Update: severe acute respiratory syndrome--Toronto,Canada, 2003

Severe acute respiratory syndrome (SARS) was first recognized in Toronto in a woman who returned from Hong Kong on February 23, 2003 (1). Transmission to other persons resulted subsequently in an outbreak among 257 persons in several Greater Toronto Area (GTA) hospitals. After implementation of provincewide public health measures that included strict infection-control practices, the number of recognized cases of SARS declined substantially, and no cases were detected after April 20. On April 30, the World Health Organization (WHO) lifted a travel advisory issued on April 22 that had recommended limiting travel to Toronto. This report describes a second wave of SARS cases among patients, visitors, and health-care workers (HCWs) that occurred at a Toronto hospital approximately 4 weeks after SARS transmission was thought to have been interrupted. The findings indicate that exposure to hospitalized patients with unrecognized SARS after a provincewide relaxation of strict SARS control measures probably contributed to transmission among HCWs. The investigation underscores the need for monitoring fever and respiratory symptoms in hospitalized patients and visitors, particularly after a decline in the number of reported SARS cases.     

Severe acute respiratory syndrome (SARS) and healthcare workers

The recent outbreak of severe acute respiratory synt drome (SARS) was spread by international air travel, a direct result of globalization. The disease is caused by a novel coronavirus, transmitted from human to human by droplets or by direct contact. Healthcare workers (HCWs) were at high risk and accounted for a fifth of all cases globally. Risk factors for infection in HCWs included lack of awareness and preparedness when the disease first struck, poor institutional infection control measures, lack of training in infection control procedures, poor compliance with the use of personal protection equipment (PPE), exposure to high-risk procedures such as intubation and nebulization, and exposure to unsuspected SARS patients. Measures to prevent nosocomial infection included establishing isolation wards for triage, SARS patients, and step-down; training and monitoring hospital staff in infection-control procedures; active and passive screening of HCWs; enforcement of droplet and contact precautions; and compliance with the use of PPE.     

Asymptomatic SARS coronavirus infection among healthcare workers, Singapore

We conducted a study among healthcare workers (HCWs) exposed to patients with severe acute respiratory syndrome (SARS) before infection control measures were instituted. Of all exposed HCWs, 7.5% had asymptomatic SARS-positive cases. Asymptomatic SARS was associated with lower SARS antibody titers and higher use of masks when compared to pneumonic SARS.     

Cluster of cases of severe acute respiratory syndrome among Toronto healthcare workers after implementation of infection control precautions: a case series.

OBJECTIVE: To review the severe acute respiratory syndrome (SARS) infection control practices, the types of exposure to patients with SARS, and the activities associated with treatment of such patients among healthcare workers (HCWs) who developed SARS in Toronto, Canada, after SARS-specific infection control precautions had been implemented. METHODS: A retrospective review of work logs and patient assignments, detailed review of medical records of patients with SARS, and comprehensive telephone-based interviews of HCWs who met the case definition for SARS after implementation of infection control precautions. RESULTS: Seventeen HCWs from 6 hospitals developed disease that met the case definition for SARS after implementation of infection control precautions. These HCWs had a mean age (+/-SD) of 39+/-2.3 years. Two HCWs were not interviewed because of illness. Of the remaining 15, only 9 (60%) reported that they had received formal infection control training. Thirteen HCWs (87%) were unsure of proper order in which personal protective equipment should be donned and doffed. Six HCWs (40%) reused items (eg, stethoscopes, goggles, and cleaning equipment) elsewhere on the ward after initial use in a room in which a patient with SARS was staying. Use of masks, gowns, gloves, and eyewear was inconsistent among HCWs. Eight (54%) reported that they were aware of a breach in infection control precautions. HCWs reported fatigue due to an increased number and length of shifts; participants worked a median of 10 shifts during the 10 days before onset of symptoms. Seven HCWs were involved in the intubation of a patient with SARS. One HCW died, and the remaining 16 recovered. CONCLUSION: Multiple factors were likely responsible for SARS in these HCWs, including the performance of high-risk patient care procedures, inconsistent use of personal protective equipment, fatigue, and lack of adequate infection control training.     

