北京市SARS隔离医学观察效果评价

目的 了解北京市严重急性呼吸综合征(SARS)流行期间被隔离医学观察人群的构成及发病情况，为科学合理地隔离SARS病例的接触者提供依据。方法 把海淀区按地理方位分为东、西、南、北、中5个区域，每个区域从有隔离观察人群的街道(乡镇)中抽取1个街道(乡镇)，通过街道(乡镇)“非典”防治办公室，布置有被隔离医学观察对象的居委会把统一的调查表发给被隔离观察者，让其自己填写调查表。若无法自己填写，则请他人代为填写。结果 共调查被隔离者1028名，发现24例SARS病例，罹患率2．3％；61％(630／1028)的人是因为接触SARS病例而被隔离的，其中61％(383／630)的人在SARS病例的症状期与其接触；24例病例均在SARS病例的症状期与其接触；未在SARS病例症状期与其接触的人均未发病，这部分人占被隔离人数的63％(645／1028)；167名在SARS病例潜伏期与其接触的人均未发病。结论 只有在SARS病例发病后与其接触的人员才需要隔离，如果以此标准对SARS的直接接触者进行隔离，则可以节省63％的费用。未发现SARS病例在潜伏期有传染性。     

Quarantine for SARS, Taiwan

During the 2003 outbreak of severe acute respiratory syndrome (SARS) in Taiwan, >150,000 persons were quarantined, 24 of whom were later found to have laboratory-confirmed SARS-coronavirus (SARS-CoV) infection. Since no evidence exists that SARS-CoV is infective before the onset of symptoms and the quarantined persons were exposed but not symptomatic, we thought the quarantine's effectiveness should be investigated. Using the Taiwan quarantine data, we found that the onset-to-diagnosis time of previously quarantined confirmed case-patients was significantly shortened compared to that for those who had not been quarantined. Thus, quarantine for SARS in Taiwan screened potentially infective persons for swift diagnosis and hospitalization after onset, thereby indirectly reducing infections. Full-scale quarantine measures implemented on April 28 led to a significant improvement in onset-to-diagnosis time of all SARS patients, regardless of previous quarantine status. We discuss the temporal effects of quarantine measures and other interventions on detection and isolation as well as the potential usefulness of quarantine in faster identification of persons with SARS and in improving isolation measures.     

Use of quarantine to prevent transmission of severe acute respiratory syndrome--Taiwan, 2003

On July 5, 2003, Taiwan was removed from the World Health Organization (WHO) list of severe acute respiratory syndrome (SARS)-affected countries. As of July 9, a total of 671 probable cases of SARS had been reported in Taiwan. On February 21, the first identified SARS patient in Taiwan returned from travel to Guangdong Province, mainland China, by way of Hong Kong. Initial efforts to control SARS appeared to be effective; these efforts included isolation of suspect and probable SARS patients, use of personal protective equipment (PPE) for health-care workers (HCWs) and visitors, and quarantine of contacts of known SARS patients. However, beginning in mid-April, unrecognized cases of SARS led to a large nosocomial cluster and subsequent SARS-associated coronavirus transmission to other health-care facilities and community settings. In response to the growing epidemic, additional measures were taken to limit nosocomial and community transmission of SARS, including more widespread use of quarantine. By the end of the epidemic, 131,132 persons had been placed in quarantine, including 50,319 close contacts of SARS patients and 80,813 travelers from WHO-designated SARS-affected areas. This report describes the quarantine measures used in Taiwan and discusses the need for further evaluation of quarantine and other control measures used to prevent SARS.     

北京市海淀区403例传染性非典型肺炎的流行病学分析

目的　分析北京市海淀区常住人口传染性非典型肺炎 [严重急性呼吸综合征 (SARS) ]的流行病学特征。方法　对海淀区常住人口中发生的SARS病例进行个案调查和描述性分析。结果2 0 0 3年 3月 1 8日至 5月 31日 ,海淀区常住人口中共发生SARS病例 40 3例 ,发病率约为 1 8.0 1 0万 ,死亡 2 7例 ,病死率为 6 .7%。患者中青壮年占 70 .4% ,尤以 2 0～ 2 9岁组高发。全区除一个乡外均受累 ,多以散发为主 ,只有 3个街道呈现明显的家庭或学校内爆发。流行基本可以划分为初始增长期(2 7天 )、高峰期 (2 1天 )和快速下降期 (2 6天 )。患者中有密切接触史的比例随各期呈递减趋势 (趋势χ2 =8.80 0 ,P =0 .0 0 3) ;初期接触地点主要在医院 (72 .7% ) ,而迅速下降期则以家中接触为主(85 .7% ) ;各期的职业构成谱也明显不同 (χ2 =36 .41 ,P <0 .0 1 )。无明确接触史的患者中 2 6 .6 %有外出史 ,其中又有 47.6 %是去医院 ,并且 65 %在流行的高峰期光顾医院。结论　海淀区常住人口SARS流行强度与全市持平 ,医院内获得感染是SARS流行的主要原因     

