Rapid Diagnosis of a Coronavirus Associated with Severe Acute Respiratory Syndrome (SARS)

Abstract

Severe acute respiratory syndrome (SARS) is a recently emerged disease associated with pneumonia in infected patients (1). The disease is unusual in its severity, and patients suffering from this disease do not respond to empirical antimicrobial treatment for acute community-acquired typical or atypical pneumonia (2). By the end of March 2003, a cumulative total of 1622 cases and 58 deaths had been reported from 13 countries (3). The disease is highly infectious, and attach rates >56% have been reported in healthcare workers caring for SARS patients (2). Recently, we identified a novel virus in the family Coronaviridae in SARS patients (4). Of patients from whom paired acute and convalescent sera were available, all had seroconverted or had a greater than fourfold increase in antibody titer to this novel virus (4), suggesting that it plays an important role in the etiology of SARS. Thus, the establishment of a rapid noninvasive test for this virus is a high priority for monitoring and control of this disease. Here, we report a real-time quantitative PCR assay to detect this virus in clinical specimens. Patients with a clinical diagnosis of SARS and admitted in two hospitals in Hong Kong between February 26, 2003, and March 26, 2003, were considered for this study. Inclusion criteria were a fever of 38 °C or higher, cough or shortness of breath, new pulmonary infiltrate(s) on chest radiographs, and either a history of exposure to a patient with SARS or absence of response to empirical antimicrobial coverage for typical and atypical pneumonia. Samples were collected with informed consent. In total, 29 SARS patients with paired sera and nasopharyngeal aspirate (NPA) samples were available for the study. The diagnosis of SARS was confirmed in all patients by the presence of antibodies against the novel coronavirus in the serum (4). The …