Nosocomial transmission of Mycobacterium tuberculosis found through screening for severe acute respiratory syndrome--Taipei, Taiwan, 2003

The emergence of severe acute respiratory syndrome (SARS) has highlighted the importance of hospital infection-control programs. Prevention of Mycobacterium tuberculosis transmission also requires effective infection control in health-care facilities. In Taipei, Taiwan, an area with moderate to high incidence of tuberculosis (TB) (50-74 cases per 100,000 population), health-care workers (HCWs) are at increased risk for M. tuberculosis (Taiwan Center for Disease Control, unpublished data, 2002). In April 2003, SARS-related screening in a hospital in Taipei resulted in the detection of suspected TB among HCWs. This report summarizes how SARS screening led to the discovery of 60 cases of TB. HCWs in Taiwan should remain vigilant for cases of TB so persons suspected of having TB are evaluated and treated promptly.     

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.     

Risk factors for SARS among persons without known contact with SARS patients, Beijing, China

Most cases of severe acute respiratory syndrome (SARS) have occurred in close contacts of SARS patients. However, in Beijing, a large proportion of SARS cases occurred in persons without such contact. We conducted a case-control study in Beijing that compared exposures of 94 unlinked, probable SARS patients with those of 281 community-based controls matched for age group and sex. Case-patients were more likely than controls to have chronic medical conditions or to have visited fever clinics (clinics at which possible SARS patients were separated from other patients), eaten outside the home, or taken taxis frequently. The use of masks was strongly protective. Among 31 case-patients for whom convalescent-phase (>21 days) sera were available, 26% had immunoglobulin G to SARS-associated coronavirus. Our finding that clinical SARS was associated with visits to fever clinics supports Beijing's strategy of closing clinics with poor infection-control measures. Our finding that mask use lowered the risk for disease supports the community's use of this strategy.     

Which preventive measures might protect health care workers from SARS?

Background  

Despite the use of a series of preventive measures, a high incidence of severe acute respiratory syndrome (SARS) was observed among health care workers (HCWs) during the SARS epidemic. This study aimed to determine which preventive measures may have been effective in protecting HCWs from infection, and which were not effective.     

Factors associated with critical-care healthcare workers' adherence to recommended barrier precautions during the Toronto severe acute respiratory syndrome outbreak.

OBJECTIVE: To assess factors associated with adherence to recommended barrier precautions among healthcare workers (HCWs) providing care to critically ill patients with severe acute respiratory syndrome (SARS). SETTING: Fifteen acute care hospitals in Ontario, Canada. DESIGN: Retrospective cohort study. PATIENTS: All patients with SARS who required intubation during the Toronto SARS outbreak in 2003. PARTICIPANTS: HCWs who provided care to or entered the room of a SARS patient during the period from 24 hours before intubation until 4 hours after intubation. METHODS: Standardized interviews were conducted with eligible HCWs to assess their interactions with the SARS patient, their use of barrier precautions, their practices for removing personal protective equipment, and the infection control training they received. RESULTS: Of 879 eligible HCWs, 795 (90%) participated. In multivariate analysis, the following predictors of consistent adherence to recommended barrier precautions were identified: recognition of the patient as a SARS case (odds ratio [OR], 2.5 [95% confidence interval {CI}, 1.5-4.5); recent infection control training (OR for interactive training, 2.7 [95% CI, 1.7-4.4]; OR for passive training, 1.7 [95% CI, 1.0-3.0]), and working in a SARS unit (OR, 4.0 [95% CI, 1.8-8.9]) or intensive care unit (OR, 4.3 [95% CI, 2.0-9.0]). Two factors were associated with significantly lower rates of consistent adherence: the provision of care for patients with higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (OR for score APACHE II of 20 or greater, 0.4 [95% CI, 0.28-0.68]) and work on shifts that required more frequent room entry (OR for 6 or more entries per shift, 0.5 [95% CI, 0.32-0.86]). CONCLUSIONS: There were significant deficits in knowledge about self-protection that were partially corrected by education programs during the SARS outbreak. HCWs' adherence to self-protection guidelines was most closely associated with whether they provided care to patients who had received a definite diagnosis of SARS.     

Using an integrated infection control strategy during outbreak control to minimize nosocomial infection of severe acute respiratory syndrome among healthcare workers

Healthcare workers (HCWs) are at risk of acquiring severe acute respiratory syndrome (SARS) while caring for SARS patients. Personal protective equipment and negative pressure isolation rooms (NPIRs) have not been completely successful in protecting HCWs. We introduced an innovative, integrated infection control strategy involving triaging patients using barriers, zones of risk, and extensive installation of alcohol dispensers for glove-on hand rubbing. This integrated infection control approach was implemented at a SARS designated hospital ('study hospital') where NPIRs were not available. The number of HCWs who contracted SARS in the study hospital was compared with the number of HCWs who contracted SARS in 86 Taiwan hospitals that did not use the integrated infection control strategy. Two HCWs contracted SARS in the study hospital (0.03 cases/bed) compared with 93 HCWs in the other hospitals (0.13 cases/bed) during the same three-week period. Our strategy appeared to be effective in reducing the incidence of HCWs contracting SARS. The advantages included rapid implementation without NPIRs, flexibility to transfer patients, and re-inforcement for HCWs to comply with infection control procedures, especially handwashing. The efficacy and low cost are major advantages, especially in countries with large populations at risk and fewer economic resources.     

