An initial investigation of the association between the SARS outbreak and weather: with the view of the environmental temperature and its variation

OBJECTIVE: To understand the association between the SARS outbreak and the environmental temperature, and to provide a scientific basis for prevention and control measures against it. METHODS: The daily numbers of the probable SARS patients and the daily meteorological factors during the SARS outbreak period in Hong Kong, Guangzhou, Beijing, and Taiyuan were used in the data analysis. Ecological analysis was conducted to explore the association between the daily numbers of probable SARS patients and the environmental temperature and its variations. RESULTS: There was a significant correlation between the SARS cases and the environmental temperature seven days before the onset and the seven day time lag corresponds well with the known incubation period for SARS. The optimum environmental temperature associated with the SARS cases was between 16 degrees C to 28 degrees C, which may encourage virus growth. A sharp rise or decrease in the environmental temperature related to the cold spell led to an increase of the SARS cases because of the possible influence of the weather on the human immune system. This study provided some evidence that there is a higher possibility for SARS to reoccur in spring than that in autumn and winter. CONCLUSION: Current knowledge based on case studies of the SARS outbreak in the four cities suggested that the SARS outbreaks were significantly associated with the temperature and its variations. However, because the fallacy and the uncontrolled confounding effects might have biased the results, the possibility of other meteorological factors having an affect on the SARS outbreaks deserves further investigation.     

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。     

严重急性呼吸综合征患者血清超氧化物歧化酶含量的动态观察

目的观察SAPS患者血清超氧化物歧化酶(SOD)含量变化。方法用放射免疫法检测29例SAILS患者血清SOD含量，与正常对照组作了比较。结果患者SOD含量明显低于对照组，重型SARS患者SOD含量明显低于普通型。恢复期不同阶段患者血清SOD含量回升但仍低于对照组。结论SAILS患者体内产生过量的自由基分子，使SOD过度消耗。SOD含量变化可以反映病情程度，检测血清SOD水平有助于病情的观察。加强机体清除自由基的能力可能是重要的治疗措施之一。     

SARS in hospital emergency room

Thirty-one cases of severe acute respiratory syndrome (SARS) occurred after exposure in the emergency room at the National Taiwan University Hospital. The index patient was linked to an outbreak at a nearby municipal hospital. Three clusters were identified over a 3-week period. The first cluster (5 patients) and the second cluster (14 patients) occurred among patients, family members, and nursing aids. The third cluster (12 patients) occurred exclusively among healthcare workers. Six healthcare workers had close contact with SARS patients. Six others, with different working patterns, indicated that they did not have contact with a SARS patient. Environmental surveys found 9 of 119 samples of inanimate objects to be positive for SARS coronavirus RNA. These observations indicate that although transmission by direct contact with known SARS patients was responsible for most cases, environmental contamination with the SARS coronavirus may have lead to infection among healthcare workers without documented contact with known hospitalized SARS patients.     

Chimeric severe acute respiratory syndrome coronavirus (SARS-CoV) S glycoprotein and influenza matrix 1 efficiently form virus-like particles (VLPs) that protect mice against challenge with SARS-CoV

SARS-CoV was the cause of the global pandemic in 2003 that infected over 8000 people in 8 months. Vaccines against SARS are still not available. We developed a novel method to produce high levels of a recombinant SARS virus-like particles (VLPs) vaccine containing the SARS spike (S) protein and the influenza M1 protein using the baculovirus insect cell expression system. These chimeric SARS VLPs have a similar size and morphology to the wild type SARS-CoV. We tested the immunogenicity and protective efficacy of purified chimeric SARS VLPs and full length SARS S protein vaccines in a mouse lethal challenge model. The SARS VLP vaccine, containing 0.8 μg of SARS S protein, completely protected mice from death when administered intramuscular (IM) or intranasal (IN) routes in the absence of an adjuvant. Likewise, the SARS VLP vaccine, containing 4 μg of S protein without adjuvant, reduced lung virus titer to below detectable level, protected mice from weight loss, and elicited a high level of neutralizing antibodies against SARS-CoV. Sf9 cell-produced full length purified SARS S protein was also an effective vaccine against SARS-CoV but only when co-administered IM with aluminum hydroxide. SARS-CoV VLPs are highly immunogenic and induce neutralizing antibodies and provide protection against lethal challenge. Sf9 cell-based VLP vaccines are a potential tool to provide protection against novel pandemic agents.     

