北京市东城区公共场所冷却塔使用状况及健康风险评估

目的了解北京市东城区公共场所冷却塔使用及卫生状况,评估各场所冷却塔军团菌病健康风险。方法2018年5—9月,采集东城区内三类共26家公共场所冷却塔冷却水,填写相关调查问卷,通过冷却塔军团菌病健康风险指数模型计算各场所健康风险。结果本次研究中各场所冷却水样本嗜肺军团菌检测均为阴性,合格率为100%。游离性余氯平均为0.15 mg/L。酒店类场所冷却塔规模、加药方式和频率与其他场所有明显差别。26家公共场所健康综合风险平均为61.49,其中军团菌增殖风险、含菌气溶胶传播风险、暴露人群易感风险分别为16.13、22.66和22.70。不同场所冷却塔军团菌病健康风险评估结果存在一定差异,医院类场所健康风险指数高于酒店和商场(F=3.78,P<0.05)。结论冷却塔军团菌病健康风险高低主要受公共场所周围易感人群影响,该地区相关卫生部门应加强对相关易感人群的保护,对各类场所相关政策法规进行制定、完善和实施。     

环境镉污染健康风险评价指标体系的构建

目的 建立环境镉污染健康风险评价指标体系,为风险评估奠定基础,为风险管理提供理论依据.方法 采用德尔菲法和专家会议法相结合确定指标体系.结果 构建了包括3项一级指标、6项二级指标和20项三级指标的指标体系,并确定其权重值.结论 环境镉污染健康风险评价指标体系构建科学合理,指标体系的完善有待于进一步实证研究.     

深圳市公共场所集中空调冷却塔水嗜肺军团菌污染预警模型研究

摘要:目的　构建深圳市公共场所集中空调冷却塔水嗜肺军团菌污染预警模型,为预防控制军团菌病提供科学依据。方法　于2013年随机选择深圳市50家安装有集中空调的公共场所进行冷却塔卫生学调查,并进行现场相关指标检测,同时采集50份冷却水水样进行微生物指标、理化指标和嗜肺军团菌检测。结合文献报道及专家咨询利用卫生学调查、现场检测和实验室检测结果构建贝叶斯网络预警模型。于2014年随机选择30家公共场所集中空调冷却塔,并收集相关数据,利用2014年收集数据对预警模型进行验证和评价。结果　本研究构建的贝叶斯网络预警模型显示,对嗜肺军团菌最具有影响的因素有浊度、溶解性总固体、日照强度和防腐剂投放。该模型ROC曲线诊断临界点为0.338,利用该临界点进行嗜肺军团菌阳性诊断的灵敏度为100.0%,特异度为72.7%。结论　本研究所得的贝叶斯预警模型预测的灵敏度和特异度符合风险预警的要求,可以快速判断出冷却水嗜肺军团菌污染情况。     

公共场所中央空调系统冷却塔水及气溶胶军团菌污染的风险评估和预警研究

目的 构建中央空调系统冷却塔水及气溶胶军团菌污染的风险评估指标体系和风险预警模型.方法 于2008、2009年的5-9月采集马鞍山市16户宾馆、商场、公共浴室冷却塔水样70份,冷却塔气溶胶样品110份,分别进行军团菌分离培养和嗜肺军团菌mip基因的PCR检测.分析冷却塔水军团菌检出与气溶胶军团菌检出之间的关系,筛选可能...     

汕头口岸中央空调系统冷却塔军团菌污染现状及消毒效果评价

目的对汕头口岸中央空调系统军团菌污染现况进行监测,对采取的消毒措施进行初步的效果评价,为口岸卫生监督指导性。方法通过对汕头口岸中央空调系统冷却塔水采样开展军团菌检测;对污染的冷却塔水消毒处理后再次采样检测。结果从11份采集的冷却塔样本中检出嗜肺军团菌阳性标本5份,阳性率为45.45%;对污染的冷却塔采取消毒处理后,未检出军团菌。结论汕头口岸中央空调系统存在着军团菌污染,采取规范的消毒措施,可以降低军团菌病发生的风险。     

运用Delphi法建立健康促进幼儿园评价指标体系

目的采用Delphi专家咨询法建立健康促进幼儿园的评价指标体系。方法确定专家条件;遴择专家;初步拟定评价指标体系;分轮专家咨询;结果处理进行统计分析;确立评价指标体系。结果两轮函询的回收率分别为80%和70%。5项一级指标专家权威程度大于0.70,表明专家的权威程度较高。第二轮咨询5项一级指标的协调系数(包含一、二、三级指标)在0.154～0.356之间,第一轮咨询专家权威程度为0.186,第二轮为0.192,说明本次专家的意见有一定的协调性。综合专家的评分结果,结合专家权威系数,确定每项指标最终的组合权重。权重系数较大的一级指标是政策指标(0.2363)和社会环境指标(0.2623),其次是硬件指标(0.1843),社区关系指标(0.1456)和健康服务与健康技能指标(0.1715)权重较小。经过2轮专家函询确定的评价确定129项统计指标(一级指标5项,二级指标23项,三级指标101项)。结论综合考虑北京市城区幼儿园卫生工作的发展水平,本体系是一个全方位的评价指标体系,适用于对健康促进幼儿园工作的评价。     

