Revised U.S. surveillance case definition for severe acute respiratory syndrome (SARS) and update on SARS cases--United States and worldwide, December 2003

During the 2003 epidemic of severe acute respiratory syndrome (SARS), CDC and the Council of State and Territorial Epidemiologists (CSTE) developed surveillance criteria to identify persons with SARS. The surveillance case definition changed throughout the epidemic as understanding of the clinical, laboratory, and transmission characteristics of SARS-associated coronavirus (SARS-CoV) increased. On June 26, CSTE adopted a position statement to add SARS-CoV disease to the National Notifiable Disease Surveillance System (NNDSS). The position statement included criteria for defining a SARS case for national reporting. On November 3, CSTE issued a new interim position statement with a revised SARS case definition. This report summarizes the new U.S. surveillance case definition for SARS and updates reported cases of SARS worldwide and in the United States.     

SARS clinical features, United States, 2003

We compared the clinical features of 8 U.S. case-patients with laboratory-confirmed severe acute respiratory syndrome (SARS) to 65 controls who tested negative for SARS coronavirus (SARS-CoV) infection. Shortness of breath, vomiting, diarrhea, progressive bilateral infiltrates on chest radiograph, and need for supplemental oxygen were significantly associated with confirmed SARS-CoV infection.     

Updated interim surveillance case definition for severe acute respiratory syndrome (SARS)--United States,April 29, 2003

CDC's interim surveillance case definition for severe acute respiratory syndrome (SARS) has been updated to include laboratory criteria for evidence of infection with the SARS-associated coronavirus (SARS-CoV) (Figure, Box). In addition, clinical criteria have been revised to reflect the possible spectrum of respiratory illness associated with SARS-CoV. Epidemiologic criteria have been retained. The majority of U.S. cases of SARS continue to be associated with travel, with only limited secondary spread to household members or health-care providers.     

Detection of SARS coronavirus in patients with suspected SARS

Cases of severe acute respiratory syndrome (SARS) were investigated for SARS coronavirus (SARS-CoV) through RNA tests, serologic response, and viral culture. Of 537 specimens from patients in whom SARS was clinically diagnosed, 332 (60%) had SARS-CoV RNA in one or more clinical specimens, compared with 1 (0.3%) of 332 samples from controls. Of 417 patients with clinical SARS from whom paired serum samples were available, 92% had an antibody response. Rates of viral RNA positivity increased progressively and peaked at day 11 after onset of illness. Although viral RNA remained detectable in respiratory secretions and stool and urine specimens for >30 days in some patients, virus could not be cultured after week 3 of illness. Nasopharyngeal aspirates, throat swabs, or sputum samples were the most useful clinical specimens in the first 5 days of illness, but later in the illness viral RNA could be detected more readily in stool specimens.     

Update: outbreak of severe acute respiratory syndrome--worldwide, 2003

CDC and the World Health Qrganization (WHO) are continuing to investigate the multicountry outbreak of unexplained atypical pneumonia referred to as severe acute respiratory syndrome (SARS). Pending development of confirmatory laboratory testing capacity, CDC's interim suspected SARS case definition is based on clinical criteria and epidemiologic linkage to other SARS cases or areas with community transmission of SARS. This case definition will be updated periodically as new information becomes available. Epidemiologic and laboratory investigations of SARS are ongoing. As of April 2, 2003, a total of 2,223 suspected and/or probable SARS cases have been reported to WHO from 16 countries, including the United States. The reported SARS cases include 78 deaths (case-fatality proportion: 3.5%). This report summarizes SARS cases among U.S. residents and surveillance and prevention activities in the United States.     

Coronavirus Disease Case Definitions,Diagnostic Testing Criteria,and Surveillance in 25 Countries with Highest Reported Case Counts

We compared case definitions for suspected, probable, and confirmed coronavirus disease (COVID-19), as well as diagnostic testing criteria, used in the 25 countries with the highest reported case counts as of October 1, 2020. Of the identified countries, 56% followed World Health Organization (WHO) recommendations for using a combination of clinical and epidemiologic criteria as part of the suspected case definition. A total of 75% of identified countries followed WHO recommendations on using clinical, epidemiologic, and diagnostic criteria for probable cases; 72% followed WHO recommendations to use PCR testing to confirm COVID-19. Finally, 64% of countries used testing eligibility criteria at least as permissive as WHO. We observed marked heterogeneity in testing eligibility requirements and in how countries define a COVID-19 case. This heterogeneity affects the ability to compare case counts, transmission, and vaccine effectiveness, as well as estimates derived from case surveillance data across countries.     