Management of inpatients exposed to an outbreak of severe acute respiratory syndrome (SARS)

This is a prospective observational study of a cohort of inpatients exposed to a severe acute respiratory syndrome (SARS) outbreak. Strict infection control policies were instituted. The 70 patients exposed to the SARS outbreak were isolated from the rest of the hospital. They were triaged, quarantined and cohorted in three open plan wards. Selective isolation was carried out immediately when symptoms and signs suspicious of SARS manifested clinically. The patients' ages ranged from 21 to 90 years and 56% had surgery before the quarantine. Sixteen patients with unexplained fever during the period of quarantine were isolated, seven of whom were eventually diagnosed with probable SARS. The crude incidence of SARS in our cohort was 10%. The SARS case fatality was 14%. No secondary transmission of the SARS virus within the cohort was observed. Strict infection control, together with appropriate triaging, cohorting and selective isolation, is an effective and practical model of intervention in cohorts exposed to a SARS outbreak. Such a management strategy eases the logistic constraints imposed by demands for large numbers of isolation facilities in the face of a massive outbreak.     

Infection control for SARS in a tertiary paediatric centre in Hong Kong

Severe acute respiratory syndrome (SARS) is an emerging infectious disease. After the appearance of an index patient in Hong Kong in February 2003, SARS outbreaks occurred rapidly in hospitals and spread to the community. The aim of this retrospective study is to evaluate the effectiveness of a triage policy and risk-stratified infection control measures in preventing nosocomial SARS infection among paediatric healthcare workers (HCWs) at the Prince of Wales Hospital, a general hospital to which children with SARS are referred in Hong Kong. The acute paediatric wards were stratified into three areas: (1) ultra high-risk area, (2) high-risk area and (3) moderate-risk area according to different risk levels of nosocomial SARS transmission. The implementation of different levels of infection control precautions was guided by this risk stratification strategy. Between 13 March and 23 June, 38 patients with probable and suspected SARS, 90 patients with non-SARS pneumonia, and 510 patients without pneumonia were admitted into our unit. All probable SARS cases were isolated in negative-pressure rooms. Twenty-six HCWs worked in the ultra high-risk area caring for SARS patients and 88 HCWs managed non-SARS patients in other ward areas. None of the HCWs developed clinical features suggestive of SARS. In addition, there was no nosocomial spread of SARS-associated coronavirus to other patients or visitors during this period. In conclusion, stringent infection control precautions, appropriate triage and prompt isolation of potential SARS patients may have contributed to a lack of nosocomial spread and HCW acquisition of SARS in our unit.     

Environmental factors on the SARS epidemic: air temperature, passage of time and multiplicative effect of hospital infection

The study sought to identify factors involved in the emergence, prevention and elimination of severe acute respiratory syndrome (SARS) in Hong Kong during 11 March to 22 May 2003. A structured multiphase regression analysis was used to estimate the potential effects of weather, time and interaction effect of hospital infection. In days with a lower air temperature during the epidemic, the risk of increased daily incidence of SARS was 18.18-fold (95% confidence interval 5.6-58.8) higher than in days with a higher temperature. The total daily new cases might naturally decrease by an average of 2.8 patients for every 10 days during the epidemic. The multiplicative effect of infected hospital staff with patients in an intensive care unit (ICU) and the proportion of SARS patients in ICUs might respectively increase the risk of a larger SARS epidemic in the community. The provision of protective gear in hospitals was also a very important factor for the prevention of SARS infection. SARS transmission appeared to be dependent on seasonal temperature changes and the multiplicative effect of hospital infection. SARS also appeared to retreat naturally over time.     

Epidemiologic study and containment of a nosocomial outbreak of severe acute respiratory syndrome in a medical center in Kaohsiung, Taiwan.

OBJECTIVE: We conducted an epidemiologic investigation at the beginning of a nosocomial outbreak of severe acute respiratory syndrome (SARS) to clarify the dynamics of SARS transmission, the magnitude of the SARS outbreak, and the impact of the outbreak on the community. METHODS: We identified all potential cases of nosocomially acquired SARS, linked them to the most likely infection source, and described the hospital containment measures. SETTING: A 2,300-bed medical center in Kaohsiung, Taiwan. RESULTS: A total of 55 cases of SARS were identified, and 227 hospital workers were quarantined. The index patient and neighboring patients were isolated. A chest physician team reviewed medical charts and chest radiographs and monitored the development of SARS in patients staying in the ward. The presence of underlying lung disease and immunocompromise in some patients made the diagnosis of SARS difficult. Some cases of SARS were diagnosed after the patients had died. Medical personnel were infected only if they cared for patients with unrecognized SARS, and caretakers played important roles in transmission of SARS to family members. As the number of cases of nosocomial SARS increased, the hospital closed the affected ward and expedited construction of negative-pressure rooms on other vacated floors for patient cohorting, and the last case in the hospital was identified 1 week later. CONCLUSIONS: Timely recognition of SARS is extremely important. However, given the limitations of SARS testing, possible loss of epidemic links, and the nonspecific clinical presentations in hospitalized patients, it is very important to establish cohorts of persons with low, medium, and high likelihoods of SARS acquisition. Rapid closure of affected wards may minimize the impact on hospital operations. Establishment of hospitals dedicated to appropriate treatment of patients with SARS might minimize the impact of the disease in future epidemics.     