Dynamically modeling SARS and other newly emerging respiratory illnesses: past, present, and future

The emergence and rapid global spread of the severe acute respiratory syndrome (SARS) coronavirus in 2002-2003 prompted efforts by modelers to characterize SARS epidemiology and inform control policies. We overview and discuss models for emerging infectious diseases (EIDs), provide a critical survey of SARS modeling literature, and discuss promising future directions for research. We reconcile discrepancies between published estimates of the basic reproductive number R0 for SARS (a crucial epidemiologic parameter), discuss insights regarding SARS control measures that have emerged uniquely from a modeling approach, and argue that high priorities for future modeling of SARS and similar respiratory EIDs should include informing quarantine policy and better understanding the impact of population heterogeneity on transmission patterns.     

SARS control and psychological effects of quarantine, Toronto, Canada

As a transmissible infectious disease, severe acute respiratory syndrome (SARS) was successfully contained globally by instituting widespread quarantine measures. Although these measures were successful in terminating the outbreak in all areas of the world, the adverse effects of quarantine have not previously been determined in a systematic manner. In this hypothesis-generating study supported by a convenience sample drawn in close temporal proximity to the period of quarantine, we examined the psychological effects of quarantine on persons in Toronto, Canada. The 129 quarantined persons who responded to a Web-based survey exhibited a high prevalence of psychological distress. Symptoms of posttraumatic stress disorder (PTSD) and depression were observed in 28.9% and 31.2% of respondents, respectively. Longer durations of quarantine were associated with an increased prevalence of PTSD symptoms. Acquaintance with or direct exposure to someone with a diagnosis of SARS was also associated with PTSD and depressive symptoms.     

国境口岸传染性非典型肺炎检疫措施的研究

目的促进国境口岸防制传染性非典型肺炎(SARS)检疫措施的完善。方法对我国国境口岸SARS检疫措施进行调查研究,收集国内外防制SARS检疫措施的资料,并进行比较。结果在SARS流行期间,世界上大部分国家针对境内的国际机场、港口等出入境口岸,采取了不同的检疫措施,多数采取的是入境口岸检查和填写登记卡。我国在国境口岸实施对出入境人员现场医学观察、检疫检查和要求填写《出(入)境健康申明卡》的检疫措施,有效地防止了SARS的传入传出,但同时也给出入境人员造成了一些麻烦和精神上的负担,不利于检疫措施的实施。包括：修改《出(入)境健康申明卡》,使其内容更简单、科学、有针对性,字更通俗;改进体温测量及处理的操作规程,设立一套科学的口岸检疫应对危机管理机制,对发热病人带来疫病的可能性进行风险评估,分级后采取相应措施。结论借鉴某些国家防制SARS的经验,通过调整和完善检疫措施,防止SARS的传入和传出。     

Understanding, compliance and psychological impact of the SARS quarantine experience

This study examines a cohort of persons quarantined during the 2003 SARS outbreak in Canada and describes their understanding of, difficulties and compliance with, and the psychological impact of the quarantine experience. A mailed questionnaire was administered to 1912 eligible adults and included the Impact of Events Scale - Revised (IES-R) to assess symptoms of post-traumatic stress disorder (PTSD). Self-reported compliance with all required quarantine measures was low (15.8+/-2.3%), although significantly higher when the rationale for quarantine was understood (P=0.018). Health-care workers (HCW) experienced greater psychological distress, including symptoms of PTSD (P<0.001). Increasing perceived difficulty with compliance, HCW, longer quarantine and compliance with quarantine requirements were significant contributors to higher IES-R scores. The low compliance with quarantine requirements introduces concerns about the effectiveness of quarantine as a public health measure. Improvements in compliance and reduced psychological distress may be possible by minimizing duration, revising requirements, and providing enhanced education and support.     

How did general practitioners protect themselves, their family, and staff during the SARS epidemic in Hong Kong?

