. Elevated expression of the apoptosis inhibitor, Bcl-2, was observed in syncytiotrophoblasts. These parameters may promote the persistence of ZIKV in placental tissue and transmission to the fetus.

Purpose: To follow the visual acuity development of children exposed to or infected with the Zika virus (ZIKV) during gestation and to relate potential visual acuity deficits to their clinical condition., Methods: In this prospective study, visual acuity was measured via Teller Acuity Cards in three groups of children: (1) those with confirmed ZIKV exposure (ZE) through the mother only, (2) those with confirmed infection (ZI), and (3) unaffected controls. Visual acuity was measured 2-4 times in each child during the first 30 months of age., Results: The study included 22 children in the ZE group, 11 in the ZI group, and 27 controls. Visual acuity developed normally in both patient groups, including infected patients (ZI) that did not manifest clinical symptoms. In a small subgroup of patients with characteristics consistent with congenital Zika syndrome (CZS), visual acuity was within normative values, with the exception of single child with chorioretinal atrophy., Conclusions: In this southeastern Brazil study cohort, visual acuity development seemed to progress normally in infected children without CZS symptoms., (Copyright © 2020 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Paired maternal and newborn urine and amniotic fluid from 138 subjects collected during a Zika virus (ZIKV) outbreak was analyzed for ZIKV by gene amplification (RT-qPCR), and the findings were correlated with clinical symptoms and neurological anomalies in the babies. ZIKV was detected in 1 of 9 symptomatic women (11.1%) and in 19 of 129 asymptomatic women (14.7%). Neurological manifestations were present in 19 babies (13.7%), 10 of 20 (50%) positive and 9 of 119 (7.6%) negative (p < 0.001) for ZIKV. Twelve (8.6%) urines collected during gestation were ZIKV-positive; only 2 remained positive for ZIKV postpartum. Six (4.1%) newborn urines collected within 1 day of delivery were ZIKV-positive cases. In 3 of these cases, ZIKV was detected in mother's urine pre- and postpartum and in both mother's urine and babies' urine. Four of the amniotic fluid samples (2.9%) were ZIKV-positive. Among ZIKV-negative babies with neurological sequel, 87.5% were female; in contrast, 72.7% ZIKV-positive babies with neurological abnormalities were male (p = 0.019). We conclude that during a ZIKV outbreak, clinical symptoms and ZIKV detection in biological fluids are poor predictors of infection and adverse neurologic sequel in newborns.

Purpose: The Jundiaí Zika Cohort (JZC) is a prospective pregnancy and birth cohort setup in the State of São Paulo, Brazil, to investigate the epidemic of cases of microcephaly and other neurological disorders, presumed to be associated with Zika virus (ZIKV) infection., Participants: A total of 748 women with high-risk pregnancies were recruited in the period of March 2016 to August 2017., Findings to Date: Baseline sociodemographic and medical data were collected at recruitment from 737 pregnant women. Biological samples (ie, blood, saliva and urine) were collected from 695 of the pregnant women (94.3%), of whom 53 (7.6%) were ZIKV-positive on subsequent testing by reverse transcription polymerase chain reaction (RT-PCR) in urine. Biological sample (ie, blood, saliva, urine and cerebrospinal fluid) were collected within 10 days of birth from 409 (57.4%) of the liveborn infants, of whom 19 (4.6%) were ZIKV-positive on subsequent testing by RT-PCR in urine. All remaining biological specimens, as well as colostrum, umbilical cord and placental samples, have been stored in a secure biorepository. Antenatal and postnatal imaging studies and neonatal anthropometry were carried out., Future Plans: The JZC provides a unique data set which will continue to be explored to study the effects of pregnancy comorbidities on Zika virus infection during pregnancy, the long-term outcomes of children with congenital Zika infection and how physiotherapy and group interventions can improve outcomes for congenitally-infected children. All women in the cohort have reached the end of their pregnancy and currently the oldest children are 2 years old. The study will continue until all the children reach their third birthday (April 2021)., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Through a systematic review, this essay aimed at revising the concepts of severe pertussis, updating the epidemiology, pathophysiology, clinical presentation, antibiotic therapy and auxiliary therapeutic options for symptomatology and complications., Data Sources: This review considered publications from the last 30years in the databases US National Library of Medicine (PubMed), Scientific Electronic Library Online (SciELO), Literatura Latino-americana e do Caribe em Ciências da Saúde (LILACS), Cochrane, Google Scholar, as well as protocols of the Ministry of Health and recommendations of the Centers for Disease Control and Prevention, related to childhood pertussis (whooping cough), with emphasis on its severe form. This research was based on keywords derived from the terms "pertussis", "azithromycin", "antitussives", "leukocyte reduction" in Portuguese and English. Duplicate studies and those with unavailable full-text were excluded., Data Synthesis: Among 556 records found, 54 were selected for analysis. Pertussis, as a reemerging disease, has affected all age groups, evidencing the transient immunity conferred by infection and vaccination. Severe cases occur in neonates and infants, with secondary viral and bacterial complications and malignant pertussis, a longside hyperleukocytosis, respiratory failure and shock. Macrolides continue to be the chosen antibiotics, while antitussives for coughing remain without efficacy. The prompt treatment in Intensive Care Units improved the prognostic in severe cases, and transfusion was promising among procedures for leukoreduction., Conclusions: Approaching severe pertussis in childhood remains a challenge for diagnostic and therapy, as the available therapeutic options are still unsatisfactory. Strategies of prevention are expected to reduce the occurrence of severe cases, while new studies should confirm the role of auxiliary therapies.

