Severe Acute Respiratory Syndrome (SARS)

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Transcript Severe Acute Respiratory Syndrome (SARS)

Severe Acute Respiratory Syndrome (SARS) and

Preparedness

for Biological Emergencies 27 April 2004

Jeffrey S. Duchin, M.D

Immunization Section, County Division of Allergy and Infectious Diseases,

.

Chief, Communicable Disease Control, Epidemiology and Public Health - Seattle & King University of Washington

Supplemental Slides

• The following slides contain supplemental information.

Draft-Algorithm to Work Up and Isolate Symptomatic Persons who may have been Exposed to SARS Fever or Respiratory Illness 1 in Adults Who May Have Been Exposed to SARS Begin SARS isolation precautions, initiate preliminary work-up; notify Health Department 2 CXR No Radiographic Evidence of Pneumonia Alternative diagnosis confirmed 3 No Alternative Diagnosis Consider D/C SARS isolation precautions 5 Continue SARS isolation and re-evaluate 72 hours after initial evaluation Persistent fever or unresolving respiratory symptoms Symptoms improve or resolve Perform SARS test; continue SARS isolation for additional 72 hr. At end of the 72 hrs, repeat clinical evaluation including CXR + CXR No radiogrpahic evidence of pneumonia Use algorithm for CXR + cases Consider D/C SARS isolation precautions 5

Draft- Algorithm to Work Up & Isolate Symptomatic Persons who may have been Exposed to SARS Fever or Respiratory Illness 1 in Adults Who May Have Been Exposed to SARS Begin SARS isolation precautions, initiate preliminary work-up; notify Health Department 2 Radiographic Evidence of Pneumonia Perform SARS testing Laboratory evidence of SARS-CoV or No alternative diagnosis Continue SARS isolation until 10 days following resolution of fever given respiratory symptoms are absent or resolving Alternative diagnosis confirmed Consider D/C SARS isolation precautions

• • • •

Using Alternative Diagnosis to Rule Out” SARS Based on test with high positive predictive value Clinical course consistent No evidence of clustering No strong epidemiologic lin

Severe Acute Respiratory Syndrome

Symptoms and Signs

Symptom Rales/Rhonchi Hypoxia Range (%) 38-90 60-83 Sign Fever Cough Dyspnea Chills/Rigor Myalgias Headache Diarrhea Nausea/Vomiting (Rhinorrhea) (Sore Throat) Range (%) 95-100 57-100 20-100 73-90 20-83 20-70 10-67 10-24 5-25 5-25

Severe Acute Respiratory Syndrome

Laboratory Findings

Finding Leukopenia* Lymphopenia Thrombocytopenia* Prolonged aPTT Increased ALT Increased LDH Increased CPK Range (%) 17-34 70-95 30-50 40-60 20-30 (2-6X ULN) 70-94 30-40 (up to 3000 IU/L) *Total WBC count normal or decreased; absolute lymphocyte count may be decreased early in course. At the peak of respiratory illness, approximately 50% of patients have leukopenia and thrombocytopenia or low-normal platelet counts.

Severe Acute Respiratory Syndrome

Chest Radiograph and CT

• Up to 30% normal at presentation • Infiltrates subsequently develop in nearly all laboratory confirmed cases – 66% by day 3; 97% by day 7; 100% by day 10 • A “substantial proportion” of cases show early focal interstitial infiltrates progressing to more generalized, patchy interstitial infiltrates • Focal consolidation • HRCT: Ground-glass opacification with or without thickening of the intra-lobular or interlobular interstitium +/- consolidation Wong. Radiology 2003;228:401-6; Wang. Proceedings of International Science Symposium on SARS. Beijing, China, 2003; Xue. Chin Med J 2003;116:819-822; Zhao. J Med Microbiol 2003;52:715-20. Rainer. BMJ 2003;326:1354-8.

SARS & Other Public Health Emergencies

Diagnostic Testing: Key Concepts

• Be familiar with the appropriate diagnostic/laboratory tests • Interpretation of results of new tests and implications for patient management • Special procedures for obtaining and submitting specimens • Biosafety considerations: precautions to protect laboratory workers

Severe Acute Respiratory Syndrome

CDC Case Definition: Close Contact

• Close contact is defined as having cared for or lived with a person known to have SARS, or having a high likelihood of direct contact with respiratory secretions and/or body fluids of a patient known to have SARS during encounters with the patient or through contact with materials contaminated by the patient.

• Examples of close contact include kissing or embracing, sharing eating or drinking utensils, close conversation (<3 feet), physical examination, and any other direct physical contact between persons. • Close contact does not include such activities such as walking by a person or sitting across a waiting room or office for a brief period of time.

Severe Acute Respiratory Syndrome

What to Do Now:

Absence of SARS Activity Worldwide but in the presence of avian influenza H5N1 • Identify all patients hospitalized with pneumonia and one of the following risk factors: • Travel to mainland China, Hong Kong, or Taiwan, or close contact with an ill person with a history of recent travel to one of these areas,

OR

• Travel within 10 days of symptom onset to a country with H5N1 avian influenza in poultry or humans • Employment in an occupation associated with a risk for SARS-CoV exposure (e.g., health care worker with direct patient contact; worker in a laboratory that contains live SARS-CoV),

OR

• Part of a cluster of cases of atypical pneumonia without an alternative diagnosis.

• Report to public health all cases answering yes to one of the above, and clusters of unexplained pneumonia

Severe Acute Respiratory Syndrome

What to Do Now

: Absence of SARS Activity Worldwide • For patients with pneumonia or ARDS who have recently traveled to Guangdong Province, China, diagnostic testing for SARS-CoV should be performed immediately. • For others answering yes to one of the screening questions: – Droplet precautions (Consider SARS isolation precautions if patient thought to be at high-risk after consultation with Public Health) – Evaluate for alternative diagnosis – Look for evidence of clustering – Reassess after 72 hours and consider SARS testing if no alternative diagnosis and evidence of clustering or other reason to consider patient at high risk for SARS

Severe Acute Respiratory Syndrome

When to Have a High Suspicion for SARS

In the Absence of SARS Activity Worldwide • Situations in which a high suspicion for SARS is appropriate • The patient is part of a cluster of two or more healthcare workers who 1) are hospitalized for CXR-confirmed pneumonia or ARDS 2) had direct patient contact, 3) have worked in the same facility, and 4) had illness onset within same 10-day period, OR • The patient has 1) no alternate diagnosis that could explain the illness, 2) recently returned from a previously SARS affected area, and 3) either had close contact with someone hospitalized for a respiratory infection or visited a hospital while in the previously affected area and within 10 days of their illness onset .

Evaluation & management of patients requiring hospitalization for radiographically confirmed pneumonia, in the absence of person-to person transmission of SARS-CoV in the world