Laboratory detection on severe acute respiratory syndrome / 中华检验医学杂志

ABSTRACT

Objective To provide scientific evidence to identify and confirm severe acute respiratory syndrome (SARS) by laboratory detection.Methods Multiple clinical specimens were collected serially and systematically from the 4 suspected SARS patients, which occurred between Dec.2003 to Jan.2004 in Guangdong Province. The samples were tested by serologic and molecular methods.Results IgM or IgG antibodies against SARS-CoV were detectable after 6—8 days of the onset in four patients. The four-fold or greater rising in antibodies was clearly detected in three of the four patients, while the fourth patient’s seroconversion was from negative to positive. The results analysed by enzyme-linked immunosorbent assay( ELISA), immunoflourescence assay (IFA), and neutralization test were highly correlated. SARS-CoV RNA was just detected in 3 throat swab specimens from case 1 by real-time PCR. M, N and S genes were amplified by reverse transcriptase polymerase chain reaction (RT-PCR) from the positive samples. Sequencing results showed that they were SARS-CoV gene segments, and most closely matched SARS-CoV gene sequences were isolated from civet cats in Guangdong Province. Nevertheless, SARS-CoV was not isolated from any samples of the 4 patients.Conclusion Based on these results, the 4 reported cases were laboratorily confirmed as SARS cases.