Introduction: Zika virus (ZIKV) infection during pregnancy is a known cause of microcephaly and other congenital and developmental anomalies. In the absence of a ZIKV vaccine or prophylactics, principal investigators (PIs) and international leaders in ZIKV research have formed the ZIKV Individual Participant Data (IPD) Consortium to identify, collect and synthesise IPD from longitudinal studies of pregnant women that measure ZIKV infection during pregnancy and fetal, infant or child outcomes., Methods and Analysis: We will identify eligible studies through the ZIKV IPD Consortium membership and a systematic review and invite study PIs to participate in the IPD meta-analysis (IPD-MA). We will use the combined dataset to estimate the relative and absolute risk of congenital Zika syndrome (CZS), including microcephaly and late symptomatic congenital infections; identify and explore sources of heterogeneity in those estimates and develop and validate a risk prediction model to identify the pregnancies at the highest risk of CZS or adverse developmental outcomes. The variable accuracy of diagnostic assays and differences in exposure and outcome definitions means that included studies will have a higher level of systematic variability, a component of measurement error, than an IPD-MA of studies of an established pathogen. We will use expert testimony, existing internal and external diagnostic accuracy validation studies and laboratory external quality assessments to inform the distribution of measurement error in our models. We will apply both Bayesian and frequentist methods to directly account for these and other sources of uncertainty., Ethics and Dissemination: The IPD-MA was deemed exempt from ethical review. We will convene a group of patient advocates to evaluate the ethical implications and utility of the risk stratification tool. Findings from these analyses will be shared via national and international conferences and through publication in open access, peer-reviewed journals., Trial Registration Number: PROSPERO International prospective register of systematic reviews (CRD42017068915)., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. Published by BMJ.)

BACKGROUND The Zika virus is an arbovirus that has as main source of transmission the bite of infected insects of the genus Aedes and has been associated with cases of congenital malformation and microcephaly in neonates. However, other sources of transmission have been identified since the emergence of this virus in the world population, such as vertical transmission by semen and possibly other body fluids such as vaginal secretion and breast milk. CASE REPORT An infant, born to a mother whose previous delivery was a baby with severe microcephaly, was normal and was negative for Zika virus at birth but developed secondary microcephaly 1 month later, that persisted. The baby was exclusively breast-fed and Zika virus was present in the mother's milk. CONCLUSIONS We report the detection of Zika virus exclusively in the breast milk of a woman after her second delivery of an infant, who later developed microcephaly. This case is consistent with possible vertical transmission.