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--Taiwan, 2003

On April 22, 2003, the Taiwan Department of Health (DOH) was notified of seven cases of severe acute respiratory syndrome (SARS) among health-care workers (HCWs) at a large municipal hospital in Taipei (hospital A). Subsequent cases at eight hospitals have been associated with exposures at hospital A. Previously, all reported cases had been associated with persons recently returning to Taiwan from SARS-affected regions. This report summarizes epidemiologic findings of the outbreak in Taiwan and describes the impact of health-care--associated transmission of SARS.     

我市医务人员严重急性呼吸综合征医院感染流行原因调查与对策

目的 调查某市医务人员感染严重急性呼吸综合征(severe acute respiratory syndrome，SARS)的途径及危险因素。方法 对直接参加过抢救和间接接触SARS患而被感染的医务人员采取统一填表、座谈、走访、电话采访等方式进行调查。结果 调查三所医院感染SARS的医务人员共88人，占全市发病医务人员总人数的87．13％。导致医务人员易感的原因是：对疾病缺乏认识，防范意识不强；管理网络不健全；患隐瞒流行病史；隔离环境及防护用品达不到要求等。结论 重视医院感染管理及对医务人员的医院感染知识培训，强化消毒隔离和自我保护意识，是控制医院感染流行及保护医务人员的有力措施。     

医护人员预防SARS医院内感染的个人防护措施效果评价

目的 评价医务人员预防SARS医院内感染个人防护措施的效果,验证SARS的传播途径。方法 在广东省10家收治SARS患者的主要医院进行了成组设计的病例对照研究,对象为常规参加SARS诊治工作且直接抢救重患者的医护人员,共257人,其中病例组77例,对照组180人。采用统一调查表了解调查对象接触SARS患者程度、个人防护情况、卫生习惯、预防服药等方面情况。单因素分析采用X2检验、多因素分析利用非条件logistic回归分析。并用趋势X2检验分析个人防护措施的剂量反应关系和联合使用效果。结果 单因素分析结果显示,一直戴12层及以上口罩、穿隔离衣、用鞋套、戴手套、必要时戴眼罩、消毒洗手、漱口液漱口、用滴鼻滴眼液保护鼻眼黏膜、及时洗澡换衣、“不在病区吃饭/饮水/抽烟”、服oseltamivir phosphate等均有保护作用(P<0.05)。非条件logistic多因素回归分析有显著意义的有戴口罩(OR=0.78,95％CI:0.60～0.99)、戴眼罩(OR=0.20,95％CI:0.10～0.41)和穿鞋套(OR=0.58,95％CI:0.39～0.86)。并且趋势分析显示口罩及口罩类型、穿隔离衣、用鞋套、戴手套、必要时戴眼罩、漱口液漱口、用滴鼻滴眼液保护鼻眼黏膜和及时洗澡换衣等措施存在剂量效应关系。无防护参与SARS患者抢救的医护人员的罹患率高达61.5％(16/26),保护率随防     

一起SARS超级传播者引起医院内传播的调查

目的 了解传染性非典型肺炎(SARS)超级传播的传染性及其造成SARS医院内传播的情况。方法 调查2003年3月22日至4月15日江门市某医院1例SARS病例及其导致院内传播的其他SARS病例。对SARS病例住院病历、流行病学现场调查资料和特异性实验室检查资料进行分析。结果 该医院首例SARS病例于3月22日入院，4月1日确诊为SARS，4月2日死亡。4月2～15日该医院除了首例SARS病例外共报告SARS病例22例。除最后1例患在首例患死亡后第七天才进入曾诊治过该患的肾内科外，其余21例SARS患均与首例患有明确接触史。对4月2～13日发病的21例患分析结果显示，发病高峰为4月3～7日，占病例总数的71．43％(15／21)；19例患均为诊治首例患的肾内科的医护人员，该科室罹患率为59．38％(19／32)，另2例分别为同时在肾内科住院的患及陪护；估算病例潜伏期中位数为6d；对其中的11例病例进行血清SARS抗体．测定和PCR检测，结果均为单项或两项检验结果阳性。结论 证实是一起医院内传播的SARS流行；引起传播的关键原因是首例病例表现“不典型性”，医护人员欠缺防护，SARS病毒传染性强以及病区的布局不合理等因素；采取病区改造、加强医护人员的防护等一系列预防控制措施，尤其加强医院感染控制可以阻断流行。     

