A Bayesian analysis of the 2009 decline in tuberculosis morbidity in the United States.

Although annual data are commonly used to model linear trends and changes in trends of disease incidence, monthly data could provide additional resolution for statistical inferences. Because monthly data may exhibit seasonal patterns, we need to consider seasonally adjusted models, which can be theoretically complex and computationally intensive. We propose a combination of methods to reduce the complexity of modeling seasonal data and to provide estimates for a change in trend when the timing and magnitude of the change are unknown. To assess potential changes in trend, we first used autoregressive integrated moving average (ARIMA) models to analyze the residuals and forecast errors, followed by multiple ARIMA intervention models to estimate the timing and magnitude of the change. Because the variable corresponding to time of change is not a statistical parameter, its confidence bounds cannot be estimated by intervention models. To model timing of change and its credible interval, we developed a Bayesian technique. We avoided the need for computationally intensive simulations by deriving a closed form for the posterior distribution of the time of change. Using a combination of ARIMA and Bayesian methods, we estimated the timing and magnitude of change in trend for tuberculosis cases in the United States. Published 2012. This article is a US Government work and is in the public domain in the USA.

Confidence intervals and statistical testing for ratio measures of percent change.

In public health and medical research, ratio measures of percent change relative to baseline are often used to express a change in disease incidence. Estimating variance becomes more complex when the comparison is to an expectation based on previous data (E), rather than to an observed value (O). In 2009, the decline in reported tuberculosis (TB) cases was the largest single-year decrease since national TB surveillance began in 1953. To investigate the 2009 TB decline compared with expected counts, we analyzed TB cases reported to the Center for Disease Control and Prevention's National Tuberculosis Surveillance System. We log-transformed case counts for 2000-2008, and performed linear regression stratified by patient and clinical characteristics. We calculated relative declines from expectation as (O - E) ∕ E for patient subgroups, and constructed 95% confidence intervals for TB declines. We then formulated a Z-score test statistic comparing declines across patient subgroups under the null hypothesis that the difference of the two ratio measures was zero. We illustrate our methods by comparing 2009 declines from expectation for US-born versus foreign-born patients. Predicted values and confidence intervals assessed the magnitude of unexpected TB declines within patient groups, while statistical tests comparing ratio measures evaluated relative TB declines across groups. Published 2012. This article is a US Government work and is in the public domain in the USA.

Unexpected decline in tuberculosis cases coincident with economic recession - United States, 2009.

BACKGROUND: Since 1953, through the cooperation of state and local health departments, the U.S. Centers for Disease Control and Prevention (CDC) has collected information on incident cases of tuberculosis (TB) disease in the United States. In 2009, TB case rates declined -11.4%, compared to an average annual -3.8% decline since 2000. The unexpectedly large decline raised concerns that TB cases may have gone unreported. To address the unexpected decline, we examined trends from multiple sources on TB treatment initiation, medication sales, and laboratory and genotyping data on culture-positive TB. METHODS: We analyzed 142,174 incident TB cases reported to the U. S. National Tuberculosis Surveillance System (NTSS) during January 1, 2000-December 31, 2009; TB control program data from 59 public health reporting areas; self-reported data from 50 CDC-funded public health laboratories; monthly electronic prescription claims for new TB therapy prescriptions; and complete genotyping results available for NTSS cases. Accounting for prior trends using regression and time-series analyses, we calculated the deviation between observed and expected TB cases in 2009 according to patient and clinical characteristics, and assessed at what point in time the deviation occurred. RESULTS: The overall deviation in TB cases in 2009 was -7.9%, with -994 fewer cases reported than expected (P < .001). We ruled out evidence of surveillance underreporting since declines were seen in states that used new software for case reporting in 2009 as well as states that did not, and we found no cases unreported to CDC in our examination of over 5400 individual line-listed reports in 11 areas. TB cases decreased substantially among both foreign-born and U.S.-born persons. The unexpected decline began in late 2008 or early 2009, and may have begun to reverse in late 2009. The decline was greater in terms of case counts among foreign-born than U.S.-born persons; among the foreign-born, the declines were greatest in terms of percentage deviation from expected among persons who had been in the United States less than 2 years. Among U.S.-born persons, the declines in percentage deviation from expected were greatest among homeless persons and substance users. Independent information systems (NTSS, TB prescription claims, and public health laboratories) reported similar patterns of declines. Genotyping data did not suggest sudden decreases in recent transmission. CONCLUSIONS: Our assessments show that the decline in reported TB was not an artifact of changes in surveillance methods; rather, similar declines were found through multiple data sources. While the steady decline of TB cases before 2009 suggests ongoing improvement in TB control, we were not able to identify any substantial change in TB control activities or TB transmission that would account for the abrupt decline in 2009. It is possible that other multiple causes coincident with economic recession in the United States, including decreased immigration and delayed access to medical care, could be related to TB declines. Our findings underscore important needs in addressing health disparities as we move towards TB elimination in the United States.