The original PDF version of this Article contained errors in the spelling of Luiz Carlos Caires-Júnior, Uirá Souto Melo, Bruno Henrique Silva Araujo, Alessandra Soares-Schanoski, Murilo Sena Amaral, Kayque Alves Telles-Silva, Vanessa van der Linden, Helio van der Linden, João Ricardo Mendes de Oliveira, Nivia Maria Rodrigues Arrais, Joanna Goes Castro Meira, Ana Jovina Barreto Bispo, Esper Abrão Cavalheiro, and Robert Andreata-Santos, which were incorrectly given as Luiz Carlos de Caires Jr., UiráSouto Melo, Bruno Silva Henrique Araujo, Alessandra Soares Schanoski, MuriloSena Amaral, Kayque Telles Alves Silva, Vanessa Van der Linden, Helio Van der Linden, João Mendes Ricardo de Oliveira, Nivia Rodrigues Maria Arrais, Joanna Castro Goes Meira, Ana JovinaBarreto Bispo, EsperAbrão Cavalheiro, and Robert Andreata Santos. Furthermore, in both the PDF and HTML versions of the Article, the top panel of Fig. 3e was incorrectly labeled '10608-1' and should have been '10608-4', and financial support from CAPES and DECIT-MS was inadvertently omitted from the Acknowledgements section. These errors have now been corrected in both the PDF and HTML versions of the Article.

Congenital Zika syndrome (CZS) causes early brain development impairment by affecting neural progenitor cells (NPCs). Here, we analyze NPCs from three pairs of dizygotic twins discordant for CZS. We compare by RNA-Seq the NPCs derived from CZS-affected and CZS-unaffected twins. Prior to Zika virus (ZIKV) infection the NPCs from CZS babies show a significantly different gene expression signature of mTOR and Wnt pathway regulators, key to a neurodevelopmental program. Following ZIKV in vitro infection, cells from affected individuals have significantly higher ZIKV replication and reduced cell growth. Whole-exome analysis in 18 affected CZS babies as compared to 5 unaffected twins and 609 controls excludes a monogenic model to explain resistance or increased susceptibility to CZS development. Overall, our results indicate that CZS is not a stochastic event and depends on NPC intrinsic susceptibility, possibly related to oligogenic and/or epigenetic mechanisms.

Objective: To assess the level of caregiver knowledge about respiratory signs and symptoms of acute respiratory infection (ARI) as well as their ability to detect the early warning signs and need for medical assistance in children referred to an emergency service., Methods: This is a prospective, cross-sectional study. A standardized questionnaire with questions on the perception of the severity of ARI signs and symptoms was applied to caregivers of pediatric patients assisted in the emergency room of a university hospital from August 2011 to May 2012. Chi-square and Student's t-tests were used to determine which variables contributed with caregivers' recognition of severity of acute respiratory diseases., Results: 499 caregivers were interviewed. The most cited causes of ARI were flu syndrome (78.6%), common cold (73.9%), pharyngitis (64.1%), and pneumonia (54.5%). Fever (34.1%) and cough (15.8%) were major reasons for referral to hospital. The most cited signs of severity recognized by caregivers were fever (99.6%), dyspnea (91.4%), wheezing (86.4%), adynamia (80.2%), coughing (79.8%), and tachypnea (78.6%). Children's history of respiratory diseases (p=0.002), caregiver's age (p=0.010) and marital status (p=0.014) were significantly associated with tachypnea, the most severe ARI symptom., Conclusions: Although caregivers of children can recognize ARI most important signs and symptoms, they are unable to judge severity, which may delay medical care and early treatment.