SARS-CoV特异性抗体产生规律的初步研究

目的 研究严重急性呼吸综合征(SARS)患者感染后体内病毒特异性抗体产生规律。方法 收集临床确诊为SARS患者的血清和非SARS人群血清标本,用IgM捕获法、间接法和抗原夹心法三种不同方法检测抗SARS病毒特异性IgM、IgG和总抗体。结果 检测146份临床诊断为SARS的患者不同发病时间血清标本,三种抗体阳性率分别为61.64％、53.43％和69.86％;SARS病毒特异性IgM、IgG抗体的最早检出时间分别在发病第7天和第12天,特异性IgM抗体最短在发病后42天消失。三种方法检测70份甲型肝炎患者血清时,均有2份非特异阳性反应,检测127份其他病种血清均阴性,1例密切接触SARS患者的医务人员SARS特异性IgG抗体和总抗体均阳性,三种检测方法均不受类风湿因子影响。结论 与其他病毒感染相比,SARS病毒感染者的特异性IgM抗体检出时间较晚,且持续时间较短;三种检测方法均有较好的特异性和敏感性,可用于SARS的流行病学调查和临床诊断的确认和补充,但不适用于SARS的早期诊断。     

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.     

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-associated coronavirus transmission, United States

To better assess the risk for transmission of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV), we obtained serial specimens and clinical and exposure data from seven confirmed U.S. SARS patients and their 10 household contacts. SARS-CoV was detected in a day-14 sputum specimen from one case-patient and in five stool specimens from two case-patients. In one case-patient, SARS-CoV persisted in stool for at least 26 days after symptom onset. The highest amounts of virus were in the day-14 sputum sample and a day-14 stool sample. Residual respiratory symptoms were still present in recovered SARS case-patients 2 months after illness onset. Possible transmission of SARS-CoV occurred in one household contact, but this person had also traveled to a SARS-affected area. The data suggest that SARS-CoV is not always transmitted efficiently. Routine collection and testing of stool and sputum specimens of probable SARS case-patients may help the early detection of SARS-CoV infection.     

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.     

Challenges faced by hospital healthcare workers in using a syndrome-based surveillance system during the 2003 outbreak of severe acute respiratory syndrome in Taiwan.

Because the severe acute respiratory syndrome (SARS) outbreak in Taiwan in 2003 was worsened by hospital infections, we analyzed 229 questionnaires (84.8% of 270 sent) completed by surveyed healthcare workers who cared for patients with SARS in 3 types of hospitals, to identify surveillance problems. Atypical clinical presentation was the most often reported problem, regardless of hospital type, which strongly indicates that more timely syndromic surveillance was needed.     

Laboratory-based surveillance of nontyphoidal Salmonella infections in China

Foodborne infections are an important public health problem in China. In 2008, we conducted surveillance for laboratory-confirmed nontyphoidal Salmonella to monitor trends for this infection in China and to build capacity for rapid detection and response to foodborne outbreaks. Salmonella isolates from patients with diarrhea were sent from hospitals to local public health laboratories for confirmation, serotyping, and antimicrobial susceptibility testing. A total of 126 hospitals in 44 cities and counties from 8 provinces provided isolates and epidemiologic data for analysis. Of 23,140 stool specimens submitted to clinical laboratories, 662 (3%) grew Salmonella enterica. Salmonella were most commonly detected between April and October. The median age of infected patients was 27 years; 34% of infections occurred in patients <5 years old. Of the 662 isolates, we found 73 serotypes, of which serotype Enteritidis (31%) and serotype Typhimurium (26%) were the most common. The prevalence of resistance was high for clinically important antimicrobial agents, including ampicillin (41%) and ciprofloxacin (6%). More than 60% of isolates, including 35% of all Typhimurium, were resistant to three or more antimicrobial agents. In this first multiprovince surveillance report of laboratory-confirmed Salmonella infections in China, we found that Enteritidis and Typhimurium are the most common serotypes and that efforts to reduce antimicrobial resistance among Salmonella in China are needed. Although no outbreaks were detected using this system, efforts to improve this system's capacity to do so are underway.     

SARS transmission in Vietnam outside of the health-care setting

To evaluate the risk of transmission of SARS coronavirus outside of the health-care setting, close household and community contacts of laboratory-confirmed SARS cases were identified and followed up for clinical and laboratory evidence of SARS infection. Individual- and household-level risk factors for transmission were investigated. Nine persons with serological evidence of SARS infection were identified amongst 212 close contacts of 45 laboratory-confirmed SARS cases (secondary attack rate 4.2%, 95% CI 1.5-7). In this cohort, the average number of secondary infections caused by a single infectious case was 0.2. Two community contacts with laboratory evidence of SARS coronavirus infection had mild or sub-clinical infection, representing 3% (2/65) of Vietnamese SARS cases. There was no evidence of transmission of infection before symptom onset. Physically caring for a symptomatic laboratory-confirmed SARS case was the only independent risk factor for SARS transmission (OR 5.78, 95% CI 1.23-24.24).     

