tetano
Editor, Senior Moderator
J Clin Virol Plus
. 2021 Jun;1(1):100021.
doi: 10.1016/j.jcvp.2021.100021. Epub 2021 May 16.
Interpretation of single target positivity among SARS-CoV-2 RT-PCR result tests
Honorine Fenaux[SUP] 1 [/SUP], Théo Ghelfenstein-Ferreira[SUP] 1 [/SUP], Maud Salmona[SUP] 1 2 [/SUP], Nadia Mahjoub[SUP] 1 [/SUP], Linda Feghoul[SUP] 1 2 [/SUP], Sarah Maylin[SUP] 1 [/SUP], Marie-Laure Chaix[SUP] 1 3 [/SUP], Marine Minier[SUP] 1 [/SUP], Audrey Gabassi[SUP] 1 3 [/SUP], Jérôme Le Goff[SUP] 1 2 [/SUP], Constance Delaugerre[SUP] 1 3 [/SUP]
Affiliations
Abstract
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently emerged and is responsible for coronavirus disease 19 (COVID-19). Diagnostic tests have been developed, mainly based on reverse-transcriptase PCR (RT-PCR). Most RT-PCR assays target at least two SARS-CoV-2 genes. In some cases, only one target gene is detected; the interpretation of such cases remains unclear.
Objectives: Our objective was to analyse one target positive (OPT) RT-PCR results, using two RT-PCR assays: the Xpert® Xpress SARS-CoV-2 (Cepheid diagnosis, "Cepheid") and the Cobas® 6800 SARS-CoV-2 Test (Roche Molecular Diagnostics, "Roche").
Methods: All SARS-CoV-2 RT-PCR results performed on respiratory samples with the Roche or the Cepheid tests, from 23rd March to 6th August 2020 were collected. A patient with an OPT result was classified as "probable COVID-19" if they met at least one of the three following criteria: (i) history of a two gene-positive SARS-CoV-2 RT-PCR result, (ii) anti-SARS-CoV-2 antibody (IgG) detection or (iii) compatible chest computed tomography scan (CT-scan).
Results: A total of 18,630 and 1189 SARS-CoV-2 RT-PCR tests were performed with the Roche and Cepheid tests, respectively. Among the positive SARS-CoV-2 RT-PCR, 293 samples - corresponding to 264 patients - were OPT (11% of the positive samples). Of these patients, 180 (68%) had at least one of the three criteria listed above and were classified as probable COVID-19.
Conclusions: Sixty-eight percent of the patients with an OPT result were classified as probable COVID-19 and are probably at a late stage of infection. Serology and imaging can be helpful to confirm diagnosis.
Keywords: COVID-19; Molecular biology; One target positive RT-PCR result; SARS-CoV-2.
. 2021 Jun;1(1):100021.
doi: 10.1016/j.jcvp.2021.100021. Epub 2021 May 16.
Interpretation of single target positivity among SARS-CoV-2 RT-PCR result tests
Honorine Fenaux[SUP] 1 [/SUP], Théo Ghelfenstein-Ferreira[SUP] 1 [/SUP], Maud Salmona[SUP] 1 2 [/SUP], Nadia Mahjoub[SUP] 1 [/SUP], Linda Feghoul[SUP] 1 2 [/SUP], Sarah Maylin[SUP] 1 [/SUP], Marie-Laure Chaix[SUP] 1 3 [/SUP], Marine Minier[SUP] 1 [/SUP], Audrey Gabassi[SUP] 1 3 [/SUP], Jérôme Le Goff[SUP] 1 2 [/SUP], Constance Delaugerre[SUP] 1 3 [/SUP]
Affiliations
- PMID: 35262008
- PMCID: PMC8126374
- DOI: 10.1016/j.jcvp.2021.100021
Abstract
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently emerged and is responsible for coronavirus disease 19 (COVID-19). Diagnostic tests have been developed, mainly based on reverse-transcriptase PCR (RT-PCR). Most RT-PCR assays target at least two SARS-CoV-2 genes. In some cases, only one target gene is detected; the interpretation of such cases remains unclear.
Objectives: Our objective was to analyse one target positive (OPT) RT-PCR results, using two RT-PCR assays: the Xpert® Xpress SARS-CoV-2 (Cepheid diagnosis, "Cepheid") and the Cobas® 6800 SARS-CoV-2 Test (Roche Molecular Diagnostics, "Roche").
Methods: All SARS-CoV-2 RT-PCR results performed on respiratory samples with the Roche or the Cepheid tests, from 23rd March to 6th August 2020 were collected. A patient with an OPT result was classified as "probable COVID-19" if they met at least one of the three following criteria: (i) history of a two gene-positive SARS-CoV-2 RT-PCR result, (ii) anti-SARS-CoV-2 antibody (IgG) detection or (iii) compatible chest computed tomography scan (CT-scan).
Results: A total of 18,630 and 1189 SARS-CoV-2 RT-PCR tests were performed with the Roche and Cepheid tests, respectively. Among the positive SARS-CoV-2 RT-PCR, 293 samples - corresponding to 264 patients - were OPT (11% of the positive samples). Of these patients, 180 (68%) had at least one of the three criteria listed above and were classified as probable COVID-19.
Conclusions: Sixty-eight percent of the patients with an OPT result were classified as probable COVID-19 and are probably at a late stage of infection. Serology and imaging can be helpful to confirm diagnosis.
Keywords: COVID-19; Molecular biology; One target positive RT-PCR result; SARS-CoV-2.