CONTEXT: Severe acute respiratory syndrome (SARS) is a newly emerging infectious disease and how the frontline community doctors respond to it is not known. OBJECTIVES: To explore the impact of SARS on general practitioners (GPs) in Hong Kong. DESIGN: A cross sectional survey. SETTING: Community based primary care clinics. PARTICIPANTS: 183 family medicine tutors affiliated with a local university. Postal survey sent to all tutors with a 74.8% response rate. MAIN OUTCOME MEASURES: Change of clinical behaviour and practices during the epidemic; anxiety level of primary care doctors. RESULTS: All agreed SARS had changed their clinical practices. Significant anxiety was found in family doctors. Three quarters of respondents recalled requesting more investigations while a quarter believed they had over-prescribed antibiotics. GPs who were exposed to SARS or who had worked in high infection districts were less likely to quarantine themselves (10.8% versus 33.3%; p<0.01; 6.5% versus 27.5%; p<0.01 respectively). Exposure to SARS, the infection rates in their working district, and anxiety levels had significant impact on the level of protection or prescribing behaviour. CONCLUSION: The clinical practice of GPs changed significantly as a result of SARS. Yet, those did not quarantine themselves suggesting other factors may have some part to play. As failure to apply isolation precautions to suspected cases of SARS was one major reason for its spread, a contingency plan from the government to support family doctors is of utmost importance. Interface between private and public sectors are needed in Hong Kong to prepare for any future epidemics.     

Severe acute respiratory syndrome, Beijing, 2003

The largest outbreak of severe acute respiratory syndrome (SARS) struck Beijing in spring 2003. Multiple importations of SARS to Beijing initiated transmission in several healthcare facilities. Beijing's outbreak began March 5; by late April, daily hospital admissions for SARS exceeded 100 for several days; 2,521 cases of probable SARS occurred. Attack rates were highest in those 20-39 years of age; 1% of cases occurred in children <10 years. The case-fatality rate was highest among patients >65 years (27.7% vs. 4.8% for those 20-64 years, p < 0.001). Healthcare workers accounted for 16% of probable cases. The proportion of case-patients without known contact to a SARS patient increased significantly in May. Implementation of early detection, isolation, contact tracing, quarantine, triage of case-patients to designated SARS hospitals, and community mobilization ended the outbreak.     

崇文区居民传染性非典型肺炎防治信息和媒体材料的需求评估

目的评估居民对传染性非典型肺炎(简称"非典")防治信息和媒体材料的需求状况,指导今后健康教育传播材料的制作.方法采用二阶段分层随机抽样的方法抽取北京市崇文区18～60岁的本市居民274名和流动人员244名,并对他们进行问卷调查.结果本市居民和流动人员对大部分"非典"预防基本知识的知晓率较高,均在70%以上,但对传染病预防控制法律法规和"非典"治疗知识的知晓率相对较低.在媒体需求方面,本市居民更希望得到声像类宣传品,而流动人员更倾向于图画为主、图文并茂的宣传资料,两者之间存在统计学差异(P<0.01).结论在"非典"流行的特殊时期,健康教育宣传工作发挥了不可替代的重要作用,但应针对不同人群、不同需求采用不同的宣传方式才能达到预期效果;同时要关注公众的心理问题,并主动向公众宣传公共政策和相关法律法规等内容.     

传染性非典型肺炎分布特征及报告质量分析

目的 :分析传染性非典型肺炎 (SARS)分布特征 ,评价疫情报告质量 ,为今后制定对策提供依据。方法 :收集全国内地 SARS疫情及相关资料 ,采用统计学软件进行分析。结果 :医务人员发病率是其他人群的 5 6 .5 8倍 ;流行期间从事 SARS诊治的医务人员发病概率为 0 .5 36 /10 0人天 ,采取综合措施后下降至 0 .0 4 2 /10 0人天以下 ;6个流行强度较大的省市医务人员发病构成比明显高于其它省市 ;首发病例与北京有关省市的病死率明显高于与广东有关的省市 ;除北京外全国内地其它地区疑似病例漏报严重。结论 :医务人员的发病水平对当地 SARS流行强度影响较大 ;建议修订诊断标准和使用监测系统敏感性评价指标     

Primary care physicians in Hong Kong and Canada--how did their practices differ during the SARS epidemic?

