共查询到20条相似文献,搜索用时 109 毫秒
1.
目的探讨累积和(CUSUM)模型在细菌性痢疾早期预警监测中的应用。方法数据来源于2007年北京市法定传染病报告系统细菌性痢疾报告数据和北京市2007年细菌性痢疾暴发疫情处理记录。预警运算使用美国CDC早期异常报告系统软件。结果 330个街道或乡镇共发出预警信息数为3743条,平均每个街道或乡镇发出11.3条预警信息,其中最少的为0条,最多的为25条,中位数为12,四分位间距为7。及时预警了2007年疫情记录中的两起细菌性痢疾暴发。结论累积和模型运算过程简单,预警频次和因预警产生的审核、流调工作量均在可接受范围内,可以应用在日常细菌性痢疾监测和防控工作中。 相似文献
2.
目的 探究适合湖北省潜江市手足口病的预警模型并比较预警功效,为自动预警提供技术支持。方法 利用湖北省潜江市2013年4月1日-2014年3月31日的手足口病数据和模拟暴发数据对Shewhart模型、移动平均模型(MA)、指数加权移动平均(EWMA)、累计和控制图(CUSUM)以及早期异常探测系统(EARS'C1、C2、C3)预警模型进行比较。通过改变预警阈值水平,比较各预警模型在不同模拟暴发数据下的约登指数和平均检出时间(DT)。结果 对于不同参数的模拟暴发数据,暴发的强度越大,预警模型的约登指数越高,平均DT越短;而暴发的持续时间越长,预警模型的约登指数越高,平均DT却有所延长。综合9种不同强度及持续时间的模拟暴发评价结果,发现在预警阈值为0.5时各模型功效最优。此时,Shewhart的约登指数和平均DT为0.57、1.12 d;MA为0.58、2.62 d;EWMA为0.44、3.70 d;CUSUM为0.46、3.56 d;EARS'C1为0.59、2.43 d;EARS'C2为0.57、2.47 d;EARS'C3为0.55、2.20 d。结论 Shewhart模型更适合于潜江地区手足口病的预警。 相似文献
3.
4.
应用2005--2011年北京市猩红热报告病例数据,探讨累积和(cusuM)模型在探测猩红热流行起始时间的应用价值。采用Excel软件建立C1一MILD(C1)、C2一MEDIUM(C2)和C3一ULTRA(C3)模型,比较不同参数组合下C1一c3模型的Youden(YD)指数和检出时间(DT),筛选出各模型的最优参数组合和最佳模型,应用201 1年猩红热报告病例数验证在最优参数组合下C1~C3模型的预警效果。结果表明,c1的最优参数组合为k=0.5,H=2c;C2的最优参数组合为k=0.7,H=20;C3的最优参数组合为矗=1.1,H=2a。在最优参数组合下,c1的YD指数为83.0%,DT平均值为0.64周;C2的YD指数为85.4%,DT平均值为1.27周;C3的YD指数为85.1%,DT平均值为1.36周。三种模型中C1的预警功效最好。c1一c3模型均在猩红热流行开始4周内发出预警信号。表明CUSUM模型在探测猩红热流行起始时间时具有较好的功效。 相似文献
5.
<正>2003年传染性非典型肺炎(SARS)和2009年甲型H1N1流感的全球暴发表明传染病依然是生命健康和社会经济的重大威胁。经济全球化、生产国际化、交通更加便捷、人货流动加快等因素的影响,使得传染病的传播速度加快、传播范围更广,也加大了传染病的防控难度。及早探测到传染病的早期暴发并发出预警和采取应对措施,对防止传染 相似文献
6.