The SARS outbreak in a general hospital in Tianjin, China -- the case of super-spreader

Severe acute respiratory syndrome (SARS) is a newly emerged infectious disease with a high case-fatality rate and devastating socio-economic impact. In this report we summarized the results from an epidemiological investigation of a SARS outbreak in a hospital in Tianjin, between April and May 2003. We collected epidemiological and clinical data on 111 suspect and probable cases of SARS associated with the outbreak. Transmission chain and outbreak clusters were investigated. The outbreak was single sourced and had eight clusters. All SARS cases in the hospital were traced to a single patient who directly infected 33 people. The patients ranged from 16 to 82 years of age (mean age 38.5 years); 38.7% were men. The overall case fatality in the SARS outbreak was 11.7% (13/111). The outbreak lasted around 4 weeks after the index case was identified. SARS is a highly contagious condition associated with substantial case fatality; an outbreak can result from one patient in a relatively short period. However, stringent public health measures seemed to be effective in breaking the disease transmission chain.     

广东省医务人员SARS危险因素的流行病学研究

目的 了解医务人员SARS感染的危险因素，为采取有效对策提供依据。方法 对广东省收治SAPS病人的9家医院的1645名医务人员进行病例对照研究。结果 SARS流行期间医务人员工作场所通风良好、防护意识强、使用联体衣帽防护服装、使用一次性无纺口罩、每次接触病人后手消毒、使用非接触式洗手装置、避免疲劳nr减少SARS感染机会。结论 控制SARS有关的危险因素，做好医务人员的防护工作，对SARS的防制具有重要意义。     

定量评价SARS干预措施效果的传播动力学模型

目的建立一种可以用于严重急性呼吸综合征(SARS)干预措施效果定量评价的传播动力学模型。方法根据SARS流行规律,以传染病SEIR流行模型为基础,增设病例管理人群和控制措施相关参数,从而建立起SARS的传播动力学模型。以北京市2003年SARS流行为实例,说明所建模型在干预措施效果定量评价上的应用。结果所建立的模型可以随时调整干预措施相关参数。通过干预情景假定,可以模拟各种干预措施情况下SARS的流行过程,从而对干预措施效果做出定量评价。实例研究发现,该模型可以较好地模拟北京市2003年SARS流行过程;北京市2003年4月20日前后采取的措施对SARS疫情控制起到了关键性的作用。结论所建立的SARS流行模型是可靠和稳定的,可以用于SARS干预措施效果的定量评价。     

广西重点人群传染性非典型肺炎监测研究

目的为了及时发现和监控传染性非典型肺炎病例,防止疫情扩散和蔓延,探讨影响疫情发生和发展的因素.方法采用主动与被动相结合的疾病监测方法,在全区范围内对从外地返乡、来桂人群、非典病人密切接触者、发热病人实施监测.结果自2003年4月15日至2003年7月10日,全区组织1076万日人次参与重点人群监测,共监测排查从外省(市)返乡人员625 646人,其中从广东返乡501 596人,累计发现发热病人7067人,确诊为非典病例6例;监测来桂人群201 158人,其中从广东来51 288人,发现发热病人981人,未查出非典病例;隔离观察非典密切接触者2213人,发现非典2例,发病率达90.4/10万;发热门诊接诊709 843例发热病人,其中有3例确诊为非典病例也系返乡民工.结论通过这次大范围监测,广西自4月中旬以后发生的11例非典病人均能在第一时间(48h内)得以发现和监控,有效防止了疫情扩散和蔓延.监测结果还表明广西尚属输入性地区,未发生流行,受到邻省疫情威胁不很严重;同时显示一些市(县)开展人群监测有一定程度过度反应,付出的代价昂贵,急需建立起更高效经济可行适合常态管理的监测手段.     

