[Study on the correlation between positive rates of SARS RNA in clinical confirmed SARS patients and the appearance of RNA in relation to the development of the disease].
OBJECTIVE
To study the correlation between positive rates of RNA in clinical confirmed severe acute respiratory syndrome (SARS) patients and its appearance in relation to the development of the disease in order to provide scientific basis for early diagnosis, effective prevention and treatment of the disease.


METHODS
One-step reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify the SARS RNA in the clinical specimens from different courses of the disease. The representative amplicons were then sequenced. Chi-square for trend test was performed to study the correlation between positive rates of RT-PCR and at different periods after the onset of the disease.


RESULTS
The fragments amplified from the sputum specimens of SARS patients were shown to share 100% homology with the published SARS-associated coronavirus. Of the different clinical specimens, positive rate in the stools appeared to be the highest (21.55%). Chi-square for trend test revealed that the positive rates of stools and sputa of SARS patients decreased with the development of the disease (chi(2) for trend = 12.55 and 16.408, P = 0.0004 and P = 0.000 05 respectively).


CONCLUSIONS
One-step RT-PCR proved to be an effective method for the detection of SARS-associated coronavirus from clinical specimens. Data as indicated that the positive rates of SARS coronavirus were decreasing in SARS patients along with the disease progression.
Tang
Fang
F
Institute of Microbiology and Epidemiology, Beijing 100071, China.
Liu
Wei
W
Zhang
Pan-he
PH
Zhao
Qiu-min
QM
Zhan
Lin
L
Zuo
Shu-qing
SQ
Wu
Xiao-ming
XM
Yang
Hong
H
Fang
Li-qun
LQ
Wei
Mao-ti
MT
Wang
Hong-wei
HW
Cao
Wu-chun
WC
D000293:Adolescent; D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D002681:China; D018450:Disease Progression; D005243:Feces / Q000821:virology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009093:Mucus / Q000821:virology; D012367:RNA, Viral / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000302:isolation & purification; D045169:Severe Acute Respiratory Syndrome / Q000473:pathology / Q000821:virology*
D012367:RNA, Viral