Using patient-collected clinical samples and sera to detect and quantify the severe acute respiratory syndrome coronavirus (SARS-CoV)

Abstract

Background. Severe acute respiratory syndrome (SARS) caused a large outbreak of pneumonia in Beijing, China, in 2003. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect and quantify SARS-CoV in 934 sera and self-collected throat washes and fecal samples from 271 patients with laboratory-confirmed SARS managed at a single institution. Results. SARS-CoV detection rates in sera were highest in the first 9 days of illness, whereas detection was highest in throat washes 5-14 days after onset of symptoms. The highest SARS-CoV RT-PCR rates (70.4-86.3%) and viral loads (log10 4.5-6.1) were seen in fecal samples collected 2-4 weeks after the onset of clinical illness. Fecal samples were frequently SARS-CoV RT-PCR positive beyond 40 days, and occasional sera still had SARS-CoV detected after 3 weeks of illness. Conclusion. In the context of an extensive outbreak with major pressure on hospital resources, patient self-collected samples are an alternative to nasopharyngeal aspirates for laboratory confirmation of SARS-CoV infection. © 2007 He et al; licensee BioMed Central Ltd.