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People with sickle cell disease (SCD) suffer from numerous acute complications that can result in multiple hospitalizations and emergency department (ED) and outpatient care visits. Priapism, a prolonged unwanted erection of the penis not due to sexual stimulation, is a serious complication among males with SCD. Variations in estimates of prevalence make it difficult to accurately assess the burden of this complication of SCD. We analyzed data from the Nationwide Emergency Department Sample (NEDS), a product of the Healthcare Cost and Utilization Project, for the years 2006 through 2010 to measure the numbers of ED visits and to examine patterns of subsequent hospitalizations associated with priapism among male patients with SCD. We find that among ED visits associated with males with SCD, those prompted by priapism are more likely to result in hospitalization than are those associated with pain.  相似文献   

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Background

In patients with HIV and tuberculosis (TB) in resource-constrained settings, smear-negative disease has been associated with higher mortality than smear-positive disease. Higher reported mortality may be due to misdiagnosis, diagnostic delays, or because smear-negative disease indicates more advanced immune suppression.

Methods

We analyzed culture-confirmed, pulmonary TB among patients with TB and HIV in the United States from 1993–2008 to calculate prevalence ratios (PRs) for smear-negative disease by demographic and clinical characteristics. Allowing two years for treatment outcome to be reported, we determined hazard ratios (HRs) for survival by smear status, adjusted for significant covariates on patients before 2006.

Results

Among 16,710 cases with sputum smear results, 6,739 (39%) were sputum smear-negative and 9,971 (58%) were sputum smear-positive. The prevalence of smear-negative disease was lower in male patients (PR: 0.89, 95% confidence interval [CI]: 0.86–0.93) and in those who were homeless (PR: 0.92, CI: 0.87–0.97) or used alcohol excessively (PR: 0.91, CI: 0.87–0.95), and higher in persons diagnosed while incarcerated (PR: 1.20, CI: 1.13–1.27). Patients with smear-negative disease had better survival compared to patients with smear-positive disease, both before (HR: 0.82, CI: 0.75–0.90) and after (HR: 0.81, CI: 0.71–0.92) the introduction of combination anti-retroviral therapy.

Conclusions

In the United States, smear-negative pulmonary TB in patients with HIV was not associated with higher mortality, in contrast to what has been documented in high TB burden settings. Smear-negative TB can be routinely and definitively diagnosed in the United States, whereas high-burden countries often rely solely on AFB-smear microscopy. This difference could contribute to diagnostic and treatment delays in high-burden countries, possibly resulting in higher mortality.  相似文献   

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Fusarium commune can cause damping‐off and root rot of conifer seedlings in forest nurseries, and this pathogen has been previously reported from Oregon, Idaho, and Washington, USA. We collected Fusarium isolates from additional nurseries in the midwestern and western USA to more fully determine occurrence of this pathogen. We used DNA sequences of the mitochondrial small subunit gene to identify F. commune. In addition to confirming the occurrence of Fcommune in Oregon, Idaho, and Washington, USA, we also discovered that Fcommune is even more widespread with this first report of Fcommune occurring in Nevada, Montana, Nebraska, and Michigan, USA.  相似文献   

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Analysis of trends in the suburbanization of whites, blacks, Asians, and Hispanics reveal that all groups are becoming more suburbanized, though the gap between whites and minorities remains large. Although central cities have made the transition to a majority-minority configuration, suburbs are still overwhelmingly white. Levels of minority-white segregation are nonetheless lower in suburbs than in cities. Blacks remain the most segregated group at both locations. Black segregation and isolation levels are declining in cities and suburbs; however, while Hispanic and Asian segregation levels have remained stable, spatial isolation levels have risen. Multivariate analyses suggest that Hispanics achieve desegregation indirectly by using socio-economic achievements to gain access to less-segregated suburban communities and directly by translating their status attainments into residence in white neighbourhoods. Blacks do not achieve desegregation indirectly through suburbanization and they are much less able than Hispanics to use their socio-economic attainments directly to enter white neighbourhoods.  相似文献   

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Introduction

We describe characteristics of unplanned school closures (USCs) in the United States over two consecutive academic years during a non-pandemic period to provide context for implementation of school closures during a pandemic.

