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.     

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.     

Time from Exposure to Diagnosis among Quarantined Close Contacts of SARS-CoV-2 Omicron Variant Index Case-Patients,South Korea

To determine optimal quarantine duration, we evaluated time from exposure to diagnosis for 107 close contacts of severe acute respiratory syndrome coronavirus 2 Omicron variant case-patients. Average time from exposure to diagnosis was 3.7 days; 70% of diagnoses were made on day 5 and 99.1% by day 10, suggesting 10-day quarantine.     

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.     

Efficiency of quarantine during an epidemic of severe acute respiratory syndrome--Beijing, China, 2003

During March--July 2003, an epidemic of severe acute respiratory syndrome (SARS) in Beijing, China, accounted for 2,521 probable cases (attack rate: 19 per 100,000 population). To control the epidemic, public health officials initiated enhanced surveillance, isolation of SARS patients, use of personal protective equipment (PPE) by health-care workers, and quarantine of contacts of known SARS patients. Approximately 30,000 Beijing residents were quarantined in their homes or quarantine sites. To guide future quarantine policy, the Chinese Field Epidemiology Training Program (China FETP) of the Chinese Center for Disease Control and Prevention (China CDC) conducted a survey to estimate the risk for acquiring SARS among quarantined residents of Haidian District (2001 population: 2.24 million), Beijing, in May 2003, 1 month after the epidemic peaked. This report summarizes the results of that survey, which indicate that, as a component of a comprehensive SARS-control program, quarantine should be limited to persons who have contact with an actively ill SARS patient in the home or hospital, allowing for better focus of resources in future outbreaks.     

Hospital preparedness and SARS

On May 23, 2003, Toronto experienced the second phase of a severe acute respiratory syndrome (SARS) outbreak. Ninety cases were confirmed, and >620 potential cases were managed. More than 9,000 persons had contact with confirmed or potential case-patients; many required quarantine. The main hospital involved during the second outbreak was North York General Hospital. We review this hospital's response to, and management of, this outbreak, including such factors as building preparation and engineering, personnel, departmental workload, policies and documentation, infection control, personal protective equipment, training and education, public health, management and administration, follow-up of SARS patients, and psychological and psychosocial management and research. We also make recommendations for other institutions to prepare for future outbreaks, regardless of their origin.     

SARS outbreak in Germany 2003: workload of local health departments and their compliance in quarantine measures--implications for outbreak modeling and surge capacity?

OBJECTIVE: Public health management of severe acute respiratory syndrome epidemic must be evaluated to improve contingency planning for epidemics. METHODS: Standardized questionnaires on case management were sent to local health departments of 15 of 16 states in Germany. RESULTS: Of the 384 local health departments who received the questionnaire, 280 (72%) completed them. They reported 271 suspect or probable severe acute respiratory syndrome cases under investigation (average 4.7). The average duration of quarantine was 5.4 days. Contacts without professional activity were 2.78 times more likely to stay under 10-day quarantine than those with professional activity (CI: 0.80-9.86). Local health departments with at least one case under investigation had invested an average of 104.5 working hours. CONCLUSIONS: Our contact-case ratios may serve for planning for modeling in epidemics. We found discrepancies between local and national surveillance figures; home quarantine was frequently not applied as recommended and the burden on urban health departments was disproportionally higher. Flexibility of the national surveillance system and surge capacity for the prevention of future epidemics need improvement, particularly in urban health departments.     

Childcare Exposure to Severe Acute Respiratory Syndrome Coronavirus 2 for 4-Year-Old Presymptomatic Child,South Korea

Data on transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from preschool-age children to children and adults are limited. We investigated SARS-CoV-2 exposure at a childcare center in South Korea. A 4-year-old child, probably infected by his grandmother, attended the center during the presymptomatic period (February 19–21, 2020). Fever developed on February 22, and he was given a diagnosis SARS-CoV-2 infection on February 27. At the center, 190 persons (154 children and 36 adults) were identified as contacts; 44 (23.2%) were defined as close contacts (37 children and 7 adults). All 190 persons were negative for SARS-CoV-2 on days 8–9 after the last exposure. Two close contacts (1 child and 1 adult) showed development of symptoms on the last day of quarantine. However, subsequent test results were negative. This investigation adds indirect evidence of low potential infectivity in a childcare setting with exposure to a presymptomatic child.     

Lack of SARS transmission and U.S. SARS case-patient

In early April 2003, severe acute respiratory syndrome (SARS) was diagnosed in a Pennsylvania resident after his exposure to persons with SARS in Toronto, Canada. To identify contacts of the case-patient and evaluate the risk for SARS transmission, a detailed epidemiologic investigation was performed. On the basis of this investigation, 26 persons (17 healthcare workers, 4 household contacts, and 5 others) were identified as having had close contact with this case-patient before infection-control practices were implemented. Laboratory evaluation of clinical specimens showed no evidence of transmission of SARS-associated coronavirus (SARS-CoV) infection to any close contact of this patient. This investigation documents that, under certain circumstances, SARS-CoV is not readily transmitted to close contacts, despite ample unprotected exposures. Improving the understanding of risk factors for transmission will help focus public health control measures.     

