Comparative population dynamics of mosquito-borne flaviviruses.

Among the members of the genus Flavivirus are several important human pathogens, including the dengue (DEN) and Japanese encephalitis (JE) viruses. From the analysis of gene sequence data of samples of these virus populations it is possible to infer phylogenetic relationships, which in turn can yield important epidemiological information, including their demographic history in humans. In this study, we use a recently developed method, based on coalescent theory, to infer the population dynamics of a variety of mosquito-borne flaviviruses. Our study involves the testing of alternative hypotheses, the estimation of confidence intervals around demographic model parameter values, and the placing of the maximum likelihood (ML) demographic model into a "real time" epidemiological history. We reveal that all the Flavivirus populations studied are growing at an exponential rate, with the rates of population growth of dengue virus serotypes 2 and 3 increasing rapidly in the recent past, and that of Japanese encephalitis virus changing from constant population size to exponential growth within the last century. We therefore demonstrate that the use of these coalescent methods may be extremely valuable in monitoring responses to interventions such as vaccination or vector control.     

A comparison of methods for inferring causal relationships between genotype and phenotype using additional biological measurements

Genome wide association studies (GWAS) have been very successful over the last decade at identifying genetic variants associated with disease phenotypes. However, interpretation of the results obtained can be challenging. Incorporation of further relevant biological measurements (e.g. ‘omics’ data) measured in the same individuals for whom we have genotype and phenotype data may help us to learn more about the mechanism and pathways through which causal genetic variants affect disease. We review various methods for causal inference that can be used for assessing the relationships between genetic variables, other biological measures, and phenotypic outcome, and present a simulation study assessing the performance of the methods under different conditions. In general, the methods we considered did well at inferring the causal structure for data simulated under simple scenarios. However, the presence of an unknown and unmeasured common environmental effect could lead to spurious inferences, with the methods we considered displaying varying degrees of robustness to this confounder. The use of causal inference techniques to integrate omics and GWAS data has the potential to improve biological understanding of the pathways leading to disease. Our study demonstrates the suitability of various methods for performing causal inference under several biologically plausible scenarios.     

New possibilities for population control of cystic fibrosis.

Cystic fibrosis (CF), which is caused exclusively by mutation of a single gene, is inherited in autosomal recessive fashion and is the commonest such disorder in populations of Caucasian origin. Although much progress has been made during the last 50 years in its clinical management, with a corresponding improvement in the mean life expectancy in developed countries from a few months to a few decades, it remains incurable and a complete understanding of its biochemical basis is still being sought. Consequently, attention has been given to the possibility of screening for carriers of the defective gene, who represent up to 5% in some populations, so that they may be given appropriate genetic counselling. Whereas previously carriers were identified only when they became parents of affected children, in recent years carriers who were more distantly related to CF patients have often been identified by means of genetic linkage techniques. A new strategy for the control of CF at the population level is now proposed. It is based on the report of a joint WHO/ICF(M)A (International Cystic Fibrosis (Mucoviscidosis) Association) Task Force on CF which met in November 1990.     

心悦片微生物限度检查的方法学验证研究

目的建立心悦片的微生物限度检验方法。方法按《中国药典》2010年版规定,分别采用常规法、培养基稀释法对样品进行微生物限度检查;根据5株阳性对照菌的试验组、菌液组、供试品对照组结果进行方法学验证试验。结果金黄色葡萄球菌、大肠埃希菌、白色假丝酵母菌、黑曲霉菌采用常规法回收率均>70.0%,枯草芽胞杆菌黑色变种芽胞采用培养基稀释法回收率>70.0%,心悦片具有抑菌活性,培养基稀释法能有效地去除其抑菌活性。结论用培养基稀释法进行微生物限度检查,可以客观地反映药物中微生物的污染状况,以达到检测目的 。     

An unsupervised classification method for inferring original case locations from low-resolution disease maps

Background  

Widespread availability of geographic information systems software has facilitated the use of disease mapping in academia, government and private sector. Maps that display the address of affected patients are often exchanged in public forums, and published in peer-reviewed journal articles. As previously reported, a search of figure legends in five major medical journals found 19 articles from 1994–2004 that identify over 19,000 patient addresses. In this report, a method is presented to evaluate whether patient privacy is being breached in the publication of low-resolution disease maps.     

Two methods of estimating the target population for public maternity services programs.

One difficulty in estimating the target population for public health programs is identifying a current and appropriate indicator of the low-income population. Using data from Mississippi and Maryland, we determined that educational attainment of women giving birth is a feasible substitute for census data in estimating the low-income maternity population, and that vital statistics data offer several advantages for estimating the maternity services target population over census data.     

A population dynamics simulation model with application to health planning.

Despite the increasing emphasis on computers and quantitative methods in health services programs, health services administration students are denied access to many of the most powerful tools of systems analysis, including discrete event simulation, because they lack the necessary background in computer programming, simulation methodology, and stochastic processes. This article presents an approach to the modeling of the growth and decline of population groups and their attributes that can be used by students who do not have the extensive quantitative background required to develop the usual discrete event simulation models. The underlying theory, which is based on the behavior of the expectation process of vector Galton-Watson branching processes, can be explained quite easily. An example is presented that uses an age and sex specific model of population growth to investigate policy questions related to the feasibility of the construction of a long-term care facility for a defined population group. Planning decisions are based on the growth and decline of the numbers of individuals in the various age and sex groups. Extensions of the basic methodology are possible that would include projections of the variance-covariance matrix of the population sizes for each year of the projection process. In addition, the model can be extended to include projections of the impact of infectious and communicable diseases on a defined population group together with the effect of categorical disease screening and control programs. Given the basic data utilized in the model, the implementation of the calculations required by the model can be made on modern microcomputer hardware using any of the standard spreadsheet programs.     