Transmission of hepatitis B virus among persons undergoing blood glucose monitoring in long-term-care facilities--Mississippi, North Carolina, and Los Angeles County, California, 2003-2004

Regular monitoring of blood glucose levels is an important component of routine diabetes care. Capillary blood is typically sampled with the use of a fingerstick device and tested with a portable glucometer. Because of outbreaks of hepatitis B virus (HBV) infections associated with glucose monitoring, CDC and the Food and Drug Administration (FDA) have recommended since 1990 that fingerstick devices be restricted to individual use. This report describes three recent outbreaks of HBV infection among residents in long-term-care (LTC) facilities that were attributed to shared devices and other breaks in infection-control practices related to blood glucose monitoring. Findings from these investigations and previous reports suggest that recommendations concerning standard precautions and the reuse of fingerstick devices have not been adhered to or enforced consistently in LTC settings. The findings underscore the need for education, training, adherence to standard precautions, and specific infection-control recommendations targeting diabetes-care procedures in LTC settings.     

Combining clinical and epidemiologic features for early recognition of SARS

Early recognition and rapid initiation of infection control precautions are currently the most important strategies for controlling severe acute respiratory syndrome (SARS). No rapid diagnostic tests currently exist that can rule out SARS among patients with febrile respiratory illnesses. Clinical features alone cannot with certainty distinguish SARS from other respiratory illnesses rapidly enough to inform early management decisions. A balanced approach to screening that allows early recognition of SARS without unnecessary isolation of patients with other respiratory illnesses will require clinicians not only to look for suggestive clinical features but also to routinely seek epidemiologic clues suggestive of SARS coronavirus exposure. Key epidemiologic risk factors include 1) exposure to settings where SARS activity is suspected or documented, or 2) in the absence of such exposure, epidemiologic linkage to other persons with pneumonia (i.e., pneumonia clusters), or 3) exposure to healthcare settings. When combined with clinical findings, these epidemiologic features provide a possible strategic framework for early recognition of SARS.     

如何预防医务人员COVID-19感染：来自中国武汉的经验

 在新型冠状病毒肺炎（COVID-19）大流行的背景下,全球已有数以千计的医务人员感染新型冠状病毒（SARS-CoV-2）,并有人因此失去生命。在疫情早期,中国发生了医务人员感染。由于对SARS-CoV-2的特点认识有限,湖北有3,000多名医务人员在疫情暴发初期感染了SARS-CoV-2。由于当地医院医务人员工作超负荷,超过4.2万名医务人员（包括军队医务人员）,从全国各地被派往湖北。在疫情最严重的时期,中国有十分之一的重症监护医生在武汉工作。在中国抗击COVID-19的过程中,虽然在疫情早期发生了一定数量的医务人员感染SARS-CoV-2,但通过及时采取预防措施,包括快速诊断,及时对患者进行隔离,强调医务人员的安全,加强医务人员基本防护知识培训和统一管理等有效防护措施,国家援鄂医疗队42,632名队员最终未报告感染,并且当地医院医务人员感染病例显著减少,说明医务人员院内感染COVID-19是完全可以预防的。本文旨在阐述中国武汉疫情期间,如何通过采取有效措施预防医务人员感染SARS-CoV-2。     

Research gaps in protecting healthcare workers from SARS and other respiratory pathogens: an interdisciplinary, multi-stakeholder, evidence-based approach

OBJECTIVE: To identify priorities for further research in protecting healthcare workers (HCWs) from severe acute respiratory syndrome (SARS) and other respiratory pathogens by summarizing the basic science of infectious bioaerosols and the efficacy of facial protective equipment; the organizational, environmental, and individual factors that influence the success of infection control and occupational health programs; and factors identified by HCWs as important. METHOD: An extensive literature review was conducted and 15 focus groups held, mostly with frontline HCWs in Toronto. Critical gaps in knowledge were identified and prioritized. RESULTS: Highest priority was given to organizational factors that create a climate of safety. Other priority areas included understanding aerosolization risks and practical measures to control bioaerosols at the source. CONCLUSIONS: Further research is warranted to improve safety climate in health care and, specifically, to provide greater protection against respiratory pathogens.