基于Delphi法的电网员工职业健康风险评估指标体系的构建

目的应用Delphi法初步确定电网员工的职业健康风险评价指标体系,为筛选高风险亚人群和制定有针对性的防控措施提供科学依据。方法在文献分析及专家研讨会的基础上,构建“电网员工职业健康风险评价指标体系”雏形,在全省遴选19位职业健康风险评估专家,采用Delphi法进行2轮专家咨询,采用百分权重法计算一、二级指标的相对权重,建立评估指标体系。结果共对19名专家进行了2轮咨询,2轮咨询的专家积极系数均为100%,专家的权威系数平均为0.85。最终确立电网员工的职业健康风险评价指标体系包括5项一级指标和25项二级指标,5项一级指标分别为粉尘因素、物理因素、化学因素、行为因素和防护手段,权重系数分别为0.253 8、0.148 2、0.185 4、0.258 9、0.153 7。结论采用Delphi法初步建立的电网员工职业健康风险评估体系较为全面,可信度较高,可用于实证研究以进一步检验与完善。     

基于德尔菲法和层次分析法构建区域间居民健康素养综合评价指标体系的研究

目的 构建适合区域间可评价的居民健康素养指标体系，为各地区居民健康素养综合评价提供科学参考。方法 通过文献研究、政策评阅、小组讨论及半结构式访谈，初步建立居民健康素养综合评价指标体系的框架和指标池。选择15名公共卫生专家，运用德尔菲法进行两轮专家咨询确定各指标内容，第3轮应用层次分析法确定指标体系相应权重，最终构建出区域间居民健康素养综合评价指标体系。结果 经过3轮专家咨询，构建出一级指标5项，二级指标14项。一级指标按权重大小依次为政策倡导(0.2751)、法律保证(0.2635)、经济水平(0.1858)、社会支持(0.1680)、监测技术(0.1076);二级指标中权重前3位分别为健康促进相关条例(0.1683)、本地区健康细胞工程建设普及率及成效(0.1260)、城市医疗卫生总支出占(GDP)的百分比(0.1147)。层次分析判断矩阵的一致性比率均小于0.1000,结果可信度较高。结论 本研究运用德尔菲法和层次分析法构建了适用于区域间比较的居民健康素养综合评价指标体系，结果显示具有较高的科学性及可操作性，为下一步应用及推广奠定基础。     

采用Delphi法筛选城市居民健康生活方式评价指标体系

目的研究建立城市居民健康生活方式评价指标系统,为促进健康生活方式的形成提供标准化的群体监测工具,以便对实际健康教育工作进行有效的评价和推进。方法首先通过专家座谈会初步确定指标体系一二级维度,之后采用Delphi法进行指标重要性评判和筛选,构建健康生活方式评价指标体系,并通过现场调查对指标体系进行验证。结果2轮Delphi法咨询问卷回收率均高于85%,专家权威程度分别为0.88、0.86;通过第二轮Delphi法筛选出符合要求的三级评价指标54项,分别评价健康生活方式的5个部分:营养膳食、身体活动、心理健康、生活行为和健康责任;得到初步指标体系。结论利用Delphi法建立的健康生活方式评价指标体系具有较强的可操作性和较大的实用价值。     

产科护士健康教育能力评价指标体系的构建

目的构建一套客观、科学的产科护士健康教育能力评价指标体系,为评价产科护士健康教育能力提供依据。方法采用德尔菲法和层次分析法建立产科护士健康教育能力评价指标体系并分析各级指标权重。结果通过对15名专家的3轮函询构建了包含3项一级指标,11项二级指标,32项三级指标的指标体系。结论初步建立了产科护士健康教育能力评价指标体系,构建过程较科学,但需在实践中进一步验证。     

A model for autumn outbreaks of Legionnaires' disease associated with cooling towers, linked to system operation and size.

Cooling towers have been demonstrated to be amplifiers and disseminators of legionella, the causative organism of Legionnaires'' disease. Community outbreaks associated with cooling towers have been reported with several common factors. Small towers (< 300 kW) have predominantly been implicated in outbreaks. Cooling tower-associated outbreaks are most frequent in autumn, and frequently implicated systems have been operated after a period of shutdown. This paper reports field study data relating system operation to legionella colonization of systems. Operating systems have been shown to be more frequently colonized by legionella than shutdown systems. In some cases operation of systems after periods of shutdown raised legionella concentrations from below detection limits to between 50 and 950 c.f.u./ml within 10 min. These data and previously reported data relating to biofilm and sediment colonization of the systems, and community outbreaks of Legionnaires'' disease, have been used to develop a model explaining the seasonal nature of outbreaks associated with irregularly operated, small cooling tower systems.     