New treatment methods for autoimmune thrombocytopenia

--For many years, splenectomy has been considered the only therapy with proven efficacy in patients with relapsed/refractory idiopathic thrombocytopenic purpura (ITP) following corticosteroid therapy. --A broad spectrum of (mostly immunosuppressive) agents are available for patients who fail to respond to splenectomy. However, the risks associated with these agents sometimes outweigh their benefits. --Recently, several new or renewed strategies have been evaluated for chronic refractory ITP. --Short-term therapy with high-dose dexamethasone is an effective alternative to long-term treatment with corticosteroids. --Depletion of B lymphocytes with rituximab, an agent that has an established role in the treatment of non-Hodgkin's lymphoma, also appears to be effective in autoimmune disorders, particularly in ITP. --Although the main problem in ITP is the increased destruction of thrombocytes, stimulation of thrombocyte production with thrombopoietin(TPO)-receptor agonists can increase thrombocyte counts. --Two TPO-receptor agonists, AMG531 and eltrombopag, induce responses in 70-80% of ITP patients and are expected to gain approval for use in ITP soon.     

应用不同微生物源追踪方法追踪水库中粪便污染来源

目的:用两种不同的微生物源追踪(Microbial source tracking,MST)方法对江苏省盱眙县桂五水库粪便污染来源进行追踪。方法:于春、夏、秋、冬4季分别采集水库周边已知来源粪便标本,分离大肠埃希菌并作为指示菌,分别建立已知源指示菌细菌基因组重复序列PCR(repetitive Extragenic Palindromic-Polymerase chain reaction,rep-PCR)特征指纹库和已知源指示菌抗生素敏感性(Antibiotic Resistance Analysis,ARA)数据库,并分别用统计分析及试验设计软件(JMP7.0软件)和基因聚类分析软件(Bionumerics 4.0软件)计算平均正确归类率(Average Rate of Correct Classification,ARCC),以检验各自的宿主来源区分效果。同期采集水样,膜过滤法分离并确认指示菌,分别进行rep-PCR扩增和ARA试验,并分别与已知源指示菌rep-PCR特征指纹库和ARA数据库进行统计学比对,判断桂五水库中粪便污染来源。结果:将已知源指示菌rep-PCR特征指纹库和ARA数据库分别分为2、...     

Bayesian methods of confidence interval construction for the population attributable risk from cross‐sectional studies

Population attributable risk measures the public health impact of the removal of a risk factor. To apply this concept to epidemiological data, the calculation of a confidence interval to quantify the uncertainty in the estimate is desirable. However, because perhaps of the confusion surrounding the attributable risk measures, there is no standard confidence interval or variance formula given in the literature. In this paper, we implement a fully Bayesian approach to confidence interval construction of the population attributable risk for cross‐sectional studies. We show that, in comparison with a number of standard Frequentist methods for constructing confidence intervals (i.e. delta, jackknife and bootstrap methods), the Bayesian approach is superior in terms of percent coverage in all except a few cases. This paper also explores the effect of the chosen prior on the coverage and provides alternatives for particular situations. Copyright © 2016 John Wiley & Sons, Ltd.     

流动人口不同方式艾滋病健康教育的效果评价

目的针对从事不同职业的流动人群,比较不同干预措施对其艾滋病的相关知识、态度和行为的影响。方法逐级整群抽样选定5组人群,其中一组为当地人群(空白对照),另4组为流动人群(流动人口空白对照组、一般干预组、积极干预组、综合干预组)。结果干预前,流动人群的艾滋病知识知晓率明显低于当地人群;干预后,3个干预组人群的知识知晓率均有显著提高(P<0·01),而空白对照组无明显变化(P>0·05)。流动人群中的建筑工人和工厂务工者,采取一般干预措施(如发放知识手册)的效果最佳;流动人群中的五小企业和娱乐行业从业者,采取综合干预措施(发放知识手册 专题讲座与当面咨询)效果最佳。干预后流动人群与艾滋病相关的态度方面有明显好转,而行为方面的改变差异无显著性。结论在流动人口中开展艾滋病健康教育时,不同行业的人群采取不同的干预措施,可有效地提高其艾滋病的相关知识、改善相关的态度,而相关行为的改变还需要有针对性的技能训练才能实现。     

Laboratory methods for evaluating early pregnancy loss in an industry-based population

Laboratory methods were adapted or developed to analyze approximately 70,000 daily urine samples collected during more than 2,500 menstrual cycles from 448 women working in the semiconductor industry. An immunoenzymometric assay (IEMA) for Human chorionic gonadotropin (hCG) was employed for screening cycles in order to optimize laboratory resources and to reduce the number of samples requiring analysis by less efficient methods. The presence of hCG in urine was confirmed by the definitive immunoradiometric assay (IRMA). The screening assay eliminated 78% of cycles from further analysis because there was no evidence of conception. Thirty-eight of 448 cycles identified as having significant levels of hCG with the IEMA were confirmed as hCG positive with the IRMA. HCG-positive cycles were further evaluated by examination of daily diary data and by laboratory assays for ovarian and pituitary hormones. As a result of these evaluations, 17 of the 38 cycles identified by the IRMA as positive for hCG were found to be nonconceptive cycles. These results demonstrate the effectiveness of screening assays for hCG, as well as the importance of using multiple urinary biomarkers for the detection of early fetal loss with daily urine samples.