BACKGROUND: Hong Kong and Canada have very different primary health care systems. We thus hypothesized family physicians between the two places would be different in how they protected themselves, their staff and families during the epidemic. OBJECTIVE: The purpose of this study was to explore and contrast the impact of SARS on family physicians in Hong Kong and Toronto. METHODS: A postal questionnaire was designed and sent to 183 tutors affiliated with the Chinese University of Hong Kong with 137 replies (74.8%). In Toronto, 150 questionnaires were sent to academic family physicians affiliated with the University of Toronto with 51 replies (34%). RESULTS: All agreed SARS had changed their clinical behaviour. For public health measures in the control of SARS, Hong Kong physicians were less likely to quarantined themselves (77.1% versus 19.4%, P < 0.01) or gave quarantine leave to staff (95% versus 59.7%, P < 0.01) after exposure to probable or suspected SARS. However, they were more likely to wear a mask (52.7% versus 97.7%, P = 0) during consultation, having support staff to wear masks (68.6% versus 97.8%, P = 0) and test patient's temperature (47.1% versus 68.1%, P < 0.01). CONCLUSION: There were noticeable differences in how family physicians deal with SARS between the two cities. As SARS emerged as a global disease, better understanding of practice differences among physicians from different countries would facilitate globalization of public health.     

应用系统动力学模型对SARS疫情传播及主要防控措施效果的计算机模拟仿真研究

目的　(1)应用系统动力学方法建立数学模型,宏观地模拟严重急性呼吸综合征(SARS)疫情在自然人群和医院内传播的过程,以及患者通过就诊和社区隔离措施移出传播链的过程。(2)通过计算机对该模型的仿真模拟,分析在突发 SARS疫情的情况下,代表主要防控措施的变量对疫情曲线的影响模式和相对强度。(3)重点分析发热监测措施对疫情的影响,根据分析结果对今后SARS防控工作提出政策建议。方法　采用面访、问卷调查、文献检索、个案分析等方式,获取SARS传播的重要参数。应用系统动力学理论及计算机仿真系统建立数学模型,并进行 What if仿真分析。结果　建立了能够反映SARS自然传播、患者就诊及医院内传播、社区隔离措施、发热监测过程的计算机仿真模型,通过宏观模拟SARS患者从发病到被移出传播链的过程得出下列结果:(1)患者从发病到就诊的时间、患者每日平均接触人数、就诊时医院内接触人数等是对 SARS的院内、院外传播过程影响最大的几个变量;(2)隔离强度、接诊医生对 SARS的警惕性、医院通风消毒、医院优化患者流动路线、医生防护强度是影响疫情控制的主要变量;(3)医院入口的体温筛查措施对疫情控制的作用不大。结论　按照目前制定的SARS防治预案,卫生系统能够快速控制突发的SARS疫情。     

Understanding the spatial diffusion process of severe acute respiratory syndrome in Beijing

OBJECTIVES: To measure the spatial contagion of severe acute respiratory syndrome (SARS) in Beijing and to test the different epidemic factors of the spread of SARS in different periods. METHODS: A join-count spatial statistic study was conducted and the given hypothetical processes of the spread of SARS in Beijing were tested using various definitions of 'joins'. RESULTS: The spatial statistics showed that of the six diffusion processes, the highest negative autocorrelation occurred in the doctor-number model (M-5) and the lowest negative autocorrelation was found in the population-amount model (M-3). The results also showed that in the whole 29-day research period, about hour or more days experienced a significant degree of contagion. CONCLUSIONS: Spatial analysis is helpful in understanding the spatial diffusion process of an epidemic. The geographical relationships were important during the early phase of the SARS epidemic in Beijing. The statistic based on the number of doctors was significant and more informative than that of the number of hospitals. It reveals that doctors were important in the spread of SARS in Beijing, and hospitals were not as important as doctors in the contagion period. People are the key to the spread of SARS, but the population density was more significant than the population size, although they were both important throughout the whole period.     

Spatial dynamics of an epidemic of severe acute respiratory syndrome in an urban area

OBJECTIVE: To map risk of exposure to severe acute respiratory syndrome (SARS) in an urban area and assess the ability of traditional interventions to control dispersion of the disease. METHODS: Data on the Beijing SARS epidemic were used to map spatial clusters of identified contacts and to estimate transmission of SARS using a model with a time-dependent transmission rate. RESULTS: The estimated transmission rate decreased dramatically from 20 to 30 April 2003. The total number of cases in the epidemic in Beijing was estimated to be 2521. Hierarchical clustering revealed that risk-exposures were widespread, but clustered in a pattern that is distinctly related to the Beijing urban ring roads. CONCLUSION: Traditional control measures can be very effective at reducing transmission of SARS. Spatial patterns of risk-exposures can inform disease surveillance, prediction and control by identifying spatial target areas on which interventions should be focused.     