Assessment of early mitigation measures against COVID-19 in Puerto Rico: March 15-May 15, 2020.

On March 15, 2020 Puerto Rico implemented non-pharmaceutical interventions (NPIs), including a mandatory curfew, as part of a state of emergency declaration to prevent the community transmission of the SARS-CoV-2 virus. The strict enforcement of this curfew was extended through May 25, with a gradual relaxation beginning on May 1. This report summarizes an assessment of these early mitigation measures on the progression of the COVID-19 pandemic in the island. From March 15 to May 15, 2020, 70,656 results of molecular (RT-PCR) tests were reported to the Puerto Rico Department of Health. Of these, 1,704 were positive, corresponding to 1,311 individuals with COVID-19 included in the study. We derived the epidemic growth rates (r) and the corresponding reproductive numbers (R) from the epidemic curve of these 1,311 individuals with laboratory-confirmed diagnosis of COVID-19 using their date of test collection as a proxy for symptoms onset. Through May 31, 2020, there were 143 COVID-19 associated deaths in Puerto Rico, for a case fatality risk of 10.9%. We compared the observed cases and deaths with Gompertz model projections had the mitigation measures not been implemented. The number of daily RT-PCR-confirmed cases peaked on March 30 (85 cases), showing a weekly cyclical trend, with lower counts on weekends and a decreasing secular trend since March 30. The initial exponential growth rate (r) was 15.87% (95% CI: 7.59%, 24.15%), corresponding to R of 1.82 (95% CI:1.37, 2.30). After March 30, the r value reverted to an exponential decay rate (negative) of -2.95% (95% CI: -4.99%, -0.92%), corresponding to R of 0.93 (95% CI: 0.86, 0.98). We estimate that, had the initial growth rate been maintained, a total of 6,155 additional COVID-19 cases would have occurred by May 15, with 211 additional COVID-19 deaths by May 31. These findings are consistent with very effective implementation of early NPIs as mitigation measures in Puerto Rico. These results also provide a baseline to assess the impact of the transition from mitigation to subsequent containment stages in Puerto Rico.

Improved program activities are associated with decreasing tuberculosis incidence in the United States.

OBJECTIVE: This study was conducted to determine whether improvements in tuberculosis (TB) program activities correlate with incident TB cases. METHODS: National TB surveillance data and program data from patients with pulmonary and laryngeal TB and their contacts were collected. These data were analyzed using regression models to assess the association between changes in incident TB cases and indicators of program performance (a time series of percent changes in program indices). RESULTS: A total of 1,361,113 contacts exposed to 150,668 TB patients were identified through contact investigations. From 1987 to 1992 (the period of TB resurgence and antedating increased funding), there was a decline in several measures used by TB programs for outcomes of contact investigations. From 1993 to 1998 (the period after increases in TB funds), there was an observable improvement in the program indices. Four program indices for contacts and two for TB cases (directly observed therapy and completion of therapy) were statistically associated (p < or = .01) with the decline in TB incident cases. CONCLUSIONS: These analyses suggest that expanded TB program activities resulted in the reduction in national TB cases and underscore the importance of treatment completion for TB disease and latent TB infection. Based on these results, we propose that further improvements in these activities will accelerate the decline of TB in the United States.

Tuberculosis transmission in nontraditional settings: a decision-tree approach.