Background: Chikungunya virus (CHIKV) is a re-emerging arbovirus that is causing outbreaks in several countries of the Americas. The virus was introduced in Brazil in 2014, and since then, several Brazilian states have notified autochthonous cases., Objectives: Provide additional evidence on a CHIKV outbreak and an outline of the laboratory and clinical profile of symptomatic patients in Sergipe, Brazil., Study Design: In February 2016, we collected 142 serum samples from symptomatic patients for arboviruses in Sergipe, Brazil. All samples were submitted to qRT-PCR for the emerging arboviruses circulating in Brazil - ZIKV, CHIKV, and DENV - and later submitted to the immunoenzymatic assay. RNA positive samples were randomly selected and sequenced for characterization of the genotype involved in the outbreak., Results: Our study had 75.35% (107/142) positivity for CHIKV infection, with all age groups and genera being equally infected. The virus was identified in 11 of the 13 cities studied in that state, including the ECSA genotype. Importantly, fever was the only statistically significant symptoms for CHIKV infection (p<0.05), while asthenia was significantly associated with symptomatic patients that were CHIKV-negative (p<0.05)., Conclusions: Our findings support the importance of fever as a clinical marker and contribute to molecular and serological surveillance data, which may help in the understanding of CHIKV circulation, emergence and clinical description., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Introduction The relevance of allergic rhinitis is unquestionable. This condition affects people's quality of life and its incidence has increased over the last years. Objective Thus, this study aims to analyze the effectiveness of subcutaneous injectable immunotherapy in cases of nasal itching, sneeze, rhinorrhea and nasal congestion in allergic rhinitis patients. Methods In the present study, the same researcher analyzed the records of 281 patients. Furthermore, the researchers identified allergens through puncture cutaneous tests using standardized extracts containing acari, fungi, pet hair, flower pollen, and feathers. Then, the patients underwent treatment with subcutaneous specific immunotherapy, using four vaccine vials for desensitization, associated with environmental hygiene. The authors analyzed conditions of nasal itching, sneeze, rhinorrhea, and nasal congestion throughout the treatment, and assigned them with a score ranging from zero (0), meaning absence of these symptoms to three (3), for severe cases. The symptoms were statistically compared in the beginning, during, and after treatment. Results In this study, authors analyzed the cases distribution according to age and the evolution of symptomatology according to the scores, comparing all phases of treatment. The average score for the entire population studied was 2.08 before treatment and 0.44 at the end. These results represent an overall improvement of ∼79% in symptomatology of allergic rhinitis in the studied population. Conclusion The subcutaneous immunotherapy as treatment of allergic rhinitis led to a reduction in all symptoms studied, improving the quality of life of patients, proving itself as an important therapeutic tool for these pathological conditions.

Background: Human parainfluenza viruses account for a significant proportion of lower respiratory tract infections in children., Objective: To assess the prevalence of Human parainfluenza viruses as a cause of acute respiratory infection and to compare clinical data for this infection against those of the human respiratory syncytial virus., Methods: A prospective study in children younger than five years with acute respiratory infection was conducted. Detection of respiratory viruses in nasopharyngeal aspirate samples was performed using the indirect immunofluorescence reaction. Length of hospital stay, age, clinical history and physical exam, clinical diagnoses, and evolution (admission to Intensive Care Unit or general ward, discharge or death) were assessed. Past personal (premature birth and cardiopathy) as well as family (smoking and atopy) medical factors were also assessed., Results: A total of 585 patients were included with a median age of 7.9 months and median hospital stay of six days. No difference between the HRSV+ and HPIV+ groups was found in terms of age, gender or length of hospital stay. The HRSV+ group had more fever and cough. Need for admission to the Intensive Care Unit was similar for both groups but more deaths were recorded in the HPIV+ group. The occurrence of parainfluenza peaked during the autumn in the first two years of the study., Conclusion: Parainfluenza was responsible for significant morbidity, proving to be the second-most prevalent viral agent in this population after respiratory syncytial virus. No difference in clinical presentation was found between the two groups, but mortality was higher in the HPIV+ group., (Copyright © 2015. Published by Elsevier Editora Ltda.)

