tetano
Editor, Senior Moderator
J Clin Microbiol. 2020 Mar 4. pii: JCM.00310-20. doi: 10.1128/JCM.00310-20. [Epub ahead of print] [h=1]Improved molecular diagnosis of COVID-19 by the novel, highly sensitive and specific COVID-19-RdRp/Hel real-time reverse transcription-polymerase chain reaction assay validated in vitro and with clinical specimens.[/h]
Chan JF[SUP]1,[/SUP][SUP]2,[/SUP][SUP]3,[/SUP][SUP]4,[/SUP][SUP]5[/SUP], Yip CC[SUP]6[/SUP], To KK[SUP]1,[/SUP][SUP]2,[/SUP][SUP]3,[/SUP][SUP]4[/SUP], Tang TH[SUP]7[/SUP], Wong SC[SUP]8[/SUP], Leung KH[SUP]3[/SUP], Fung AY[SUP]3[/SUP], Ng AC[SUP]3[/SUP], Zou Z[SUP]3[/SUP], Tsoi HW[SUP]3[/SUP], Choi GK[SUP]6[/SUP], Tam AR[SUP]9[/SUP], Cheng VC[SUP]6[/SUP], Chan KH[SUP]1,[/SUP][SUP]3,[/SUP][SUP]4[/SUP], Tsang OT[SUP]10[/SUP], Yuen KY[SUP]11,[/SUP][SUP]3,[/SUP][SUP]4,[/SUP][SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] On 31[SUP]st[/SUP] December 2019, the World Health Organization was informed of a cluster of cases of pneumonia of unknown etiology in Wuhan, China. Subsequent investigations identified a novel coronavirus, now named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), from the affected patients. Highly sensitive and specific laboratory diagnostics are important for controlling the rapidly evolving SARS-CoV-2-associated Coronavirus Disease 2019 (COVID-19) epidemic. In this study, we developed and compared the performance of three novel real-time RT-PCR assays targeting the RNA-dependent RNA polymerase (RdRp)/helicase (Hel), spike (S), and nucleocapsid (N) genes of SARS-CoV-2 with that of the reported RdRp-P2 assay which is used in >30 European laboratories. Among the three novel assays, the COVID-19-RdRp/Hel assay had the lowest limit of detection in vitro (1.8 TCID[SUB]50[/SUB]/ml with genomic RNA and 11.2 RNA copies/reaction with in vitro RNA transcripts). Among 273 specimens from 15 patients with laboratory-confirmed COVID-19 in Hong Kong, 77 (28.2%) were positive by both the COVID-19-RdRp/Hel and RdRp-P2 assays. The COVID-19-RdRp/Hel assay was positive for an additional 42 RdRd-P2-negative specimens [119/273 (43.6%) vs 77/273 (28.2%), P<0.001], including 29/120 (24.2%) respiratory tract specimens and 13/153 (8.5%) non-respiratory tract specimens. The mean viral load of these specimens was 3.21?10[SUP]4[/SUP] RNA copies/ml (range, 2.21?10[SUP]2[/SUP] to 4.71?10[SUP]5[/SUP] RNA copies/ml). The COVID-19-RdRp/Hel assay did not cross-react with other human-pathogenic coronaviruses and respiratory pathogens in cell culture and clinical specimens, whereas the RdRp-P2 assay cross-reacted with SARS-CoV in cell culture. The highly sensitive and specific COVID-19-RdRp/Hel assay may help to improve the laboratory diagnosis of COVID-19.
Copyright ? 2020 American Society for Microbiology.
PMID: 32132196 DOI: 10.1128/JCM.00310-20
Chan JF[SUP]1,[/SUP][SUP]2,[/SUP][SUP]3,[/SUP][SUP]4,[/SUP][SUP]5[/SUP], Yip CC[SUP]6[/SUP], To KK[SUP]1,[/SUP][SUP]2,[/SUP][SUP]3,[/SUP][SUP]4[/SUP], Tang TH[SUP]7[/SUP], Wong SC[SUP]8[/SUP], Leung KH[SUP]3[/SUP], Fung AY[SUP]3[/SUP], Ng AC[SUP]3[/SUP], Zou Z[SUP]3[/SUP], Tsoi HW[SUP]3[/SUP], Choi GK[SUP]6[/SUP], Tam AR[SUP]9[/SUP], Cheng VC[SUP]6[/SUP], Chan KH[SUP]1,[/SUP][SUP]3,[/SUP][SUP]4[/SUP], Tsang OT[SUP]10[/SUP], Yuen KY[SUP]11,[/SUP][SUP]3,[/SUP][SUP]4,[/SUP][SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] On 31[SUP]st[/SUP] December 2019, the World Health Organization was informed of a cluster of cases of pneumonia of unknown etiology in Wuhan, China. Subsequent investigations identified a novel coronavirus, now named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), from the affected patients. Highly sensitive and specific laboratory diagnostics are important for controlling the rapidly evolving SARS-CoV-2-associated Coronavirus Disease 2019 (COVID-19) epidemic. In this study, we developed and compared the performance of three novel real-time RT-PCR assays targeting the RNA-dependent RNA polymerase (RdRp)/helicase (Hel), spike (S), and nucleocapsid (N) genes of SARS-CoV-2 with that of the reported RdRp-P2 assay which is used in >30 European laboratories. Among the three novel assays, the COVID-19-RdRp/Hel assay had the lowest limit of detection in vitro (1.8 TCID[SUB]50[/SUB]/ml with genomic RNA and 11.2 RNA copies/reaction with in vitro RNA transcripts). Among 273 specimens from 15 patients with laboratory-confirmed COVID-19 in Hong Kong, 77 (28.2%) were positive by both the COVID-19-RdRp/Hel and RdRp-P2 assays. The COVID-19-RdRp/Hel assay was positive for an additional 42 RdRd-P2-negative specimens [119/273 (43.6%) vs 77/273 (28.2%), P<0.001], including 29/120 (24.2%) respiratory tract specimens and 13/153 (8.5%) non-respiratory tract specimens. The mean viral load of these specimens was 3.21?10[SUP]4[/SUP] RNA copies/ml (range, 2.21?10[SUP]2[/SUP] to 4.71?10[SUP]5[/SUP] RNA copies/ml). The COVID-19-RdRp/Hel assay did not cross-react with other human-pathogenic coronaviruses and respiratory pathogens in cell culture and clinical specimens, whereas the RdRp-P2 assay cross-reacted with SARS-CoV in cell culture. The highly sensitive and specific COVID-19-RdRp/Hel assay may help to improve the laboratory diagnosis of COVID-19.
Copyright ? 2020 American Society for Microbiology.
PMID: 32132196 DOI: 10.1128/JCM.00310-20