[目的]评价在不同预警参数下,麻疹疫情自动预警系统的有效性;评价麻疹疫情自动预警系统的预警及时性情况;浅析系统实用性。[方法]以灵敏度、特异度等指标评价麻疹疫情自动预警系统的有效性;以预警信号数据信息的时间点间隔中位数评价麻疹疫情自动预警系统的及时性;对疾控中心人员就使用该系统的问题进行访谈,对系统实用性作定性评估。[结果]在所评价的时间段内,33个试点县(区)自动预警系统共发出麻疹预警信息2025次,试点地区对其中1条预警信号未作出响应;作了初步判断的2024条预警信息中,有2.87%信号与麻疹疑似流行有关;对预警信息的时间间隔分析表明,首例病人发病时间与预警时间的间隔为12d,预警时间与填报时间、现场调查完成时间的间隔均为0d;疑似病例48h完整调查率为89.7%;在P60、P70、P80和P90警戒限,麻疹的预警灵敏度均为100%,特异度大多在30%~70%之间。[结论]建立在病例实时直报的传染病监测系统基础上的传染病自动预警系统的及时性良好,试点地区麻疹预警的敏感性很高,特异度相对较低。根据目前的试点地区的效能分析结果,P90可能是较为合适的预警阈值。 相似文献
7.
症状监测在新发传染病和暴发疫情预警中应用的进展 总被引:4,自引:0,他引:4
近来,症状监测作为疾病监测的补充方法,以近于实时的速度对新发传染病和重大传染病暴发疫情进行预警,大大提高了疫情发现的敏感性和公共卫生预警能力,在国内外得到高度的重视和推广,在我国也取得很好的应用效果。笔者通过大量的国内外文献检索,描述了症状监测在新发传染病和暴发疫情预警中应用的进展及优势,并结合我国实际情况分析了目前症状监测在基层应用中存在推广应用成本昂贵、医疗机构缺乏信息平台、未能建立数字化的实时预警系统,以及需要建立多方位的公共数据交流平台等问题和困难。提出了在未来工作中需要结合实际情况适时推广症状监测,需立足现有条件,提高监测效率,并与传统的疾病监测系统和先进的实验室网络体系有机结合,迫切需要建立数字化信息系统来实现实时预警等策略建议。 相似文献
8.
目的 比较国家传染病自动预警系统(预警系统)中时间模型与时空模型在传染病暴发探测中的应用效果.方法 采用预警信号数、灵敏度、错误预警率和暴发探测时间等指标,分析比较2009年12月6日至2010年12月5日预警系统在20个省的221个试点县(区)采用时间模型和时空模型进行暴发探测的效果.结果 时间模型和时空模型灵敏度相同(均为98.15%),但时空模型较时间模型减少了59.86%(15 702条)的预警信号,时空模型的错误预警率(0.73%)低于时间模型(1.79%),时空模型的暴发探测时间(0d)也短于时间模型(1 d).结论 预警系统中的时空模型较时间模型具有更好的暴发探测效果.Abstract: Objective To analyze the pilot results of both temporal and temporal-spatial models in outbreaks detection in China Infectious Diseases Automated-alert and Response System (CIDARS)to further improve the system. Methods The amount of signal, sensitivity, false alarm rate and time to detection regarding these two models of CIDARS, were analyzed from December 6,2009 to December 5,2010 in 221 pilot counties of 20 provinces. Results The sensitivity of these two models was equal(both 98.15%). However, when comparing to the temporal model, the temporal-spatial model had a 59.86% reduction on the signals(15 702)while the false alarm rate of the temporal-spatial model(0.73%)was lower than the temporal model(1.79%), and the time to detection of the temporal-spatial model(0 day)was also 1 day shorter than the temporal model.Conclusion Comparing to the temporal model, the temporal-spatial model of CIDARS seemed to be better performed on outbreak detection. 相似文献
9.
目的 比较国家传染病自动预警系统(预警系统)中时间模型与时空模型在传染病暴发探测中的应用效果.方法 采用预警信号数、灵敏度、错误预警率和暴发探测时间等指标,分析比较2009年12月6日至2010年12月5日预警系统在20个省的221个试点县(区)采用时间模型和时空模型进行暴发探测的效果.结果 时间模型和时空模型灵敏度相同(均为98.15%),但时空模型较时间模型减少了59.86%(15 702条)的预警信号,时空模型的错误预警率(0.73%)低于时间模型(1.79%),时空模型的暴发探测时间(0d)也短于时间模型(1 d).结论 预警系统中的时空模型较时间模型具有更好的暴发探测效果. 相似文献
10.
