Rapid laboratory diagnosis mostly relied on nucleic acid amplification assays, using the SARS-CoV open reading frame 1b or nucleoprotein gene as targets in the detection of respiratory specimens, stool, urine, blood, and lung tissue (Chan et al., 2004b, Lau et al., 2005a, Poon et al., 2003, Poon et al., 2004 and Poon et
al., 2005b). Diagnosis A-1210477 supplier rarely relied on enzyme immunoassay (EIA) for viral nucleocapsid protein antigen detection on patients’ sera (Che et al., 2004a, Che et al., 2004b and Lau et al., 2004c). The nucleoprotein (NP) gene and protein were chosen as targets for RT-PCR and EIA because NP is the most abundantly expressed mRNA and
protein in the infected cells, and should therefore give a higher sensitivity. Real-time quantitative RT-PCR of nasopharyngeal aspirates was found to have a sensitivity of 80%, even if the specimen was collected within the first 5 days of symptom onset (Poon et al., 2004). The shedding of virus correlated with the clinical course. Among 14 SARS patients with serial collection PCI-32765 mouse of nasopharyngeal aspirates on days 5, 10 and 15 after symptom onset, viral loads peaked on around day 10, with an inverted V pattern (Peiris et al., 2003a). In additional to respiratory and stool samples (Cheng et al., 2004a), quantitative second measurement of viral loads were also performed on other specimens including serum, urine, and saliva (Hung et al., 2009 and Wang et al., 2004b). Detection of virus by RT-PCR could persist for up to 51 days in lung tissue (Farcas et al., 2005). Because no therapy was
proven effective in randomized control trials, supportive treatment played an important role in the treatment of SARS. Since the etiological agent of SARS was unknown during the initial phase of the epidemic, patients were given empirical antibiotics for the treatment of community-acquired pneumonia, with coverage of both typical and atypical bacterial pathogens (So et al., 2003). Broad-spectrum antibiotics were indicated in patients who developed nosocomial bacteremia, catheter-related sepsis, and nosocomial pneumonia due to Escherichia coli, Klebsiella pneumoniae, and Stenotrophomonas maltophilia ( Peiris et al., 2003a). Effective antiviral agents are needed to control viral replication, and hence inflammation and tissue damage, as the high viral load was positively correlated with the development of organ failure and death in a subsequent study ( Hung et al., 2009).