Methods

From August 1, 2011 through June 30, 2013, daily systematic internet searches were conducted for publicly announced USCs lasting ≥1 day. The reason for closure and the closure dates were recorded. Information on school characteristics was obtained from the National Center for Education Statistics.

Results

During the two-year study period, 20,723 USCs were identified affecting 27,066,426 students. Common causes of closure included weather (79%), natural disasters (14%), and problems with school buildings or utilities (4%). Only 771 (4%) USCs lasted ≥4 school days. Illness was the cause of 212 (1%) USCs; of these, 126 (59%) were related to respiratory illnesses and showed seasonal variation with peaks in February 2012 and January 2013.

Conclusions

USCs are common events resulting in missed school days for millions of students. Illness causes few USCs compared with weather and natural disasters. Few communities have experience with prolonged closures for illness.  相似文献   

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Anecdotal accounts regarding reduced US cropping system diversity have raised concerns about negative impacts of increasingly homogeneous cropping systems. However, formal analyses to document such changes are lacking. Using US Agriculture Census data, which are collected every five years, we quantified crop species diversity from 1978 to 2012, for the contiguous US on a county level basis. We used Shannon diversity indices expressed as effective number of crop species (ENCS) to quantify crop diversity. We then evaluated changes in county-level crop diversity both nationally and for each of the eight Farm Resource Regions developed by the National Agriculture Statistics Service. During the 34 years we considered in our analyses, both national and regional ENCS changed. Nationally, crop diversity was lower in 2012 than in 1978. However, our analyses also revealed interesting trends between and within different Resource Regions. Overall, the Heartland Resource Region had the lowest crop diversity whereas the Fruitful Rim and Northern Crescent had the highest. In contrast to the other Resource Regions, the Mississippi Portal had significantly higher crop diversity in 2012 than in 1978. Also, within regions there were differences between counties in crop diversity. Spatial autocorrelation revealed clustering of low and high ENCS and this trend became stronger over time. These results show that, nationally counties have been clustering into areas of either low diversity or high diversity. Moreover, a significant trend of more counties shifting to lower rather than to higher crop diversity was detected. The clustering and shifting demonstrates a trend toward crop diversity loss and attendant homogenization of agricultural production systems, which could have far-reaching consequences for provision of ecosystem system services associated with agricultural systems as well as food system sustainability.  相似文献   

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Importance and Objective

Prior influenza infection is a risk factor for invasive meningococcal disease. Quantifying the fraction of meningococcal disease attributable to influenza could improve understanding of viral-bacterial interaction and indicate additional health benefits to influenza immunization.

Design, Setting and Participants

A time series analysis of the association of influenza and meningococcal disease using hospitalizations in 9 states from 1989–2009 included in the State Inpatient Databases from the Agency for Healthcare Research and Quality and the proportion of positive influenza tests by subtype reported to the Centers for Disease Control. The model accounts for the autocorrelation of meningococcal disease and influenza between weeks, temporal trends, co-circulating respiratory syncytial virus, and seasonality. The influenza-subtype-attributable fraction was estimated using the model coefficients. We analyzed the synchrony of seasonal peaks in hospitalizations for influenza, respiratory syncytial virus, and meningococcal disease.