目的 比较国家传染病自动预警系统(预警系统)中时间模型与时空模型在传染病暴发探测中的应用效果.方法 采用预警信号数、灵敏度、错误预警率和暴发探测时间等指标,分析比较2009年12月6日至2010年12月5日预警系统在20个省的221个试点县(区)采用时间模型和时空模型进行暴发探测的效果.结果 时间模型和时空模型灵敏度相同(均为98.15%),但时空模型较时间模型减少了59.86%(15 702条)的预警信号,时空模型的错误预警率(0.73%)低于时间模型(1.79%),时空模型的暴发探测时间(0d)也短于时间模型(1 d).结论 预警系统中的时空模型较时间模型具有更好的暴发探测效果. 相似文献
11.
CUSUM控制图法从工业及制造业质量控制领域引入医学领域以来,在公共卫生监测中的应用研究越来越广泛,特别是在异常信息监测预警及过程监测控制等方面国外开展较多,但在我国还未见相关研究报道.此文就国际上CUSUM控制图法在公共卫生监测中的应用研究进展进行了综述. 相似文献
12.
Response of finger circulation to energy equivalent combinations of magnitude and duration of vibration 总被引:4,自引:1,他引:3 下载免费PDF全文
OBJECTIVES—To investigate the acute response of finger circulation to vibration with different combinations of magnitude and duration but with the same "energy equivalent" acceleration magnitude according to current standards for hand transmitted vibration.
METHODS—Finger skin temperature (FST) and finger blood flow (FBF) were measured in the middle fingers of both hands of 10 healthy men who had not used hand held vibrating tools regularly. With a static load of 10 N, the right hand was exposed to 125 Hz vibration with the following unweighted root mean square (rms) acceleration magnitudes and durations of exposure: 44 m/s2 for 30 minutes; 62 m/s2 for 15 minutes; 88 m/s2 for 7.5 minutes; 125 m/s2 for 3.75 minutes; and 176 m/s2 for 1.88 minutes. These vibration exposures produce the same 8 hour energy equivalent frequency weighted acceleration magnitude (~1.4 m/s2 rms) according to international standard ISO 5349 (1986). Finger circulation was measured in both the right (vibrated) and the left (non-vibrated) middle fingers before application of the vibration, and at fixed intervals during exposure to vibration and during a 45 minute recovery period.
RESULTS—The FST did not change during exposure to vibration, whereas vibration with any combination of acceleration magnitude and duration produced significant percentage reductions in the FBF of the vibrated finger compared with the FBF before exposure (from −40.1% (95% confidence interval (95% CI) −24.3% to −57.2%) to −61.4% (95% CI −45.0% to −77.8%). The reduction in FBF during vibration was stronger in the vibrated finger than in the non-vibrated finger. Across the five experimental conditions, the various vibration stimuli caused a similar degree of vasoconstriction in the vibrated finger during exposure to vibration. There was a progressive decrease in the FBF of both fingers after the end of exposure to vibration with acceleration magnitudes of 44 m/s2 for 30 minutes and 62 m/s2 for 15 minutes. Significant vasoconstrictor after effects were not found in either finger after exposure to any of the other vibration stimuli with greater acceleration magnitudes for shorter durations.
CONCLUSIONS—For the range of vibration magnitudes investigated (44 to 176 m/s2 rms unweighted; 5.5 to 22 m/s2 rms when frequency weighted according to ISO 5349), the vasoconstriction during exposure to 125 Hz vibration was independent of vibration magnitude. The after effect of vibration was different for stimuli with the same energy equivalent acceleration, with greater effects after longer durations of exposure. The energy equivalent acceleration therefore failed to predict the acute effects of vibration both during and after exposure to vibration. Both central and local vasoregulatory mechanisms are likely to be involved in the response of finger circulation to acute exposures to 125 Hz vibration.
