Severe Acute Respiratory Syndrome (SARS)

Travel to endemic area within 10 days before symptom onset, including mainland China, Hong Kong, Singapore, Taiwan, Vietnam, and Toronto

Persistent fever, dry cough, dyspnea in most cases

Mortality: as high as 14% in clinically diagnosed cases

SARS is an atypical pneumonia that affects all age groups

Incubation period is 2–7 days; it can be spread to contacts of affected patients for 10 days. Mean time from onset of clinical symptoms to hospital admission is 3–5 days

In all clinical cases, persistent fever is present; chills/rigor, cough, shortness of breath, rales, and rhonchi are the rule

Headache, myalgias, and sore throat are common

Watery diarrhea occurs in subset of patients

Elderly patients may report malaise and delirium, without fever

Serologic tests are available, but seroconversion may not occur until 3 weeks after the onset of symptoms

Conventional reverse transcriptase polymerase chain reaction (RT-PCR)

• Detection rates for the virus are generally low in the first week of illness

• Urine, nasopharyngeal aspirate, and stool specimens are positive in 42%, 68%, and 97%, respectively, on day 14 of illness

Leukopenia (particularly lymphopenia) and low-grade disseminated intravascular coagulation are common

Modest elevations of alanine aminotransferase (ALT) and creatine kinase are frequently seen

Arterial oxygen saturation < 95% with associated nonspecific pulmonary infiltrates is evident in 80% of affected individuals

A high-resolution CT scan is abnormal in 67% of patients with initially normal chest radiographs

No specific treatment

Supportive therapy is mainstay

The following agents were used during the 2003 epidemic, but their efficacy remains inconclusive

• Ribavirin (400–600 mg/day and 4 g/day)

• Lopinavir/ritonavir (400 mg/100 mg)

• Interferon type I

• IVIG

• Systemic corticosteroids