Results and Conclusions

In 19 of 20 seasons, influenza peaked≤2 weeks before meningococcal disease, and peaks were highly correlated in time (ρ = 0.95; P <.001). H3N2 and H1N1 peaks were highly synchronized with meningococcal disease while pandemic H1N1, B, and respiratory syncytial virus were not. Over 20 years, 12.8% (95% CI, 9.1–15.0) of meningococcal disease can be attributable to influenza in the preceding weeks with H3N2 accounting for 5.2% (95% CI, 3.0–6.5), H1N1 4.3% (95% CI, 2.6–5.6), B 3.0% (95% CI, 0.8–4.9) and pH1N1 0.2% (95% CI, 0–0.4). During the height of influenza season, weekly attributable fractions reach 59%. While vaccination against meningococcal disease is the most important prevention strategy, influenza vaccination could provide further protection, particularly in young children where the meningococcal disease vaccine is not recommended or protective against the most common serogroup.  相似文献   

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Background

Assessment of cancer incidence trends within the U.S. have mostly relied upon Surveillance, Epidemiology, and End Results (SEER) data, with implicit inference that such is representative of the general population. However, many cancer policy decisions are based at a more granular level. To help inform such, analyses of regional cancer incidence data are needed. Leveraging the unique resource of National Program of Cancer Registries (NPCR)-SEER, we assessed whether regional rates and trends of esophageal cancer significantly deviated from national estimates.

Methods

From NPCR-SEER, we extracted cancer case counts and populations for whites aged 45–84 years by calendar year, histology, sex, and census region for the period 1999–2008. We calculated age-standardized incidence rates (ASRs), annual percent changes (APCs), and male-to-female incidence rate ratios (IRRs).

Results

This analysis included 65,823 esophageal adenocarcinomas and 27,094 esophageal squamous cell carcinomas diagnosed during 778 million person-years. We observed significant geographic variability in incidence rates and trends, especially for esophageal adenocarcinomas in males: ASRs were highest in the Northeast (17.7 per 100,000) and Midwest (18.1). Both were significantly higher than the national estimate (16.0). In addition, the Northeast APC was 62% higher than the national estimate (3.19% vs. 1.97%). Lastly, IRRs remained fairly constant across calendar time, despite changes in incidence rates.

Conclusion

Significant regional variations in esophageal cancer incidence trends exist in the U.S. Stable IRRs may indicate the predominant factors affecting incidence rates are similar in men and women.  相似文献   

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Abstract: After roughly a 60-year absence, wolves (Canis lupus) immigrated (1979) and were reintroduced (1995-1996) into the northern Rocky Mountains (NRM), USA, where wolves are protected under the Endangered Species Act. The wolf recovery goal is to restore an equitably distributed metapopulation of ≥30 breeding pairs and 300 wolves in Montana, Idaho, and Wyoming, while minimizing damage to livestock; ultimately, the objective is to establish state-managed conservation programs for wolf populations in NRM. Previously, wolves were eradicated from the NRM because of excessive human killing. We used Andersen–Gill hazard models to assess biological, habitat, and anthropogenic factors contributing to current wolf mortality risk and whether federal protection was adequate to provide acceptably low hazards. We radiocollared 711 wolves in Idaho, Montana, and Wyoming (e.g., NRM region of the United States) from 1982 to 2004 and recorded 363 mortalities. Overall, annual survival rate of wolves in the recovery areas was 0.750 (95% CI = 0.728-0.772), which is generally considered adequate for wolf population sustainability and thereby allowed the NRM wolf population to increase. Contrary to our prediction, wolf mortality risk was higher in the northwest Montana (NWMT) recovery area, likely due to less abundant public land being secure wolf habitat compared to other recovery areas. In contrast, lower hazards in the Greater Yellowstone Area (GYA) and central Idaho (CID) likely were due to larger core areas that offered stronger wolf protection. We also found that wolves collared for damage management purposes (targeted sample) had substantially lower survival than those collared for monitoring purposes (representative sample) because most mortality was due to human factors (e.g., illegal take, control). This difference in survival underscores the importance of human-caused mortality in this recovering NRM population. Other factors contributing to increased mortality risk were pup and yearling age class, or dispersing status, which was related to younger age cohorts. When we included habitat variables in our analysis, we found that wolves having abundant agricultural and private land as well as livestock in their territory had higher mortality risk. Wolf survival was higher in areas with increased wolf density, implying that secure core habitat, particularly in GYA and CID, is important for wolf protection. We failed to detect changes in wolf hazards according to either gender or season. Maintaining wolves in NWMT will require greater attention to human harvest, conflict resolution, and illegal mortality than in either CID or GYA; however, if human access increases in the future in either of the latter 2 areas hazards to wolves also may increase. Indeed, because overall suitable habitat is more fragmented and the NRM has higher human access than many places where wolves roam freely and are subject to harvest (e.g., Canada and AK), monitoring of wolf vital rates, along with concomitant conservation and management strategies directed at wolves, their habitat, and humans, will be important for ensuring long-term viability of wolves in the region.  相似文献   