Objective: to estimate the prevalence of infection by respiratory viruses in pediatric patients with cancer and acute respiratory infection (ARI) and/or fever., Methods: cross-sectional study, from January 2011 to December 2012. The secretions of nasopharyngeal aspirates were analyzed in children younger than 21 years with acute respiratory infections. Patients were treated at the Grupo em Defesa da Criança Com Câncer (Grendacc) and University Hospital (HU), Jundiaí, SP. The rapid test was used for detection of influenza virus (Kit Biotrin, Inc. Ireland), and real-time multiplex polymerase chain reaction (FTD, Respiratory pathogens, multiplex Fast Trade Kit, Malta) for detection of influenza virus (H1N1, B), rhinovirus, parainfluenza virus, adenovirus, respiratory syncytial virus, human parechovirus, bocavirus, metapneumovirus, and human coronavirus. The prevalence of viral infection was estimated and association tests were used (χ(2) or Fisher's exact test)., Results: 104 samples of nasopharyngeal aspirate and blood were analyzed. The median age was 12 ± 5.2 years, 51% males, 68% whites, 32% had repeated ARIs, 32% prior antibiotic use, 19.8% cough, and 8% contact with ARIs. A total of 94.3% were in good general status. Acute lymphocytic leukemia (42.3%) was the most prevalent neoplasia. Respiratory viruses were detected in 50 samples: rhinoviruses (23.1%), respiratory syncytial virus AB (8.7%), and coronavirus (6.8%). Co-detection occurred in 19% of cases with 2 viruses and in 3% of those with 3 viruses, and was more frequent between rhinovirus and coronavirus 43. Fever in neutropenic patients was observed in 13%, of which four (30.7) were positive for viruses. There were no deaths., Conclusions: the prevalence of respiratory viruses was relevant in the infectious episode, with no increase in morbidity and mortality. Viral co-detection was frequent in patients with cancer and ARIs., (Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.)

Unlabelled: To review if pollution and climate changes can influence respiratory tract infections in children., Data Source: Articles published on the subject in PubMed, SciELO, Bireme, EBSCO and UpTodate were reviewed. The following inclusion criteria were considered: scientific papers between 2002 and 2012, study design, the pediatric population, reference documents such as the CETESB and World Health Organization Summary of the data: We analyzed research that correlated respiratory viruses and climate and/or pollution changes. Respiratory syncytial virus has been the virus related most to changes in climate and humidity. Other "old and new" respiratory viruses such as Human Bocavirus, Metapneumovirus, Parechovirus and Parainfuenza would need to be investigated owing to their clinical importance. Although much has been studied with regard to the relationship between climate change and public health, specific studies about its influence on children's health remain scarce.

Introduction The presence of respiratory viruses in lymphoid tissues of the nasopharynx and oropharynx and its impact on recurrent infections and hypertrophy of these tissues are not yet fully understood. Objective To identify and determine the prevalence of major respiratory viruses in nasopharyngeal secretions and adenoid tissue pre- and postoperatively of children undergoing adenoidectomy. Methods A prospective observational study was conducted in 36 patients under 12 years of age with upper airway lymphoid hypertrophy who were undergoing adenoidectomy, in which various respiratory viruses were investigated using real-time polymerase chain reaction in adenoid tissue and nasopharyngeal secretions collected preoperatively and 30 days postoperatively. Results At least 1 viral agent was isolated in any of the samples collected in 58.3% of children and 25.9% of total samples. Respiratory viruses were identified in 33.8% of preoperative nasopharyngeal specimens and in 19.8% of postoperative secretion. Of the 21 patients with positive results for any respiratory virus, 6 (28.6%) had more than 1 virus. Considering all 36 respiratory viruses found, the main agent isolated was rhinovirus (27.8%), followed by bocavirus (22.2%). Conclusion The virus found more frequently in all samples was rhinovirus. After removal of adenoid tissue, there was a decrease in the prevalence of the virus contained in nasopharyngeal secretion 30 days after surgery.

Objective: To study the antibody prevalence against dengue in the municipality of Jundiaí, São Paulo, Brazil, due to the low number of official confirmed autochthonous cases., Methods: A serological study on dengue infection was conducted during January 2010 and previous reports on dengue and entomological surveillance during that period were reviewed., Results: A prevalence of 7.8% IgG positive (68:876) was found. Furthermore, based on the detection of IgM antibodies in five samples, it was observed that the incidence of dengue in the city at the time of the survey contrasts with the absence of notifications by local health authorities over the same period of time., Conclusion: These results highlight the discrepancies between the actual and the detected number of dengue infections, possibly due to significant numbers of asymptomatic infections aggravated by difficulties with dengue clinical diagnosis.