Keywords: finger circulation; energy equivalent acceleration magnitude; vibration frequency; magnitude; and duration 相似文献
METHODS—Finger skin temperature (FST) and finger blood flow (FBF) were measured in the middle fingers of both hands of 10 healthy men who had not used hand held vibrating tools regularly. With a static load of 10 N, the right hand was exposed to 125 Hz vibration with the following unweighted root mean square (rms) acceleration magnitudes and durations of exposure: 44 m/s2 for 30 minutes; 62 m/s2 for 15 minutes; 88 m/s2 for 7.5 minutes; 125 m/s2 for 3.75 minutes; and 176 m/s2 for 1.88 minutes. These vibration exposures produce the same 8 hour energy equivalent frequency weighted acceleration magnitude (~1.4 m/s2 rms) according to international standard ISO 5349 (1986). Finger circulation was measured in both the right (vibrated) and the left (non-vibrated) middle fingers before application of the vibration, and at fixed intervals during exposure to vibration and during a 45 minute recovery period.
RESULTS—The FST did not change during exposure to vibration, whereas vibration with any combination of acceleration magnitude and duration produced significant percentage reductions in the FBF of the vibrated finger compared with the FBF before exposure (from −40.1% (95% confidence interval (95% CI) −24.3% to −57.2%) to −61.4% (95% CI −45.0% to −77.8%). The reduction in FBF during vibration was stronger in the vibrated finger than in the non-vibrated finger. Across the five experimental conditions, the various vibration stimuli caused a similar degree of vasoconstriction in the vibrated finger during exposure to vibration. There was a progressive decrease in the FBF of both fingers after the end of exposure to vibration with acceleration magnitudes of 44 m/s2 for 30 minutes and 62 m/s2 for 15 minutes. Significant vasoconstrictor after effects were not found in either finger after exposure to any of the other vibration stimuli with greater acceleration magnitudes for shorter durations.
CONCLUSIONS—For the range of vibration magnitudes investigated (44 to 176 m/s2 rms unweighted; 5.5 to 22 m/s2 rms when frequency weighted according to ISO 5349), the vasoconstriction during exposure to 125 Hz vibration was independent of vibration magnitude. The after effect of vibration was different for stimuli with the same energy equivalent acceleration, with greater effects after longer durations of exposure. The energy equivalent acceleration therefore failed to predict the acute effects of vibration both during and after exposure to vibration. Both central and local vasoregulatory mechanisms are likely to be involved in the response of finger circulation to acute exposures to 125 Hz vibration.
Keywords: finger circulation; energy equivalent acceleration magnitude; vibration frequency; magnitude; and duration 相似文献
13.
14.
Luo J Sakakibara H Zhu SK Kondo T Toyoshima H 《International archives of occupational and environmental health》2000,73(4):281-284
In order to study the effect of the magnitude of vibrations and repetitive exposure on finger blood flow, we exposed ten
healthy subjects to three experimental conditions: (1) vibration of 3.16 m/s2 at 60 Hz, (2) vibration of 31.6 m/s2 at 60 Hz, and (3) no vibration, as a control. Under the experimental conditions, the right hand was exposed to 5-min vibration
three times, with intervening 5-min rests. Meanwhile, the blood flows of both middle fingers were continuously measured with
a blood flow meter based on the thermal diffusion method. Finger blood flow was significantly decreased in both hands with
exposure to vibrations of 3.16 m/s2 and 31.6 m/s2. Increased magnitude of vibration tended to enhance the decrease in finger blood flow in both hands, and repeated exposure
to vibration had cumulative effects on the decrease in finger blood flow in the unexposed left hand.
Received: 19 May 1999 / Accepted: 20 November 1999 相似文献
15.