101例严重急性呼吸综合征患者粪便中SARS冠状病毒RNA的检测

目的　研究严重急性呼吸综合征 (SARS)患者粪便中排出SARS冠状病毒 (SARS CoV)RNA的情况。方法　采用荧光定量聚合酶链反应法 (FQ PCR)检测 10 1例病程为 10～ 5 5d的SARS患者、2 7例非SARS患者和 4 0 0名健康体检人群粪便中SARS CoVRNA。结果　 10 1例SARS患者的粪便标本中 5 8例 (5 7 4 % )SARS CoVRNA阳性 ;2 7例非SARS患者和 4 0 0名健康体检人群的粪便标本均为阴性。SARS患者发病后 10～ 19、2 0～ 2 9、30～ 39和 4 0～ 5 5d ,粪便中SARS CoVRNA阳性率分别为 10 0 % (8/ 8)、6 7 7% (2 1/ 31)、4 7 4 % (2 7/ 5 7)和 4 0 0 % (2 / 5 )。粪便中SARS CoVRNA载量对数值分别为 6 0 6± 2 0 5、4 5 1± 1 2 3、3 82± 1 4 4和 3 5 7± 1 2 5。结论　SARS患者急性期粪便中SARS CoVRNA阳性率和载量对数值最高 ,且随病程延长而下降     

Gaps remain in China's ability to detect emerging infectious diseases despite advances since the onset of SARS and avian flu

Early detection of emerging infections in China is critical to the health of the 1.3 billion Chinese people and to the world. China's surveillance system for endemic infectious diseases has improved greatly since 2003, but the country's ability to conduct surveillance for laboratory-confirmed infections remains underdeveloped. This is dangerous for China, the world's most populous country, which has been the focus of global attention since outbreaks of severe acute respiratory syndrome (SARS) and avian influenza. We describe China's public health advances since the 2003 SARS outbreak and conclude that China must now invest far more in pathogen-based surveillance. An enhanced disease-detection system in China will help prevent and contain outbreaks before they cause substantial illness and death in China and other countries.     

Update: severe acute respiratory syndrome--United States,June 11, 2003

CDC continues to work with state and local health departments, the World Health Organization (WHO), and other partners to investigate cases of severe acute respiratory syndrome (SARS). This report updates SARS cases reported worldwide and in the United States, and describes the eighth probable U.S. SARS case with laboratory evidence of SARS-associated coronavirus (SARS-CoV) infection.     

SARS恢复期患者血液与排泄物中SARS-CoV RNA的检测

目的应用巢式逆转录聚合酶链反应(RT—PCR)检测严重急性呼吸综合征(SAILS)恢复期患者血液与排泄物中的病毒RNA。方法对连续3次收集的23例确诊SARS恢复期(病程≥21天)患者的血、尿、痰、粪便标本进行核酸提取，设计特异性内外引物，使用巢式RT—PcR的方法进行病毒RNA检测。结果通过巢式RT—PCR，共检测到6份阳性标本，其中粪便标本中检测到4份，检出率为5．8％；痰标本中检测到2份，检出率为2．9％。在尿液和血液标本中未检测到病毒．RNA。结论个别SARS恢复期患者排泄物中有SARS病毒RNA存在，因此对恢复期患者的排泄物应慎重处理，对其引起SARS的再次传播的危险性需要进一步评估。     

Update: severe acute respiratory syndrome--United States,May 28, 2003

CDC continues to work with state and local health departments, the World Health Organization (WHO), and other partners to investigate cases of severe acute respiratory syndrome (SARS). This report updates SARS cases reported worldwide and in the United States and reports a seventh laboratory-confirmed U.S. case.     

广州军队医院SARS病例流行病学特点分析

目的分析广州市军队医院收治的SARS病例的临床流行病学特点,为防治对策和措施提供科学依据.方法采用查阅病历、面对面访谈、电话调查及现场调查相结合的方法,收集SARS病例流行病学和临床诊治资料,利用SPSS软件10.0分析SARS病例分布特点和恢复期血清IgG抗体情况.结果 147例SARS临床诊断病例中,109例分布于广州市各个辖区,有38例来自外地;发病年龄主要集中在18～48岁;37例属于聚集性病例,49例有明确的接触史(33.33%);死亡7例.检测90例恢复期血清特异性IgG抗体,阳性46例,有同类病例接触史者血清抗体阳性率为85.29%,高于无接触史者的27.66%(P＜0.001).发热时间≥7d者血清抗体阳性率为68.89%,高于发热＜7d者的30.95%(P＜0.001).结论广州军队医院收治的SARS病例流行病学特点与广东省疫情态势基本一致;流行病学接触史加血清学结果有助于病例确诊;存在未明的传染来源或传播方式.