Background: To determine the prevalence, age distribution, seasonality and clinical characteristics of Lyme-simile disease in Brazilians less than 15 years of age. METHODS. From July, 1998 to November, 2000, a cross-sectional study was conducted in 333 patients with skin rash and fever. Paired blood samples were collected for identification of the pathogens. Only 193 samples which were negative for other pathogens (Parvovirus B19 Human, Herpesvirus 6 Human, Measles, Rubella, Dengue, Scarlet fever and Enterovirus), were tested for borreliosis by Enzyme-Linked Immunosorbent Assay and Western-blotting. Other clinical, socioeconomic, demographic and climatic variables were studied., Results: Prevalence of the disease was 6.2%(12/193). Of the variables studied, there was predominance in: <6 years old (83.2%); females (66.7%); being from the city of Franco da Rocha (58.3 %); and a summer/fall seasonality. The duration of care was 4 days. Signs and symptoms with statistical significance were itching; absence of lip notch and ocular pain; irritability and good clinical condition. Other clinical data presented were: pruritus (90%), irritability (80%) and fever (38 masculineC) (58.3%) with a duration of 1 to 3 days. Erythema was maculo-papular (40%), urticaria-like (25%) and scarlatiniform (16.7%), occurring predominately on the trunk (60%). There were no primary clinical evidences of Lyme-simile disease in the patients under study. The sensitivity and specificity of the clinical diagnosis as opposed to the laboratory diagnosis was zero. There was no initial clinical suspicion of the disease in the 10 cases studied and followed up for two years that showed no evidence of cardiologic or neurological complications. This is the first study of Lyme-simile in Brazilian children., Conclusion: Prevalence of Lyme-simile disease was low, and it was not remembered at the initial diagnosis of those with skin rash. However, practical knowledge is necessary, demanding increased medical attention.

The purpose of this study was to identify the rate of infections due to RSV and other viruses in children. In addition we have analyzed demographic data and clinical characteristics of the RSV-positive patients comparing with patients infected by other respiratory viruses. We also described the seasonality of the RSV occurrence in a hospital in São Paulo. Children below 5 years old admitted in Santa Casa de São Paulo Hospital between February 2005 and September 2006 due to acute respiratory infections (ARI) were included. A nasopharyngeal specimens were obtained with sterile No. 5 French feeding catheters as soon as possible (usually within 24 h). Specimens were kept refrigerated at 4 degrees C and transported to Adolfo Lutz Institute, where the indirect immunofluorescent assay was performed. Virus identified by these assay included RSV, Adenovirus, Influenza A and B virus and Parainfluenza 1, 2, and 3. Clinical data from each group was compared. Four hundred and fifty five cases were included in the study, with 30% positive for some type of virus. Viruses that were identified included Respiratory Syncytial Virus (73.03%), Influenza (8.42%), Parainfluenza (8.42%) and Adenovirus (3.37%). We divided the subjects in 3 groups: Group 1 RSV-Positive, Group 2 Other Positive Viruses and Group 3 Negative for Respiratory Virus. Mean age (months) was of 7.5 for RSV-positive children, 7.6 for other viruses, and 8 for negative for respiratory virus. The RSV-Positive Group was significantly younger than the Group Negative for Respiratory Virus (p<0.05). Signs of UAI were more present in the Positive RSV Group (p<0.05). General mortality was of 2.41%. There was a higher incidence of RSV between the months of March and August in the two years of the study. Our study indicates RSV as the most prevalent viral agent in children admitted due to (ARI), especially in infants below 3 months old. We have also found that infections due to RSV can occur in months others than the classic seasonal period.

Objective: To analyze the prevalence of IgG antibodies to human parvovirus B19., Methods: Cross-sectional study in a suburban community in São Paulo, Southeastern Brazil, between November 1990 and January 1991. Randomly selected (N=435) representative samples of sera were collected from healthy children older than 15 days old and adults up to 40 years old. IgG antibodies were detected using ELISA., Results: High prevalence of IgG antibodies to B19 parvovirus was found in 87% of newborns. The prevalence of maternally derived IgG antibodies exponentially plunged up to the 19th month of age. Low prevalence of antibodies was found in the first 4 years of life, increasing up to 72% in those aged 31-40 years. It was estimated that the average age of first infection in this population is 21 +/- 7 years old and the optimal age for vaccination with a hypothetical vaccine would be 1 year of age., Conclusions: Parvovirus B19 IgG antibody prevalence was high in newborns and those aged 31-40 years. The analysis by age groups showed a pattern similar to that found in previous studies, i.e., low prevalence of infection in children that increases with age.