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Noroviruses and other viral pathogens are increasingly recognized as frequent causes of acute gastroenteritis (AGE). However, few laboratory-based data are available on the incidence of AGE caused by viral pathogens in the U.S. This study examined stool specimens submitted for routine clinical diagnostics from patients enrolled in Kaiser Permanente (KP) health plans in metro Portland, OR, and the Maryland, District of Columbia, and northern Virginia geographic areas to estimate the incidence of viral enteropathogens in these populations. Over a one-year study period, participating laboratories randomly selected stools submitted for routine clinical diagnostics for inclusion in the study along with accompanying demographic and clinical data. Selected stools were tested for norovirus, rotavirus, sapovirus, and astrovirus using standardized real-time RT-PCR protocols. Each KP site provided administrative data which were used in conjunction with previously published data on healthcare utilization to extrapolate pathogen detection rates into population-based incidence rates. A total of 1,099 specimens collected during August 2012 to September 2013 were included. Mean age of patients providing stool specimens was 46 years (range: 0–98 years). Noroviruses were the most common viral pathogen identified among patients with AGE (n = 63 specimens, 6% of specimens tested). In addition, 22 (2%) of specimens were positive for rotavirus; 19 (2%) were positive for sapovirus; and 7 (1%) were positive for astrovirus. Incidence of norovirus-associated outpatient visits was 5.6 per 1,000 person-years; incidence of norovirus disease in the community was estimated to be 69.5 per 1,000 person-years. Norovirus incidence was highest among children <5 years of age (outpatient incidence = 25.6 per 1,000 person-years; community incidence = 152.2 per 1,000 person-years), followed by older adults aged >65 years (outpatient incidence = 7.8 per 1,000 person-years; community incidence = 75.8 per 1,000 person-years). Outpatient incidence rates of rotavirus, sapovirus, and astrovirus were 2.0, 1.6, 0.6 per 1,000 person-years, respectively; community incidence rates for these viruses were 23.4, 22.5, and 8.5 per 1,000 person-years, respectively. This study provides the first age-group specific laboratory-based community and outpatient incidence rates for norovirus AGE in the U.S. Norovirus was the most frequently detected viral enteropathogen across the age spectrum with the highest rates of norovirus disease observed among young children and, to a lesser extent, the elderly. These data provide a better understanding of the norovirus disease burden in the United States, including variations within different age groups, which can help inform the development, targeting, and future impacts of interventions, including vaccines.  相似文献   

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While from a late twentieth- and early twenty-first century perspective, the ideologies of eugenics (controlled reproduction to eliminate the genetically unfit and promote the reproduction of the genetically fit) and environmental conservation and preservation, may seem incompatible, they were promoted simultaneously by a number of figures in the progressive era in the decades between 1900 and 1950. Common to the two movements were the desire to preserve the “best” in both the germ plasm of the human population and natural environments (including not only natural resources, but also undisturbed nature preserves such as state and national parks and forests). In both cases advocates sought to use the latest advances in science to bolster and promote their plans, which in good progressive style, involved governmental planning and social control. This article explores the interaction of eugenic and conservationist ideologies in the careers of Sacramento banker and developer Charles M. Goethe and his friend and mentor, wealthy New York lawyer Madison Grant. In particular, the article suggests how metaphors of nature supported active work in both arenas.  相似文献   