BACKGROUND: Tuberculosis (TB) transmission in nontraditional settings and relationships (non-TSR) often eludes detection by conventional contact investigation and is increasingly common. The U.S.-based National Tuberculosis Genotyping and Surveillance Network collected epidemiologic data and genotyping results of Mycobacterium tuberculosis isolates from 1996 to 2000. METHODS: In 2003-2004, we determined the number and characteristics of TB patients in non-TSR that were involved in recent transmission, generated a decision tree to profile those patients, and performed a case-control study to identify predictors of being in non-TSR. RESULTS: Of 10,844 culture-positive reported TB cases that were genotyped, 4724 (43.6%) M. tuberculosis isolates were clustered with at least one other isolate. Among these, 520 (11%) had epidemiologic linkages discovered during conventional contact investigation or cluster investigation and confirmed by genotyping results. The decision tree identified race/ethnicity (non-Hispanic white or black) as having the greatest predictive ability to determine patients in non-TSR, followed by being aged 15 to 24 years and having positive or unknown HIV infection status. From the 520, 85 (16.4%) had non-TSR, and 435 (83.6%) had traditional settings and relationships (TSR). In multivariate analyses, patients in non-TSR were significantly more likely than those in TSR to be non-Hispanic white (adjusted odds ratio [aOR]=6.1; 95% confidence interval [CI]=1.7-21.1]) or to have an M. tuberculosis isolate resistant to rifampin (aOR=5.2; 95% CI=1.5-17.7). CONCLUSIONS: Decision-tree analyses can be used to enhance both the efficiency and effectiveness of TB prevention and control activities in identifying patients in non-TSR.

Mercurio en el cabello de embarazadas y madres lactantes chilenas / Mercury in the hair of pregnant and lactating Chilean women

Las aguas costeras de la Octava Región de Chile recibieron durante aproximadamente dos décadas desechos de mercurio de origen industrial. El objetivo del presente estudio, efectuado de 1991 a 1993, fue medir las concentraciones de mercurio en el cabello de mujeres embarazadas o lactantes de aldeas del litoral y del interior de esa región para examinar la relación entre la concentración de mercurio y el consumo de productos de mar, determinado por encuesta. En el cuestionario de encuesta usado en 1991 no se investigó la frecuencia del consumo de pescados, mariscos y algas y solo se tomaron en cuenta embarazadas y madres lactantes con un consumo mínimo semanal de una comida a base de pescado. En el cuestionario aplicado en 1992 y 1993 se investigó el consumo diario y semanal de productos marinos en general (pescado, mariscos o algas marinas). Mediante espectrofotometría se determinó la concentración de mercurio total en muestras de 100 mg de cabello de 153 mujeres embarazadas y lactantes de 11 aldeas de la Octava Región donde se consumían productos marinos con regularidad. Ninguna de las mujeres tenía exposición ocupacional al mercurio. También se determinó la concentración de mercurio total en muestras similares de cabello de mujeres de un grupo testigo compuesto de 26 embarazadas y lactantes de Pinto y el Carmen, aldeas en el interior de la misma región donde muy raras veces se comen productos de mar. La medida aritmética de las concentraciones capilares de mercurio total fue de 1,81 mg/kg de peso corporal para el grupo de estudio (con una desviación estándar (DE) de 1,52) y de 0,42 mg/kg para el grupo del interior (con una DE de 0,15), diferencia estadísticamente significativa (P0,01). También se observo una diferencia estadísticamente significativa (P0,05) entre la media del grupo del interior y la de las nueve aldeas más cercanas a las fuentes de contaminación, pero no entre aquella y la de las mujeres de las dos aldeas en los extremos norte y sur de la zona de estudio, que estaban más lejos de las aguas contaminadas. La concentración capilar de mercurio total fue significativamente mayor en las mujeres que indicaron comer pescado siete veces a la semana o más; en las que indicaron comer pescado, mariscos o algas cinco veces a la semana o más, y en las que habían vivido 20 años o más en su aldea. No se encontro ninguna diferencia estadísticamente significativa cuando los resultados se analizaron por edad

Evaluation of a regionalized perinatal care system through linked infant birth and death certificates: Puerto Rico 1980-84