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.     

Public health interventions and SARS spread, 2003

The 2003 outbreak of severe acute respiratory syndrome (SARS) was contained largely through traditional public health interventions, such as finding and isolating case-patients, quarantining close contacts, and enhanced infection control. The independent effectiveness of measures to "increase social distance" and wearing masks in public places requires further evaluation. Limited data exist on the effectiveness of providing health information to travelers. Entry screening of travelers through health declarations or thermal scanning at international borders had little documented effect on detecting SARS cases; exit screening appeared slightly more effective. The value of border screening in deterring travel by ill persons and in building public confidence remains unquantified. Interventions to control global epidemics should be based on expert advice from the World Health Organization and national authorities. In the case of SARS, interventions at a country's borders should not detract from efforts to identify and isolate infected persons within the country, monitor or quarantine their contacts, and strengthen infection control in healthcare settings.     

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。     

Evaluation of Border Entry Screening for Infectious Diseases in Humans

In response to the severe acute respiratory syndrome (SARS) pandemic of 2003 and the influenza pandemic of 2009, many countries instituted border measures as a means of stopping or slowing the spread of disease. The measures, usually consisting of a combination of border entry/exit screening, quarantine, isolation, and communications, were resource intensive, and modeling and observational studies indicate that border screening is not effective at detecting infectious persons. Moreover, border screening has high opportunity costs, financially and in terms of the use of scarce public health staff resources during a time of high need. We discuss the border-screening experiences with SARS and influenza and propose an approach to decision-making for future pandemics. We conclude that outbreak-associated communications for travelers at border entry points, together with effective communication with clinicians and more effective disease control measures in the community, may be a more effective approach to the international control of communicable diseases.     

HHS/CDC legal response to SARS outbreak

Before the severe acute respiratory syndrome (SARS) outbreak, the Centers for Disease Control and Prevention's (CDC) legal authority to apprehend, detain, or conditionally release persons was limited to seven listed diseases, not including SARS, and could only be changed using a two-step process: 1) executive order of the President of the United States on recommendation by the Secretary, U.S. Department of Health and Human Services (HHS), and 2) amendment to CDC quarantine regulations (42 CFR Parts 70 and 71). In April 2003, in response to the SARS outbreak, the federal executive branch acted rapidly to add SARS to the list of quarantinable communicable diseases. At the same time, HHS amended the regulations to streamline the process of adding future emerging infectious diseases. Since the emergence of SARS, CDC has increased legal preparedness for future public health emergencies by establishing a multistate teleconference program for public health lawyers and a Web-based clearinghouse of legal documents.     

Modeling control strategies of respiratory pathogens

Effectively controlling infectious diseases requires quantitative comparisons of quarantine, infection control precautions, case identification and isolation, and immunization interventions. We used contact network epidemiology to predict the effect of various control policies for a mildly contagious disease, such as severe acute respiratory syndrome, and a moderately contagious disease, such as smallpox. The success of an intervention depends on the transmissibility of the disease and the contact pattern between persons within a community. The model predicts that use of face masks and general vaccination will only moderately affect the spread of mildly contagious diseases. In contrast, quarantine and ring vaccination can prevent the spread of a wide spectrum of diseases. Contact network epidemiology can provide valuable quantitative input to public health decisionmaking, even before a pathogen is well characterized.     

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.     

Lack of SARS transmission among healthcare workers, United States

Healthcare workers accounted for a large proportion of persons with severe acute respiratory syndrome (SARS) during the worldwide epidemic of early 2003. We conducted an investigation of healthcare workers exposed to laboratory-confirmed SARS patients in the United States to evaluate infection-control practices and possible SARS-associated coronavirus (SARS-CoV) transmission. We identified 110 healthcare workers with exposure within droplet range (i.e., 3 feet) to six SARS-CoV-positive patients. Forty-five healthcare workers had exposure without any mask use, 72 had exposure without eye protection, and 40 reported direct skin-to-skin contact. Potential droplet- and aerosol-generating procedures were infrequent: 5% of healthcare workers manipulated a patient's airway, and 4% administered aerosolized medication. Despite numerous unprotected exposures, there was no serologic evidence of healthcare-related SARS-CoV transmission. Lack of transmission in the United States may be related to the relative absence of high-risk procedures or patients, factors that may place healthcare workers at higher risk for infection.     

Body temperature monitoring and SARS fever hotline, Taiwan

In Taiwan, a temperature-monitoring campaign and hotline for severe acute respiratory syndrome (SARS) fever were implemented in June 2003. Among 1,966 calls, fever was recorded in 19% (n = 378); 18 persons at high risk for SARS were identified. In a cross-sectional telephone survey, 95% (n = 1,060) of households knew about the campaign and 7 households reported fever.     

Healthcare worker seroconversion in SARS outbreak

Serum samples were obtained from healthcare workers 5 weeks after exposure to an outbreak of severe acute respiratory syndrome (SARS). A sensitive dot blot enzyme-linked immunosorbent assay, complemented by a specific neutralization test, shows that only persons in whom probable SARS was diagnosed had specific antibodies and suggests that subclinical SARS is not an important feature of the disease.