Detection of severe acute respiratory syndrome coronavirus RNA in plasma during the course of infection.

Wang, Wei-Kung; Fang, Chi-Tai; Chen, Hui-Ling; Yang, Chao-Fu; Chen, Yee-Chun; Chen, Mei-Ling; Chen, Shey-Ying; Yang, Jyh-Yuan; Lin, Jih-Hui; Yang, Pan-Chyr; Chang, Shan-Chwen

We examined severe acute respiratory syndrome-associated coronavirus (SARS-CoV) RNA in plasma of 32 patients (probable SARS cases) by a quantitative real-time reverse transcription-PCR assay and reported that the highest detection rate, 75%, was found between day 5 and day 7 of illness, followed by rates of 64, 50, and 38% found between day 8 and day 11, day 2 and day 4, and day 12 and day 16, respectively. Analysis of sequential SARS-CoV load in plasma from six cases revealed different patterns of viremia, with the peak between day 4 and day 8. Our findings of the high detection rate of SARS-CoV RNA in plasma before day 11, together with the relative convenience of collecting and handling plasma, suggest that plasma can be used for early diagnosis of SARS.