Suchergebnisse

Congenital rubella syndrome (CRS) continues to cause disability among unvaccinated populations in countries with no or insufficient rubella vaccine coverage to prevent transmission. We systematically reviewed the literature on birth outcomes associated with CRS to estimate the duration, severity, and frequency of combinations of morbidities. We searched PubMed, the Science Citation Index, and references from relevant articles for studies in English with primary data on the frequency of CRS manifestations for ≥20 cases and identified 65 studies representing 66 study populations that met our inclusion criteria. We abstracted available data on CRS cases with one or more hearing, heart, and/or eye defect following maternal rubella infection during the period of 0–20 weeks since the last menstrual period. We assessed the quality and weight of the available evidence using a modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Most of the evidence originates from studies in developed countries of cohorts of infants identified with CRS in the 1960s and 1970s, prior to the development of standardized definitions for CRS and widespread use of vaccine. We developed estimates of undiscounted disability‐adjusted life years (DALYs) lost per CRS case for countries of different income levels. The estimates ranged from approximately 19 to 39 for high‐income countries assuming optimal treatment and from approximately 29 to 39 DALYs lost per CRS case in low‐ and lower‐ middle‐income countries assuming minimal treatment, with the lower bound based on 2010 general global burden of disease disability weights and the upper bound based on 1990 age‐specific and treatment‐specific global burden of disease disability weights. Policymakers and analysts should appreciate the significant burden of disability caused by CRS as they evaluate opportunities to manage rubella.

Although most infections with the rubella virus result in relatively minor sequelae, rubella infection in early pregnancy may lead to severe adverse outcomes for the fetus. First recognized in 1941, congenital rubella syndrome (CRS) can manifest with a diverse range of symptoms, including congenital cataracts, glaucoma, and cardiac defects, as well as hearing and intellectual disability. The gestational age of the fetus at the time of the maternal rubella infection impacts the probability and severity of outcomes, with infection in early pregnancy increasing the risks of spontaneous termination (miscarriage), fetal death (stillbirth), birth defects, and reduced survival for live‐born infants. Rubella vaccination continues to change the epidemiology of rubella and CRS globally, but no models currently exist to evaluate the economic benefits of rubella management. This systematic review provides an overall assessment of the weight of the evidence for the outcomes associated with rubella infections in the first 20 weeks of pregnancy. We identified, evaluated, and graded 31 studies (all from developed countries) that reported on the pregnancy outcomes of at least 30 maternal rubella infections. We used the available evidence to estimate the increased risks of spontaneous termination, fetal death, infant death, and CRS as a function of the timing of rubella infection in pregnancy and decisions about induced termination. These data support the characterization of the disability‐adjusted life years for outcomes associated with rubella infection in pregnancy. We find significant impacts associated with maternal rubella infections in early pregnancy, which economic analyses will miss if they only focus on live births of CRS cases. Our estimates of fetal loss from increased induced terminations due to maternal rubella infections provide context that may help to explain the relatively low numbers of observed CRS cases per year despite potentially large burdens of disease. Our comprehensive review of the weight of the evidence of all pregnancy outcomes demonstrates the importance of including all outcomes in models that characterize rubella‐related disease burdens and costs.

Population immunity depends on the dynamic levels of immunization coverage that countries achieve over time and any transmission of viruses that occur within the population that induce immunity. In the context of developing a dynamic transmission model for measles and rubella to support analyses of future immunization policy options, we assessed the model inputs required to reproduce past behavior and to provide some confidence about model performance at the national level. We reviewed the data available from the World Health Organization (WHO) and existing measles and rubella literature for evidence of historical reported routine and supplemental immunization activities and reported cases and outbreaks. We constructed model input profiles for 180 WHO member states and three other areas to support disease transmission model development and calibration. The profiles demonstrate the significant variability in immunization strategies used historically by regions and member states and the epidemiological implications of these historical choices. The profiles provide a historical perspective on measles and rubella immunization globally at the national level, and they may help immunization program managers identify existing immunity and/or knowledge gaps.

BACKGROUND: Rubella-containing vaccines (RCV) are not yet part of the Democratic Republic of the Congo's (DRC) vaccination program; however RCV introduction is planned before 2020. Because documentation of DRC's historical burden of rubella virus infection and congenital rubella syndrome (CRS) has been minimal, estimates of the burden of rubella virus infection and of CRS would help inform the country's strategy for RCV introduction. METHODS: A rubella antibody seroprevalence assessment was conducted using serum collected during 2008-2009 from 1605 pregnant women aged 15-46years attending 7 antenatal care sites in 3 of DRC's provinces. Estimates of age- and site-specific rubella antibody seroprevalence, population, and fertility rates were used in catalytic models to estimate the incidence of CRS per 100,000 live births and the number of CRS cases born in 2013 in DRC. RESULTS: Overall 84% (95% CI 82, 86) of the women tested were estimated to be rubella antibody seropositive. The association between age and estimated antibody seroprevalence, adjusting for study site, was not significant (p=0.10). Differences in overall estimated seroprevalence by study site were observed indicating variation by geographical area (p⩽0.03 for all). Estimated seroprevalence was similar for women declaring residence in urban (84%) versus rural (83%) settings (p=0.67). In 2013 for DRC nationally, the estimated incidence of CRS was 69/100,000 live births (95% CI 0, 186), corresponding to 2886 infants (95% CI 342, 6395) born with CRS. CONCLUSIONS: In the 3 provinces, rubella virus transmission is endemic, and most viral exposure and seroconversion occurs before age 15years. However, approximately 10-20% of the women were susceptible to rubella virus infection and thus at risk for having an infant with CRS. This analysis can guide plans for introduction of RCV in DRC. Per World Health Organization recommendations, introduction of RCV should be accompanied by a campaign targeting all children 9months to 14years of age as well as vaccination of women of child bearing age through routine services.