目的 分析某餐馆诺如病毒暴发疫情中从业人员肠道排毒时间及其影响因素,为今后诺如病毒疫情的防控提供科学依据。方法 对2017年成都市某餐馆暴发诺如病毒疫情中的115名从业人员进行随访和采样检测,每隔3 d或7 d采集1次肛拭子进行核酸检测,对实验结果资料进行统计分析。结果 随访期餐馆从业人员第7、11、17、24天诺如病毒阳性率分别为14.78%、7.89%、3.51%、0.88%。阳性率呈现随时间推移而下降趋势,不同性别、工种间阳性率差异无统计学意义。从业人员感染率高达14.78%,其排毒期平均为14.94 d,最长28.00 d,且无症状携带者的排毒期较病例长。结论 诺如病毒暴发疫情中,食品从业人员存在无症状携带,其作为传染源在诺如病毒传播过程中所起的作用不容忽视,疫情处置中应加强从业人员的采样检测,对阳性检出者严格落实隔离措施。 相似文献
16.
17.
我国西部农村婴幼儿母乳喂养持续时间分析 总被引:1,自引:0,他引:1
目的了解我国西部农村婴幼儿母乳喂养持续时间的现状及其影响因素。方法采用横断面调查和分层多阶段随机抽样,运用COX回归模型分析。所有过程采用SPSS12.0软件包完成。结果西北、西南地区母乳喂养时间中位生存期分别为14、12个月。对于西北地区母乳喂养持续时间,小于4个月添加牛羊奶、外出打工、母亲在家、孩子出生顺序的RR值分别是1.290(1.096,1.518)、1.182(1.019,1.372)、0.694(0.586,0.822)、0.808(0.705,0.926)。对于西南地区母乳喂养持续时间,母亲在家、孩子出生顺序的RR值分别是0.756(0.631,0.906)、0.823(0.690,0.981)。结论农村经济发展的转型时期,父母外出打工是母乳喂养时间缩短的原因之一。另外,母乳喂养持续时间缩短还可能与母亲怀孕有关。 相似文献
18.
19.
目的系统介绍并探讨固定效应方差分析中四种离差平方和计算方法,为正确进行方差分析提供参考。方法介绍四种离差平方和的原理,结合实例展示具体计算过程和它们相互间的联系,并用SPSS和SAS软件验证。结果对相关理论和具体计算方面都给出了较详尽的过程。结论方差分析应根据数据特征选择离差平方和的计算方法。 相似文献
20.
三苯基铋的亚急性毒性和蓄积毒性及致突变作用 总被引:4,自引:0,他引:4
目的 研究三苯基铋(TPB)的亚急性毒性、蓄积毒性和致突变作用,为其在固体推进剂中的应用及防护提供毒理学依据。方法 毒性试验选用不同性别的昆明种小鼠44只,随机分为10.9,21.8,43.5mg/kg3个剂量组和1个对照组,小鼠隔日经口染毒35d。蓄积毒性试验选用不同性别的昆明种小鼠20只,随机分为2组,用固定剂量法染毒。致突变试验选用微核试验、精子畸形试验和Ames试验。结果毒性试验高剂量染毒组染毒1周时,小鼠出现活动减少,行动迟缓。肝脏器系数,中、高剂量染毒组(6.47%,8.63%)与对照组(5.01%)比较,差异有非常显著性(P<O.01);肾脏器系数,低、中剂量染毒组(1.26%,1.24%)与对照组(1.05%)比较,差异有显著性(P<O.05);各染毒组白细胞总数和血红蛋白含量与对照组比较,差异均无显著性(P>O.05);血清丙氨酸转氨酶(ALT)高剂量染毒组(122.70U)与对照组(53.38U)比较,差异有非常显著性(P<O.01)。血清尿素氮(BUN)各组间差异均无显著性(P>O.05)。病理学检查,中、高剂量染毒组肝细胞呈轻度水样变性,而低剂量染毒组改变不明显,其他脏器未见明显病理变化。TPB蓄积系数(K)为1.33,属于明显蓄积。致突变试验结果均为阴性。结论 TPB属中等毒性,具有明显蓄积作用,对肝细胞有明显的损伤作用,未见其具有致突变作用。 相似文献