The 2003 SARS outbreak and its impact on infection control practices

Severe Acute Respiratory Syndrome (SARS) emerged recently as a new infectious disease that was transmitted efficiently in the healthcare setting and particularly affected healthcare workers (HCWs), patients and visitors. The efficiency of transmission within healthcare facilities was recognised following significant hospital outbreaks of SARS in Canada, China, Hong Kong, Singapore, Taiwan and Vietnam. The causative agent of SARS was identified as a novel coronavirus, the SARS coronavirus. This was largely spread by direct or indirect contact with large respiratory droplets, although airborne transmission has also been reported. High infection rates among HCWs led initially to the theory that SARS was highly contagious and the concept of 'super-spreading events'. Such events illustrated that lack of infection control (IC) measures or failure to comply with IC precautions could lead to large-scale hospital outbreaks. SARS was eventually contained by the stringent application of IC measures that limited exposure of HCWs to potentially infectious individuals. As the 'global village' becomes smaller and other microbial threats to health emerge, or re-emerge, there is an urgent need to develop a global strategy for infection control in hospitals. This paper provides an overview of the main IC practices employed during the 2003 SARS outbreak, including management measures, dedicated SARS hospitals, personal protective equipment, isolation, handwashing, environmental decontamination, education and training. The psychological and psychosocial impact on HCWs during the outbreak are also discussed. Requirements for IC programmes in the post-SARS period are proposed based on the major lessons learnt from the SARS outbreak.     

Severe acute respiratory syndrome (SARS): knowledge, attitudes, practices and sources of information among physicians answering a SARS fever hotline service

In June 2003, Taiwan introduced a severe acute respiratory syndrome (SARS) telephone hotline service to provide concerned callers with rapid access to information, advice and appropriate referral where necessary. This paper reports an evaluation of the knowledge, attitude, practices and sources of information relating to SARS among physicians who staffed the SARS fever hotline service. A retrospective survey was conducted using a self-administered postal questionnaire. Participants were physicians who staffed a SARS hotline during the SARS epidemic in Taipei, Taiwan from June 1 to 10, 2003. A response rate of 83% was obtained. All respondents knew the causative agent of SARS, and knowledge regarding SARS features and preventive practices was good. However, only 54% of respondents knew the incubation period of SARS. Hospital guidelines and news media were the major information sources. In responding to two case scenarios most physicians were likely to triage callers at high risk of SARS appropriately, but not callers at low risk. Less than half of all respondents answered both scenarios correctly. The results obtained suggest that knowledge of SARS was generally good although obtained from both medical and non-medical sources. Specific knowledge was however lacking in certain areas and this affected the ability to appropriately triage callers. Standardized education and assessment of prior knowledge of SARS could improve the ability of physicians to triage callers in future outbreaks.     

从SARS科研反思科研体制

目的 反思SARS科研工作，引起更多更深人的科研体制改革的讨论，进一步促进科研工作。方法 回顾SARS在中国的出现和流行，国内外SARS科研工作情况，分析中国SARS科研工作失利的原因和科研体制存在的问题。结果 SARS科研工作缺乏统一、有效地联合机制。结论 建立应对公共卫生事件科研机制迫在眉睫。     

Border screening for SARS

With the rapid international spread of severe acute respiratory syndrome (SARS) from March through May 2003, Canada introduced various measures to screen airplane passengers at selected airports for symptoms and signs of SARS. The World Health Organization requested that all affected areas screen departing passengers for SARS symptoms. In spite of intensive screening, no SARS cases were detected. SARS has an extremely low prevalence, and the positive predictive value of screening is essentially zero. Canadian screening results raise questions about the effectiveness of available screening measures for SARS at international borders.     

重症SARS病人死亡危险因素的Logistic回归分析

目的分析重症SARS病人死亡的危险因素.方法利用单因素、多因素非条件Logistic回归对54例重症SARS病例的18个危险因素进行分析.结果年龄(OR=7.351,=0.042)、有无心血管系统并发症(OR=24.381,=0.035)、有无采用人工辅助通气(0R=43.905,=0.002)是重症SARS病人预后的主要影响因素,人工辅助通气为病情指标.结论高龄、伴有呼吸衰竭和心血管系统并发症的重症SARS患者预后较差.     

88例SARS密切接触者流行病学调查

目的　探讨SARS密切接触者中是否有隐性感染者及评估防制措施的落实情况。方法　对广元市 88名SARS患者密切接触者进行随访 ,用“SARS病例密切接触者调查问卷”调查密切接触者的人口学特征、接触情况、防护情况及身体状况 ,用酶联免疫双抗原夹心法检测血清中特异性SARS冠状病毒总抗体水平。结果　 4名医务工作者检出SARS病毒总抗体阳性 ,阳性率 4 5 % ;密切接触者的个人综合防护率为 14 8% ;医务防疫人员在国家将SARS纳入法定传染病管理前后 ,个人综合防护率有显著提高 (R控制前 =9 5 % ;R控制后 =2 9 1% ,P <0 0 5 )。结论　SABS密切接触者中存在隐性感染者 ;及早采取综合防制措施可有效控制SARS的流行 ;加强高危人群个人防护和控制医院内感染是防制工作的重点