Marlies Heudobler, Hansjörg Baurecht, Helen Schmied, Daniel Heudobler, Carmen Jochem, Anja M Sedlmeier, Andrea Weber, Stilla Bauernfeind, Michael Leitzmann, Bernd Salzberger, Benedikt M J Lampl
{"title":"Association of epidemiological and clinical features with PCR cycle threshold values of SARS-CoV-2 infection: a cross-sectional study.","authors":"Marlies Heudobler, Hansjörg Baurecht, Helen Schmied, Daniel Heudobler, Carmen Jochem, Anja M Sedlmeier, Andrea Weber, Stilla Bauernfeind, Michael Leitzmann, Bernd Salzberger, Benedikt M J Lampl","doi":"10.1080/20477724.2022.2158003","DOIUrl":null,"url":null,"abstract":"<p><p>The cycle threshold (Ct) in quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) is inversely correlated to the amount of viral nucleic acid or viral load and can be regarded as an indicator of infectivity. We examined the association of socio-demographic and clinical characteristics of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) polymerase chain reaction (PCR) positive cases with PCR cycle threshold (Ct) values at the time of diagnosis. SARS-CoV-2 cases reported between 12 October 2020 and 24 January 2021 in Regensburg were analyzed employing bivariate and multivariable methods. We included 3,029 SARS-CoV-2 cases (31% asymptomatic at diagnosis) and analyzed the association of case characteristics with Ct values in 2,606 cases. Among symptomatic patients, cough (38.0%), rhinitis (32.4%), headache (32.0), and fever/chills (29.9%) were the most frequent complaints. Ct values ≤20 were more frequent in symptomatic cases (20.9% vs. 11.3%), whereas Ct values >30 were more common in asymptomatic cases (32.6% vs. 18.0%). Ct values >20 and ≤30 were most common in symptomatic and asymptomatic cases (48.0% vs 40.7%). We observed lower median Ct values of E and N gene in symptomatic cases. In a random forest model, the total number of symptoms, respiratory symptoms, and age were most strongly associated with low Ct values. In conclusion, certain symptoms and age were associated with lower Ct values. Ct values can be used as a pragmatic approach in estimating infectivity at the first notification of a case and, thus, in guiding containment measures.</p>","PeriodicalId":19850,"journal":{"name":"Pathogens and Global Health","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10262808/pdf/","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Pathogens and Global Health","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1080/20477724.2022.2158003","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2022/12/15 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"PARASITOLOGY","Score":null,"Total":0}
引用次数: 1
Abstract
The cycle threshold (Ct) in quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) is inversely correlated to the amount of viral nucleic acid or viral load and can be regarded as an indicator of infectivity. We examined the association of socio-demographic and clinical characteristics of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) polymerase chain reaction (PCR) positive cases with PCR cycle threshold (Ct) values at the time of diagnosis. SARS-CoV-2 cases reported between 12 October 2020 and 24 January 2021 in Regensburg were analyzed employing bivariate and multivariable methods. We included 3,029 SARS-CoV-2 cases (31% asymptomatic at diagnosis) and analyzed the association of case characteristics with Ct values in 2,606 cases. Among symptomatic patients, cough (38.0%), rhinitis (32.4%), headache (32.0), and fever/chills (29.9%) were the most frequent complaints. Ct values ≤20 were more frequent in symptomatic cases (20.9% vs. 11.3%), whereas Ct values >30 were more common in asymptomatic cases (32.6% vs. 18.0%). Ct values >20 and ≤30 were most common in symptomatic and asymptomatic cases (48.0% vs 40.7%). We observed lower median Ct values of E and N gene in symptomatic cases. In a random forest model, the total number of symptoms, respiratory symptoms, and age were most strongly associated with low Ct values. In conclusion, certain symptoms and age were associated with lower Ct values. Ct values can be used as a pragmatic approach in estimating infectivity at the first notification of a case and, thus, in guiding containment measures.
期刊介绍:
Pathogens and Global Health is a journal of infectious disease and public health that focuses on the translation of molecular, immunological, genomics and epidemiological knowledge into control measures for global health threat. The journal publishes original innovative research papers, reviews articles and interviews policy makers and opinion leaders on health subjects of international relevance. It provides a forum for scientific, ethical and political discussion of new innovative solutions for controlling and eradicating infectious diseases, with particular emphasis on those diseases affecting the poorest regions of the world.