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Land-cover changes in the Choptank basin were estimated for 1665–1820 by using historical socioeconomic data and crop-rotation models. Socioeconomic data (human population, output per laborer, and crop yields) were obtained from the literature, whereas crop-rotation models, based on historical records, represented how agriculture was practiced. Model parameters and output were validated with export records, census data, and other historical records, and model errors were estimated to be approximately 5%. This approach indicated a sigmoidal pattern for conversion of primary forest to agricultural land by 1800. The initial time period, 1665–1720, was characterized by low-intensity tobacco and corn cultivation. Due to long fallows, the models indicated that there was little land in crops (approximately 5% of the region), but larger areas of secondary forest occurred on former cropland (approximately 15%). Although primary forest decreased, the initial result in the first 55 years was a low net rate of deforestation and occupation by low-intensity farms. However, after 1720, cropland expanded rapidly due to the use of wheat as a cash crop. From 1720 to 1775, primary and secondary forest rapidly disappeared, increasing agricultural land to 60% of the region. By 1800, approximately 80% was estimated to be converted to agriculture, and little primary forest remained. After 1800, the land needed for crops decreased due to improved management practices and crop yields, and some secondary forest on formerly cleared agricultural sites may have reappeared. We estimate that less than 150 years of European colonization resulted in virtually complete agriculturalization of a primarily forested landscape.  相似文献   

18.

Context

The goal of influenza vaccination programs is to reduce influenza-associated disease outcomes. Therefore, estimating the reduced burden of influenza as a result of vaccination over time and by age group would allow for a clear understanding of the value of influenza vaccines in the US, and of areas where improvements could lead to greatest benefits.

Objective

To estimate the direct effect of influenza vaccination in the US in terms of averted number of cases, medically-attended cases, and hospitalizations over six recent influenza seasons.

Design

Using existing surveillance data, we present a method for assessing the impact of influenza vaccination where impact is defined as either the number of averted outcomes or as the prevented disease fraction (the number of cases estimated to have been averted relative to the number of cases that would have occurred in the absence of vaccination).

Results

We estimated that during our 6-year study period, the number of influenza illnesses averted by vaccination ranged from a low of approximately 1.1 million (95% confidence interval (CI) 0.6–1.7 million) during the 2006–2007 season to a high of 5 million (CI 2.9–8.6 million) during the 2010–2011 season while the number of averted hospitalizations ranged from a low of 7,700 (CI 3,700–14,100) in 2009–2010 to a high of 40,400 (CI 20,800–73,000) in 2010–2011. Prevented fractions varied across age groups and over time. The highest prevented fraction in the study period was observed in 2010–2011, reflecting the post-pandemic expansion of vaccination coverage.

Conclusions

Influenza vaccination programs in the US produce a substantial health benefit in terms of averted cases, clinic visits and hospitalizations. Our results underscore the potential for additional disease prevention through increased vaccination coverage, particularly among nonelderly adults, and increased vaccine effectiveness, particularly among the elderly.  相似文献   

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Despite the importance of education for shaping individuals’ life chances, little research has examined trends and differences in educational attainment for detailed demographic subpopulations in the United States. We use labour market segmentation and cohort replacement theories, linear regression methods, and data from the National Health Interview Survey to understand educational attainment by race/ethnicity, nativity, birth cohort, and sex between 1989 and 2005 in the United States. There have been significant changes in educational attainment over time. In support of the cohort replacement theory, we find that across cohorts, females have enjoyed greater gains in education than men, and for some race/ethnic groups, recent cohorts of women average more years of education than comparable men. And in support of labour market segmentation theories, foreign-born Mexican Americans continue to possess relatively low levels of educational attainment. Our results can aid policymakers in identifying vulnerable populations, and form the base from which to better understand changing disparities in education.  相似文献   

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