SARS related preventive and risk behaviours practised by Hong Kong-mainland China cross border travellers during the outbreak of the SARS epidemic in Hong Kong

OBJECTIVES: To investigate patterns of behaviours and attitudes related to SARS prevention in the Hong Kong cross border traveller population.Settings: A survey was carried out at the Hong Kong-China cross border checkpoint in the middle of the epidemic. PARTICIPANTS: A total of 839 Hong Kong adult residents returning to Hong Kong from mainland China were surveyed. MAIN OUTCOME MEASURES: Practice of preventive measures and relevant behaviours and attitudes. RESULTS: Around 40% of the respondents were using masks all or most of the time in public places or washing their hands frequently (>10 times per day) and about one third avoided visiting crowded places in mainland China. Such figures were however lower than those practised by the general public in Hong Kong. SARS related perceptions, such as perceived risk of transmission and efficacy, etc, were associated with mask use and not visiting crowded places, but not with hand washing, which was associated with duration of stay. Gender differences were also observed. Around 70% of the travellers would have delayed medical consultation for influenza-like illness in China; 12.7% would not wear masks during such episodes of illness. Furthermore, about 30% of the respondents used to wear masks in Hong Kong but not in mainland China. CONCLUSIONS: The findings have implications on cross border prevention of SARS. It seems that those travelling during the SARS epidemic were a "self selected" group, and they were using less preventive measures. Special attention and intervention need to be provided to travellers to prevent a second wave cross border transmission of the disease.     

北京市2003年SARS疫情的多维分布及其影响因素分析

目的采用多维可视化分析研究北京市2003年严重急性呼吸综合征(SARS)疫情的扩散过程。方法以北京市SARS疫情数据,结合北京市地理信息系统,基于数据驱动和模型驱动的理论和技术,利用热点分析、空间过程分析和因子识别等数据探索分析方法,根据传染病的多维传播特性,同时利用遗传规划和模拟退火相结合的算法对易感-感染-移出(SIR)模型求解,从模型直接求取SARS流行病学参数。结果SARS密切接触者在城市内部呈现出大尺度上沿交通线聚集和在小尺度上随机分布态势;在不同发展阶段,北京市SARS发病趋势存在显著的空间聚集和扩散变化特征;地理位置、人口以及医院和医生数量是SARS空间传播的重要影响因子;通过对SIR模型直接求解,反演传染病参数,对SARS确诊病例数可进行早期预报性分析。结论对SARS密切接触者的集聚探测揭示了北京市人群存在两个空间尺度上的流动接触过程,为人-人接触性传染病的预防和控制策略制定提供重要依据;多个环境和人文因子对SARS传播起作用,其统计显著性随时间变化;有效的算法可以对SIR直接求解,使其可以用于传染病参数反演和早期预测。     

Modelling potential responses to severe acute respiratory syndrome in Japan: the role of initial attack size, precaution, and quarantine

BACKGROUND: There has been an outbreak of the severe acute respiratory syndrome (SARS) worldwide. With the use of detailed epidemiological data from other countries, this article describes the possible reason for the SARS epidemic not appearing in Japan, and simulates the impact of different control strategies that can break the transmission cycle of SARS associated coronavirus. METHOD: Mathematical modelling is used for predicting the epidemiological outcome and simultaneously for evaluating the effect of interventions on SARS. The study estimates the initial attack size that would result in failed invasion. Three different interventions have been incorporated into the public health response policies; precautionary public health measures, isolation of infected people, and quarantine of exposed humans. RESULTS: The maximum number of humans newly infected could be roughly estimated on the basis of the initial attack size, using simple formulas. It is seen that the introduction of only a few cases into certain communities would not lead easily to an epidemic. The possible trajectories of SARS epidemic depend on the levels of public health interventions as quarantine and precautionary public health measures greatly affected the transmissibility of the disease. It is shown that there exist threshold levels of interventions at which the SARS epidemic settles down. CONCLUSION: Initial attack size is one of the determinants of whether SARS can successfully invade the community or not. Two of the most effective policy procedures to prevent new infections would be to apply stringent precautionary measures and to impose quicker and more effective quarantine of the exposed populace.