Assessing the environmental health relevance of cooling towers – A systematic review of legionellosis outbreaks

Bioaerosols from cooling towers are often suspected to cause community-acquired legionellosis outbreaks. Although Legionella infections can mostly be assigned to the emission sources, uncertainty exists about the release and distribution into the air, the occurrence of the respirable virulent form and the level of the infective concentration. Our study aimed to evaluate studies on legionellosis outbreaks attributed to cooling towers published within the last 11 years by means of a systematic review of the literature. 19 legionellosis outbreaks were identified affecting 12 countries. Recurring events were observed in Spain and Great Britain. In total, 1609 confirmed cases of legionellosis and a case-fatality rate of approximately 6% were reported. Duration of outbreaks was 65 days on average. For diagnosis the urinary antigen test was mainly used. Age, smoking, male sex and underlying diseases (diabetes, immunodeficiency) could be confirmed as risk factors. Smoking and underlying diseases were the most frequent risk factors associated with legionellosis in 11 and 10 of the 19 studies, respectively. The meteorological conditions varied strongly. Several studies reported a temporal association of outbreaks with inadequate maintenance of the cooling systems. A match of clinical and environmental isolates by serotyping and/or molecular subtyping could be confirmed in 84% of outbreaks. Legionella-contaminated cooling towers as environmental trigger, in particular in the neighbourhood of susceptible individuals, can cause severe health problems and even death. To prevent and control Legionella contamination of cooling towers, maintenance actions should focus on low-emission cleaning procedures of cooling towers combined with control measurements of water and air samples. Procedures allowing rapid detection and risk assessment in the case of outbreaks are essential for adequate public health measures. Systematic registration of cooling towers will facilitate the identification of the source of outbreaks and help to shorten their duration.     

Fatal nosocomial Legionnaires' disease: relevance of contamination of hospital water supply by temperature-dependent buoyancy-driven flow from spur pipes.

The investigation, epidemiology, and effectiveness of control procedures during an outbreak of Legionnaires'' disease involving three immunosuppressed patients are described. The source of infection appeared to be a network of fire hydrant spurs connected directly to the incoming hospital mains water supply. Removal of these hydrants considerably reduced, but failed to eliminate, contamination of water storage facilities. As an emergency control procedure the incoming mains water was chlorinated continuously. Additional modifications to improve temperature regulation and reduce stagnation also failed to eliminate the legionellae. A perspex test-rig was constructed to model the pre-existing hospital water supply and storage system. This showed that through the hydraulic mechanism known as ''temperature buoyancy'', contaminated water could be efficiently and quickly exchanged between a stagnant spur pipe and its mains supply. Contamination of hospital storage tanks from such sources has not previously been considered a risk factor for Legionnaires'' disease. We recommend that hospital water storage tanks are supplied by a dedicated mains pipe without spurs.     

深圳市南山区公共场所集中空调冷却塔卫生管理状况

目的了解深圳市南山区公共场所集中空调冷却塔的卫生管理状况,探索卫生监督管理对策。方法采用问卷调查和询问相结合的方式,于2013年对南山区40家公共场所集中空调冷却塔设计、管理和使用情况进行调查分析。结果南山区公共场所均无集中空调冷却塔制定预防空气传播性疾病应急预案;冷却塔管理人员对相关法规知晓率和接受相关培训率分别为55.0%、5.0%;所有冷却塔均进行了定期清洗和消毒,消毒方式主要是投放消毒剂;97.5%的公共场所都定期进行了冷却水水质检测。结论南山区公共场所集中式空调冷却塔的卫生管理状况较差,卫生行政部门应加大集中空调冷却塔的预防性卫生监督审查的力度,使用单位应进行整改并建立健全卫生管理制度,保障人民群众的身体健康。     

Phenotypic variation amongst genotypically homogeneous Legionella pneumophila serogroup 1 isolates: implications for the investigation of outbreaks of Legionnaires' disease.

One hundred and seventy-nine isolates of Legionella pneumophila serogroup 1, obtained from a site associated with an outbreak of Legionnaires'' disease, were examined by monoclonal antibody subgrouping, restriction fragment length polymorphism typing, restriction endonuclease analysis and plasmid content. Nine distinct phenotypes were detected but at the genotypic level all strains were closely related. The data presented indicate that phenotypic variation of a single parent strain can occur within an environmental site. The implications of these findings are discussed in relation to the investigation of outbreaks of Legionnaires'' disease.     