Purpose: To compare two kinds of polymer-coated tantalum stents with bare tantalum stents (control) to determine if the coatings can improve thromboresistance., Methods: Twenty-seven Fontaine-Dake stents were balloon expanded in three 8-mm x 80-cm polytetrafluoroethylene (PTFE) grafts; 9 stents were bare tantalum (T); 9 were coated with polyetherurethane (PL); and 9 were coated with parylene (PA). There were 9 stents placed in each graft as follows: 3 tantalum, 3 polyetherurethane, and 3 parylene. In swine whose platelets had been radiolabeled with indium 111, the ends of each stented graft were connected to 14F femoral and venous sheaths to create an ex vivo fistula. Each graft was exposed to blood for 30, 60, and 120 minutes. At the end of each test period, the stented grafts were disconnected from the sheaths, flushed with saline until clear, and then flushed with formalin. The stents were removed from the grafts, and a radionuclide well counter recorded radionuclide counts from each stent type at each period of blood contact. These values were converted to platelet density per 1000 microns 2. Stents were then photographed and scanned with electron microscopy (EM) for qualitative analysis. Possible significant differences in platelet adhesion with the three types of stents (both between stent groups and within stent groups) were examined using a two-tailed Student's t-test., Results: There were significantly fewer platelets adsorbed on PA versus T at all time periods (p < 0.005); on PL versus T at 60 and 120 minutes (p < 0.005); and on PA versus PL at 30 and 120 minutes (p < 0.0005). There was no significant difference in platelet density within each stent group (p = 0.1). Mean platelet density (number of platelets per 1000 microns 2 +/- SD) was as follows: at 30 minutes: T = 1891 +/- 965; PL = 373 +/- 193; and PA = 27 +/- 3; at 60 minutes: T = 6226 +/- 1621; PL = 1573 +/- 793; and PA = 1185 +/- 710; at 120 minutes: T = 5307 +/- 591; PL = 3164 +/- 318; and PA = 180 +/- 100. Gross inspection of the 120-minute groups demonstrated focal areas of thrombus on T, less on PL, and none on PA. Scanning EM demonstrated extensive platelet accumulation covering T at all time periods, less on PL, and even less on PA.

The sensitivity and specificity of salivary rubella antibody detection was investigated using samples collected from 301 children after a mass vaccination campaign in the state of São Paulo, Brazil. Saliva samples were collected by 2 different methods: directly dribbling into a container or using a commercial collecting device. Corresponding finger-prick blood samples were collected on filter paper. Rubella specific immunoglobulin G (IgG) was measured in saliva by antibody capture radioimmunoassay and in blood samples by indirect enzyme-linked immunosorbent assay. The detection of salivary rubella specific IgG showed good correlation with the detection of rubella antibody in the blood samples. For both collecting techniques the predictive value for a positive saliva test was > 99% compared with the results from the blood tests. However, the predictive value for a negative saliva test was only 58.3% for a dribbled sample, compared to 100% for saliva collected using the commercial device. Moreover, collecting saliva by dribbling from children less than 4 years old was difficult. The detection of rubella specific IgG in saliva collected using a commercial device proved to be sensitive and specific in this epidemiological study, encouraging its more widespread application as a means of surveillance after mass vaccination.

A rubella serological survey of 476 individuals selected by cluster sampling technique from Caieiras, a small town located in the outskirts of São Paulo city, southeastern Brazil, was carried out over the period November 1990-January 1991. The aim of the study was to characterize rubella epidemiology in a representative non-immunized community in south east Brazil. The survey comprised a seroprevalence study, stratified by age (0-40 years) and a seroconversion study of rubella vaccine in non-infected children below 2 years of age. Mathematical techniques were applied to resultant data sets to determine the age dependent rates of decay in the proportion of individuals with maternally derived antibodies, vaccine seroconversion, and infection of susceptibles, termed the force of infection, and to estimate the average age at first infection.