RESUMO
BACKGROUND: Colombia experienced a Zika virus (ZIKV) outbreak in 2015-2016. To assist with planning for medical and supportive services for infants affected by prenatal ZIKV infection, we used a model to estimate the number of pregnant women infected with ZIKV and the number of infants with congenital microcephaly from August 2015 to August 2017. METHODS: We used nationally reported cases of symptomatic ZIKV disease among pregnant women and information from the literature on the percent of asymptomatic infections to estimate the number of pregnant women with ZIKV infection occurring August 2015-December 2016. We then estimated the number of infants with congenital microcephaly expected to occur August 2015-August 2017. To compare to the observed counts of infants with congenital microcephaly due to all causes reported through the national birth defects surveillance system, the model was time limited to produce estimates for February-November 2016. FINDINGS: We estimated 1140-2160 (interquartile range [IQR]) infants with congenital microcephaly in Colombia, during August 2015-August 2017, whereas 340-540 infants with congenital microcephaly would be expected in the absence of ZIKV. Based on the time limited version of the model, for February-November 2016, we estimated 650-1410 infants with congenital microcephaly in Colombia. The 95% uncertainty interval for the latter estimate encompasses the 476 infants with congenital microcephaly reported during that approximate time frame based on national birth defects surveillance. INTERPRETATION: Based on modeled estimates, ZIKV infection during pregnancy in Colombia could lead to 3-4 times as many infants with congenital microcephaly in 2015-2017 as would have been expected in the absence of the ZIKV outbreak. FUNDING: This publication was made possible through support provided by the Bureau for Global Health, U.S. Agency for International Development under the terms of an Interagency Agreement with Centers for Disease Control and Prevention.
Assuntos
Microcefalia/epidemiologia , Microcefalia/virologia , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/virologia , Infecção por Zika virus/congênito , Infecção por Zika virus/epidemiologia , Colômbia/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Feminino , Humanos , Lactente , Modelos Estatísticos , Mães , Gravidez , Zika virus/isolamento & purificação , Infecção por Zika virus/transmissãoRESUMO
IMPORTANCE: Zika virus (ZIKV) infection during pregnancy is a cause of congenital microcephaly and severe fetal brain defects, and it has been associated with other adverse pregnancy and birth outcomes. OBJECTIVE: To estimate the number of pregnant women infected with ZIKV in Puerto Rico and the number of associated congenital microcephaly cases. DESIGN, SETTING, AND PARTICIPANTS: We conducted a modeling study from April to July 2016. Using parameters derived from published reports, outcomes were modeled probabilistically using Monte Carlo simulation. We used uncertainty distributions to reflect the limited information available for parameter values. Given the high level of uncertainty in model parameters, interquartile ranges (IQRs) are presented as primary results. Outcomes were modeled for pregnant women in Puerto Rico, which currently has more confirmed ZIKV cases than any other US location. EXPOSURE: Zika virus infection in pregnant women. MAIN OUTCOMES AND MEASURES: Number of pregnant women infected with ZIKV and number of congenital microcephaly cases. RESULTS: We estimated an IQR of 5900 to 10â¯300 pregnant women (median, 7800) might be infected during the initial ZIKV outbreak in Puerto Rico. Of these, an IQR of 100 to 270 infants (median, 180) may be born with microcephaly due to congenital ZIKV infection from mid-2016 to mid-2017. In the absence of a ZIKV outbreak, an IQR of 9 to 16 cases (median, 12) of congenital microcephaly are expected in Puerto Rico per year. CONCLUSIONS AND RELEVANCE: The estimate of 5900 to 10â¯300 pregnant women that might be infected with ZIKV provides an estimate for the number of infants that could potentially have ZIKV-associated adverse outcomes. Including baseline cases of microcephaly, we estimated that an IQR of 110 to 290 total cases of congenital microcephaly, mostly attributable to ZIKV infection, could occur from mid-2016 to mid-2017 in the absence of effective interventions. The primary limitation in this analysis is uncertainty in model parameters. Multivariate sensitivity analyses indicated that the cumulative incidence of ZIKV infection and risk of microcephaly given maternal infection in the first trimester were the primary drivers of both magnitude and uncertainty in the estimated number of microcephaly cases. Increased information on these parameters would lead to more precise estimates. Nonetheless, the results underscore the need for urgent actions being undertaken in Puerto Rico to prevent congenital ZIKV infection and prepare for affected infants.
