severe acute respiratory syndrome (SARS), an infectious respiratory illness first reported in Asia and characterized by fever over 38° C (100.4° F), dry cough, and breathing difficulties, often accompanied by headache and body aches. It is believed to be caused by a strain of coronavirus, and severity ranges from mild illness to death. The infection appears to be spread by close contact with infected individuals, by inhalation of droplet nuclei containing the organism, or by contact with infected body fluids. ▪ OBSERVATIONS: The incubation period appears to range from 2 to 10 days. Early signs are rapid onset of fever (greater than 38° C or 100.4° F), headache, chills, rigors, and achiness. Upper respiratory symptoms (e.g., runny nose and sore throat) are unlikely. After a period of 3 to 7 days, lower respiratory symptoms, such as shortness of breath and a dry cough, develop. Nausea, vomiting, and diarrhea are seen in about 25% of cases. In the next 7 days, mild cases show an abatement of symptoms; about 20% of patients show a progressive respiratory deterioration with severe dyspnea, hypoxemia, and adult respiratory distress syndrome. More than half of these patients require mechanical ventilation. Patients with progressive deterioration are at high risk of respiratory failure and death. High initial levels of lactate dehydrogenase and absolute neutrophil counts and an age greater than 60 years appear to be predictors of severe disease and death. Diagnosis is made using clinical exam and clinical history using criteria established by the CDC. Early illness: Presence of two or more of the following features: fever (might be subjective), chills, rigors, myalgia, headache, diarrhea, sore throat, or rhinorrhea. Mild to moderate illness: History of fever equal to 38° C (100.4° F) and one or more symptoms of lower respiratory tract illness (cough, dyspnea, and shortness of breath). Severe illness: Radiographic evidence of pulmonary infiltrates or ARDS or autopsy findings consistent with pathological conditions of pneumonia or ARDS without identifiable cause and no alternative diagnosis. Possible exposure: Travel to location with recent transmission of SARS up to 10 days before symptom appearance and/or close contact with a person with respiratory illness and history of travel. Likely exposure: Close contact with person with confirmed SARS and/or close contact with a person with respiratory illness for whom a chain of transmission can be linked to a confirmed case of SARS 10 days before appearance of symptoms. Laboratory tests to detect SARS-CoV are being refined so lab criteria are changing. The following are general criteria for lab confirmation: detection of serum antibody to SARS-CoV by a test validated by CDC (e.g., enzyme immunoassay), or isolation in cell culture of SARS-CoV, or detection of SARS-CoV RNA by a reverse transcription polymerase chain reaction test validated by CDC and confirmed in a reference laboratory. ▪ INTERVENTIONS: Immediate isolation (droplet, contact, and respiratory) is required for anyone suspected of having SARS. All suspected cases should be reported to the local public health authorities/state health department and the CDC. Treatment is largely supportive and includes rest, humidification, hydration, nutritional support, and oxygen. Analgesics are used for pain. Tracheostomy and/or mechanical ventilation may be indicated to improve respiratory function. There are indications that pulsed steroids may shorten course of disease. ▪ PATIENT CARE CONSIDERATIONS: Since 2004, no known cases of SARS have been reported anywhere in the world.