En Puerto Rico las tasas de mortalidad neonatal por peso al nacer se encuentran entre las más altas documentadas en los Estados Unidos. Més, aún, desde 1979, la mortalidad neonatal en Puerto Rico ha sobrepasado la mortalidad neonatal de la población negra en los Estados Unidos. Dado que la proporción de nacimientos de menos de 2,500 gramos se ha mantenido relativamente estable en los últimos 10 a 15 años tanto en Puerto Rico como en los Estados Unidos continentales, estos hallazgos sugieren problemas de acceso o problemas en la calidad del cuidado neonatal en Puerto Rico. Por lo tanto, utilizamos certificados computerizados de nacimiento pareados con sus correspondientes certificados de defunción durante el período de 1980 a 1984 para poder así evaluar la regionalización de los servicios perinatales en la isla. Encontramos que el 41.6% de todos los nacimientos de menos de 1,500 gramos ocurrieron en hospitales sin Unidad de Cuidado Intensivo Neonatal (UCIN). Además, el nacer en un hospital con UCIN no estuvo asociado con una mayor sobrevivencia en infantes de menos de 2,500 gramos. Aún luego de ajustar por el peso al nacer, por la puntuación Apgar a los 5 minutos y por historial de alguna complicación en el embarazo, no pudimos documentar una mayor sobrevivencia en los nacimientos de los hospitales con UCIN. Concluimos que la regionalizaición de servicios perinatales en la isla necesita reevaluación y recomendamos la implementación de medidas preventivas de primera, segunda y tercera ...

Evaluation of a regionalized perinatal care system through linked infant birth and death certificates: Puerto Rico, 1980-84

En Puerto Rico las tasas de mortalidad neonatal por peso al nacer se encuentran entre las más altas documentadas en los Estados Unidos. Más aún, desde 1979, la mortalidad neonatal en Puerto Rico ha sobrepasado la mortalidad neonatal de la población negra en los Estados Unidos. Dado que la proporción de nacimientos de menos de 2,500 gramos se ha mantenido relativamente estable en los últimos 10 a 15 años tanto en Puerto Rico como en los Estados Unidos continentales, estos hallazgos sugieren problemas de acceso o problemas en al calidad del cuidado neonatal en Puerto Rico. Por lo tanto, utilizamos certificados computerizados de nacimiento pareados con sus correspondientes certificados de defunción durante el período de 1980 a 1984 para poder así evaluar la regionalización de los servicios perinatales en al isla. Encontramos que el 41.6% de todos los nacimientos de menos de 1,500 gramos ocurrieron en hospitales sin Unidad de Cuidado Intensivo Neonatal (UCIN). Además, el nacer en un hospital con UCIN no estuvo asociado con una mayor sobrevivencia en infantes de menos de 2,500 gramos. Aún luego de ajustar por el peso al nacer, por la puntación Apgar a los 5 minutos y por historial de alguna complicación en el embarazo, no pudimos documentar una mayor sobrevivencia en los nacimientos de los hospitales con UCIN. Concluimos que la regionalización de servicios perinatales en la isla necesita reevaluación y recomendamos la implementación de medidas preventivas de primera, segunda y tercera instancia

Reducción de la morbilidad y mortalidad materna en las Américas: guía para la vigilancia epidemiologica de la muerte materma / Reduction of maternal morbility and mortality in the Americas: guidelines for epidemiological surveillance on maternal mortality

Esta Guía presenta los lineamientos generales para la vigilancia epidemiológica de la muerte materna. El objeto principal del Sistema de Vigilancia de la Mortalidad Materna (SVEMM) es contribuir al mejor conocimiento de los factores médicos-sociales que determinan las muertes maternas y proveer información para el desarrollo de estrategias para mejorar la salud de la mujer

El propósito principal de esta Guía es ofrecer a los paíse en una forma resumida, y lenguaje simple, las orientaciones más importatnes para establecer un SVEMM o perfeccionarlo en aquellos países que ya cuenten con él

Reduccion de la morbilidad y mortalidad materna en las Américas: guia para la vigilancia epidemiologica de la muerte materma / Reduction of maternal morbility and mortality in the Américas: guidelines for epidemiological surveillance on maternal mortality

Esta Guia presenta los lineamientos generales para la vigilancia epidemiologica de la muerte materna. El objeto principal del Sistema de Vigilancia de la Mortalidad Materna (SVEMM) es contribuir al mejor conocimiento de los factores medicos-sociales que determinan las muertes maternas y proveer informacion para el desarrollo de estrategias para mejorar la salud de la mujerEl proposito principal de esta Guia es ofrecer a los paise en una forma resumida, y lenguaje simple, las orientaciones mas importantes para establecer un SVEMM o perfeccionarlo en aquellos países que ya cuenten con el