Assuntos
Surtos de Doenças/prevenção & controle , Microcefalia/prevenção & controle , Microcefalia/virologia , Complicações Infecciosas na Gravidez/prevenção & controle , Infecção por Zika virus/prevenção & controle , Adulto , Feminino , Previsões , Humanos , Avaliação das Necessidades , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Porto Rico , Adulto Jovem , Zika virus/isolamento & purificação , Infecção por Zika virus/epidemiologiaRESUMO
BACKGROUND: The World Health Organization recently released recommendations stating that red blood cell (RBC) folate concentrations should be above 400 ng/L (906 nmol/L) for optimal prevention of folate-sensitive neural tube defects (NTDs). The objective of this study was to determine the distribution of folate insufficiency (FI) (<906 nmol/L) and potential risk of NTDs based on RBC folate concentrations among nonpregnant women of child-bearing age in Guatemala. METHODS: A national and regional multistage cluster probability survey was completed during 2009 to 2010 among Guatemalan women of child-bearing age 15 to 49 years of age. Demographic and health information and blood samples for RBC folate analyses were collected from 1473 women. Prevalence rate ratios of FI and predicted NTD prevalence were estimated based on RBC folate concentrations comparing subpopulations of interest. RESULTS: National FI prevalence was 47.2% [95% confidence interval, 43.3-51.1] and showed wide variation by region (18-81%). In all regions, FI prevalence was higher among indigenous (27-89%) than among nonindigenous populations (16-44%). National NTD risk based on RBC folate concentrations was estimated to be 14 per 10,000 live births (95% uncertainty interval, 11.1-18.6) and showed wide regional variation (from 11 NTDS in the Metropolitan region to 26 NTDs per 10,000 live births in the Norte region). CONCLUSION: FI remains a common problem in populations with limited access to fortified products, specifically rural, low income, and indigenous populations. However, among subpopulations that are most likely to have fortified food, the prevalence of FI is similar to countries with well-established fortification programs. Birth Defects Research (Part A) 106:587-595, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Eritrócitos/metabolismo , Deficiência de Ácido Fólico , Ácido Fólico/sangue , Defeitos do Tubo Neural/epidemiologia , Adolescente , Adulto , Feminino , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/complicações , Deficiência de Ácido Fólico/epidemiologia , Guatemala/epidemiologia , Humanos , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
OBJECTIVE: To calculate a reliable estimate of the population prevalence of Down syndrome in the US. STUDY DESIGN: The annual number of births of infants with Down syndrome were estimated by applying published birth prevalence rates of Down syndrome by maternal age to US data from the Centers for Disease Control and Prevention for the years for which births by maternal age were available (1940-2008). Death certificate data for persons with Down syndrome were available for the years 1968-2007. We estimated the number of people with Down syndrome on January 1, 2008, using a life table approach based on proportions of deaths by age. Monte Carlo sampling was used to create 90% uncertainty intervals (UIs) for our estimates. RESULTS: We estimated the January 1, 2008, population prevalence of Down syndrome as approximately 250700 (90% UI, 185900-321700) based on proportions of deaths by age from the most recent 2 years (2006-2007) of death certificate data. This estimate corresponds to a prevalence of 8.27 people with Down syndrome per 10000 population (90% UI, 6.14-10.62). CONCLUSION: Our estimate of Down syndrome prevalence is roughly 25%-40% lower than estimates based solely on current birth prevalence. The results presented here can be considered a starting point for facilitating policy and services planning for persons with Down syndrome.
Assuntos
Síndrome de Down/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Centers for Disease Control and Prevention, U.S. , Criança , Pré-Escolar , Síndrome de Down/mortalidade , Feminino , Humanos , Lactente , Masculino , Idade Materna , Pessoa de Meia-Idade , Método de Monte Carlo , Prevalência , Estados Unidos/epidemiologia , Adulto JovemRESUMO
OBJECTIVE: To estimate the population impact of child mortality as a result of cystic fibrosis (CF) potentially preventable by newborn screening. STUDY DESIGN: A systematic literature review of mortality in children with classic CF without meconium ileus (MI) in screened and unscreened cohorts was extended by contacting investigators for unpublished data. In addition, survival in US states with and without newborn screening (NBS) programs for CF was compared using data from the Cystic Fibrosis Foundation Patient Registry (CFFPR). RESULTS: Among non-US studies, CF-related mortality risk to approximately 10 years of age was lower by 5 to 10 per 100 in screened cohorts. Unpublished US data from a trial of NBS for CF indicate no CF-related deaths to 10 years of age in either cohort. CFFPR data suggest improved survival among children with CF born in US states with NBS, with a CF-related mortality difference to 10 years of age between the screened and unscreened groups between 1.5 and 2 per 100 children with CF without MI. CONCLUSION: In addition to improving nutritional outcomes, newborn screening for CF may result in improved child survival. The absolute differential in mortality risk, although modest in size, appears comparable to NBS for certain other genetic disorders.