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GUIDELINES AND RECOMMENDATIONS Clinical Guidance on the Identification and Evaluation of Possible SARS-CoV Disease among Persons Presenting with Community-Acquired Illness Version 2 May 3, 2005

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This document provides guidance on the clinical evaluation and management of patients who present from the community with fever and/or respiratory illnesses. Recommendations supercede those in the Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS), available at www.cdc.gov/ncidod/sars/guidance/index.htm.

I. Introduction

Severe acute respiratory syndrome (SARS) is a recently recognized febrile severe lower respiratory illness that is caused by infection with a novel coronavirus, SARS-associated coronavirus (SARS-CoV). During the winter of 2002 through the spring of 2003, WHO received reports of >8,000 SARS cases and nearly 800 deaths. No one knows if SARS-CoV transmission will recur, but it is important to be prepared for that possibility. Early recognition of cases and application of appropriate infection control measures will be critical in controlling future outbreaks.

Many studies have been undertaken or are underway to evaluate whether there are specific laboratory and/or clinical parameters that can distinguish SARS-CoV disease from other febrile respiratory illnesses. Researchers are also working on the development of laboratory tests to improve diagnostic capabilities for SARS-CoV and other respiratory pathogens. To date, however, no specific clinical or laboratory findings can distinguish with certainty SARS-CoV disease from other respiratory illnesses rapidly enough to inform management decisions that must be made soon after the patient presents to the healthcare system. Therefore, early clinical recognition of SARS-CoV disease still relies on a combination of clinical and epidemiologic features.

II. Identification of Potential Cases of SARS-CoV Disease

The diagnosis of SARS-CoV disease and the implementation of control measures should be based on the risk of exposure. In the absence of any person-to-person transmission of SARS-CoV worldwide, the overall likelihood that a patient being evaluated for fever or respiratory illness has SARS-CoV disease will be exceedingly low unless there are both typical clinical findings and some accompanying epidemiologic evidence that raises the suspicion of exposure to SARS-CoV. Therefore, one approach in this setting would be to consider the diagnosis only for patients who require hospitalization for unexplained pneumonia and who have an epidemiologic history that raises the suspicion of exposure, such as recent travel to a previously SARS-affected area (or close contact with an ill person with such a travel history), employment as a healthcare worker with direct patient contact or as a worker in a laboratory that contains live SARS-CoV, or an epidemiologic link to a cluster of cases of unexplained pneumonia. Once person-to-person SARS-CoV transmission has been documented anywhere in the world, the positive predictive value of even early clinical symptoms (e.g., fever or lower respiratory symptoms in the absence of pneumonia), while still low, may be sufficiently high -- when combined with an epidemiologic link to settings in which SARS-CoV has been documented -- to lead clinicians to consider a diagnosis of SARS-CoV disease.

In that context, the guidance that follows should be considered in the evaluation and management of patients who present from the community with fever or lower respiratory illnesses. For more detailed guidance on infection control, see Supplement I in Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS).

III. Guidelines for Evaluation of SARS-CoV Disease among Persons Presenting with Community-Acquired Illness (Figures 1 and 2)

The following is an approach for the evaluation of possible SARS-CoV disease among persons presenting with community-acquired illness. As part of the evaluation, in addition to identification of suggestive clinical features, clinicians should routinely incorporate into the medical history questions that may provide epidemiologic clues to identify patients with SARS-CoV disease.

IV. Additional Considerations

In some settings, early recognition of SARS-CoV disease may require additional measures. The following guidance is provided to assist in the evaluation of patients in settings or with characteristics not detailed/outlined in Figures 1 and 2. These include SARS outbreaks in the surrounding community, management of patients who become ill while already in the hospital, workers from laboratories that contain live SARS-CoV, pediatric patients, the elderly, and persons with chronic underlying diseases.

A. Additional epidemiologic risk factors to consider in community outbreak settings

The risk factors that should trigger suspicion for SARS-CoV disease may vary depending on the level of SARS-CoV transmission occurring in the community. Specifically, as outbreaks become more widespread, the types of epidemiologic characteristics that are considered as risk factors for SARS-CoV disease should be broadened appropriately. Two examples are given below.

For persons with a high risk of exposure to SARS-CoV (e.g., persons previously identified through contact tracing as close contacts of a laboratory-confirmed case of SARS-CoV disease; persons who are epidemiologically linked to a laboratory-confirmed case of SARS-CoV disease), symptoms that should trigger the clinical algorithm should be expanded to include the presence of any of the following: sore throat, rhinorrhea, chills, rigors, myalgia, headache, diarrhea. For more details on the clinical features of SARS-CoV disease, see Figure 2, footnote 1.

C. Management of patients who acquire illness while in the hospital

This document focuses on the evaluation and management of patients who present from the community, although many of the same principles apply to hospitalized patients who develop nosocomial fever or lower respiratory symptoms. The diagnosis of nosocomial SARS-CoV disease may be particularly challenging, however, since many inpatients may have other reasons for developing nosocomial fever, lower respiratory symptoms, and pneumonia. Therefore, in hospitals known to have or suspected of having patients with SARS-CoV disease, clinicians and public health officials must be particularly vigilant about evaluating fever and respiratory illnesses among inpatients. Additional guidance on when to apply Figure 2 in the evaluation of patients who develop fever and/or respiratory illness while hospitalized is provided in Supplement C, Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS).