Potable water and nosocomial Legionnaires' disease--check water from all rooms in which patient has stayed.

We studied 7 patients with nosocomial Legionnaires'' disease to determine the relationship between isolates of Legionella pneumophila recovered from potable water and those recovered from patients. Potable water was cultured from all rooms in which patients had stayed prior to the diagnosis of Legionnaires'' disease. The 38 isolates of L. pneumophila (31 environmental, 7 patient) were resolved into 9 distinct patterns by pulse-field gel electrophoresis (PFGE), 3 by plasmid content and 2 each with monoclonal antibodies and conventional agarose gel electrophoresis of small fragments of DNA. Using PFGE it was determined that 4 of the 7 patients were infected with L. pneumophila identical to an isolate recovered from the potable water supply in one of the rooms each had occupied prior to the diagnosis of Legionnaires'' disease. Patients had resided in a mean of 3.57 rooms before a diagnosis of nosocomial Legionnaires'' disease. We conclude that in the setting of contaminated potable water and nosocomial Legionnaires'' disease water from all the rooms which the patient has occupied prior to this diagnosis should be cultured. PFGE of large DNA fragments discriminated best among the isolates of L. pneumophila.     

Decreasing trend of Legionella isolation in a long-term microbial monitoring program in Greek hospitals

Legionnaires' disease is a known cause of severe pneumonia in a nosocomial setting. This study examined Legionella isolation in Greek hospitals. Water samples and swabs of showerheads from 41 hospitals were collected over a four-year period (2004-2007) from hot and cold water systems and cooling towers in Greece. In total, 1058 samples were examined for the presence of Legionella. From the hot water samples examined, 166 out of 607 (27.3%) were positive for Legionella, including 111 (18.3%) positive for Legionella pneumophila sg1 samples. The temperature of hot water samples less than 55°C was statistically significant, associated with Legionella spp. isolation (RR 4.01, 95%CI 2.33-6.92). Ten out of 17 (58.8%) hospital cooling towers required remedial actions due to Legionella colonization. Reemergence of Legionella spp. colonization was evident in more than half of the hospitals where frequent monitoring and appropriate risk assessment plans were absent or lacking. Hospitals that were monitored continuously over the study period presented a decreasing trend of Legionella colonization. Environmental risk assessment together with Legionella isolation should be enforced systematically in hospitals.     

Outbreak of Legionnaires' disease at University Hospital, Nottingham. Epidemiology, microbiology and control.

Twelve patients in a large teaching hospital contracted Legionnaires'' disease over a period of 11 months. The source was a domestic hot water system in one of the hospital blocks, which was run at a temperature of 43 degrees C. Five different subtypes of Legionella pneumophila serogroup 1 have been isolated from water in different parts of the hospital, over a period of time. Only one subtype, Benidorm RFLP 14, was implicated in disease. Circumstantial evidence suggested that the outbreak may have been due to recent colonization of the hot water system with a virulent strain of Legionella pneumophila. The outbreak was controlled by raising the hot water temperature to 60 degrees C, but careful surveillance uncovered two further cases in the following 30 months. Persistent low numbers of Legionella pneumophila were isolated from the domestic hot water of wards where Legionnaires'' disease had been contracted, until an electrolytic unit was installed releasing silver and copper ions into this supply.     

Strengths and limitations of molecular subtyping in a community outbreak of Legionnaires' disease

An epidemiological and microbiological investigation of a cluster of eight cases of Legionnaires' disease in Los Angeles County in November 1997 yielded conflicting results. The epidemiological part of the investigation implicated one of several mobile cooling towers used by a film studio in the centre of the outbreak area. However, water sampled from these cooling towers contained L. pneumophila serogroup 1 of another subtype than the strain that was recovered from case-patients in the outbreak. Samples from two cooling towers located downwind from all of the case-patients contained a Legionella strain that was indistinguishable from the outbreak strain by four subtyping techniques (AP-PCR, PFGE, MAb, and MLEE). It is unlikely that these cooling towers were the source of infection for all the case-patients, and they were not associated with risk of disease in the case-control study. The outbreak strain also was not distinguishable, by three subtyping techniques (AP-PCR, PFGE, and MAb), from a L. pneumophila strain that had caused an outbreak in Providence, RI, in 1993. Laboratory cross-contamination was unlikely because the initial subtyping was done in different laboratories. In this investigation, microbiology was helpful for distinguishing the outbreak cluster from unrelated cases of Legionnaires' disease occurring elsewhere. However, multiple subtyping techniques failed to distinguish environmental sources that were probably not associated with the outbreak. Persons investigating Legionnaires' disease outbreaks should be aware that microbiological subtyping does not always identify a source with absolute certainty.