Abstract & Commentary
Source: Centers for Disease Control and Prevention. Update: Severe acute respiratory syndrome—United States, 2003. Morb Mortal Wkly Rep MMWR 2003;52:357-360.
As of April 23, 2003, a total of 4288 cases of severe acute respiratory syndrome (SARS) in 25 countries had been reported to the World Health Organization. Internationally, there had been 251 deaths, yielding a case-fatality rate of 6%. In the United States, there were 245 cases of SARS in 37 states. Thirty-nine cases were classified as "probable," and 206 as "suspect." Tests for a SARS-associated novel coronavirus (SARS-CoV) were positive in about half of probable cases and in none of the suspect cases in the United States, but test results were available for fewer than one-fifth of cases as of the end of April 2003.
All SARS cases reported in the United States involved patients who had traveled to areas endemic for SARS or had come in close contact with a SARS case. Ninety-one percent of patients had traveled to mainland China, Hong Kong, Singapore, Hanoi, or Toronto. A few cases were health care workers who provided care to a SARS patient or household contacts of a SARS patient. Thirty-seven percent of all U.S. SARS cases, and 69% of probable cases, required hospitalization. Two patients required mechanical intubation.
Commentary by David J. Karras, MD, FAAEM, FACEP
The Centers for Disease Control and Prevention updated its interim case definition for SARS on April 20, 2003. A suspect case is a patient with a respiratory illness of unknown etiology who has a temperature greater than 100.4°F, one or more signs of respiratory illness (cough, dyspnea, or hypoxia), and either traveled to an endemic region within 10 days of symptom onset or had close contact with a suspected SARS case. A probable case of SARS is defined as one meeting all these criteria, and having either radiographic evidence of pneumonia or respiratory distress syndrome, or autopsy findings consistent with respiratory distress syndrome for which no other cause is identified. As of late April 2003, areas considered at risk for transmission of SARS were mainland China, Hong Kong, Hanoi, Singapore, and Toronto.1
While the media have focused on the fact that there have been more than 245 reported cases of SARS in the United States, it is very important to note that the SARS-CoV test has so far been negative in each of the suspect cases and in about half of the three dozen probable cases.
The large number of pending tests makes it dangerous to extrapolate this data, but it appears that fewer than 10% of all reported SARS cases in the United States ultimately will be diagnosed with the illness. The current case definition is appropriately lax at this time, and any febrile patient with respiratory complaints having traveled to a SARS-endemic region is presently considered to be a suspect case.
Patients meeting SARS criteria who present to the ED should be identified by the triage nurse and immediately segregated in respiratory isolation rooms. Health care workers should employ airborne infection precautions (i.e., N-95 respirators), contact precautions (i.e., gowns and gloves), as well as standard precautions (i.e., hand washing). Eye protection also is recommended.2
Dr. Karras, Associate Professor of Emergency Medicine, Department of Emergency Medicine Temple University School of Medicine, Director of Emergency Medicine Research, Temple University Hospital, Philadelphia, PA, is on the Editorial Board of Emergency Medicine Alert.
1. Centers for Disease Control and Prevention. Updated interim U.S. case definition of severe acute respiratory syndrome (SARS). www.cdc.gov/ncidod/sars/casedefinition.htm. (Accessed April 28, 2003.)
2. Centers for Disease Control and Prevention. Update: Outbreak of severe acute respiratory syndrome—worldwide, 2003. Morb Mortal Wkly Rep MMWR 2003;52:241-248.