D. Laboratory workers

Breaks in technique in laboratories that contain live SARS-CoV can result in laboratory-acquired cases of SARS-CoV disease. Personnel working in laboratories that contain live SARS-CoV should report any febrile and/or lower respiratory illnesses to the supervisor, be evaluated for possible exposures, and be closely monitored for clinical features and course of illness. If laboratory workers with fever and/or lower respiratory illness are found to have an exposure to SARS-CoV, they should be managed according to the guidance in Figure 2. In addition, in an exposed laboratory worker, symptoms that should trigger the clinical algorithm in Figure 2 should be expanded to include the presence of any of the following: sore throat, rhinorrhea, chills, rigors, myalgia, headache, diarrhea (see Figure 2, footnote 1, for more information). Detailed information for persons who work in laboratories that contain live SARS-CoV is provided in Supplement F, Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS).

E. Considerations for the pediatric population

Typical symptoms of SARS-CoV disease may not always be present in elderly patients and those with underlying chronic illnesses, such as renal failure. Therefore, the diagnosis should be considered for almost any change in health status, even in the absence of typical clinical features of SARS-CoV disease, when such patients have epidemiologic risk factors for SARS-CoV disease (e.g., close contact with someone suspected to have SARS-CoV disease or exposure to a location [domestic or international] with documented or suspected recent transmission of SARS-CoV).

Figure 1. Algorithm for evaluation and management of patients requiring hospitalization for radiographically confirmed pneumonia, in the absence of person-to-person transmission of SARS-CoV in the world

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FOOTNOTES FOR FIGURE 1

¹ Or Acute Respiratory Distress Syndrome (ARDS) of unknown etiology

² Guidance for the management of community-acquired pneumonia is available from the Infectious Diseases Society of America (IDSA) and can be found online.

³ The 2003 SARS-CoV outbreak likely originated in mainland China, and neighboring areas such as Taiwan and Hong Kong are thought to be at higher risk due to the high volume of travelers from mainland China. Although less likely, SARS-CoV may also reappear from other previously affected areas. Therefore, clinicians should obtain a complete travel history. If clinicians have concerns about the possibility of SARS-CoV disease in a patient with a history of travel to other previously affected areas (e.g., while traveling abroad, had close contact with another person with pneumonia of unknown etiology or spent time in a hospital in which patients with acute respiratory disease were treated), they should contact the health department.

Figure 2: Algorithm for management of fever or respiratory symptoms when SARS-CoV person-to-person transmission is occurring in the world

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FOOTNOTES FOR FIGURE 2:

¹Clinical description of SARS-CoV disease and approach to treatment: Clinical judgment should be used to determine when symptoms trigger initiation of the algorithm in Figure 2. The early symptoms of SARS-CoV disease usually include fever, chills, rigors, myalgia, and headache. In some patients, myalgia and headache may precede the onset of fever by 12-24 hours. Respiratory symptoms often do not appear until 2-7 days after the onset of illness and most often include shortness of breath and/or dry cough. Diarrhea, sore throat, and rhinorrhea may also be early symptoms of SARS-CoV disease.

In the absence of fever, when screening patients for potential SARS-CoV disease, respiratory symptoms that would trigger the clinical algorithm are generally defined as lower respiratory tract symptoms (e.g., cough, shortness of breath, difficulty breathing). However, when screening patients who have a high risk of exposure to SARS-CoV (e.g., persons previously identified through contact tracing or self-identified as close contacts of a laboratory-confirmed case of SARS-CoV disease; persons who are epidemiologically linked to a laboratory-confirmed case of SARS-CoV disease), symptoms that should trigger the clinical algorithm should be expanded to include any of the following: sore throat, rhinorrhea, chills, rigors, myalgia, headache, diarrhea.

SARS-CoV testing may be considered as part of the initial work-up if there is a high level of suspicion for SARS-CoV disease based on exposure history. For additional details on specialized laboratory testing options available through the health department and the Laboratory Response Network (LRN), see CDC's SARS website.

⁴Alternative diagnosis:
An alternative diagnosis should be based only on laboratory tests with high positive-predictive value (e.g., blood culture, viral culture, Legionella urinary antigen, pleural fluid culture, transthoracic aspirate). In some settings, PCR testing for bacterial and viral pathogens can also be used to help establish alternative diagnoses. The presence of an alternative diagnosis does not necessarily rule out co-infection with SARS-CoV.

⁵Radiographic testing:
Chest CT may show evidence of an infiltrate before a chest radiograph (CXR). Therefore, a chest CT should be considered in patients with a strong epidemiologic link to a known case of SARS-CoV disease and a negative CXR 6 days after onset of symptoms. Alternatively, the patient should remain in SARS isolation, and the CXR should be repeated on day 9 after symptom onset.