Scholarlink

<p>Real-time reverse transcription polymerase chain reaction (rRT-PCR) is nowadays commonly used to diagnose viral infections. This assay provides cycle threshold (Ct) values, which inversely correlate with viral load but do not directly indicate infectivity. The relationship between Ct values and infectivity remains unclear. As a first step, we assessed this relationship in nasopharyngeal samples from 97 seasonal influenza A (IAV) and 95 influenza B (IBV) virus-rRT-PCR-positive patients. Samples were cultured, viral RNA was quantified using reverse transcriptase digital PCR, and antibody titers against hemagglutinin (HA) were evaluated. We found a robust inverse correlation between sample Ct value and infectious virus titer and virus cultures are consistently positive at Ct &lt; 22 with a 10% positive culture probability near Ct 36, which corresponds to 5.37 × 10<sup>2</sup> and 1.57 × 10<sup>3</sup> RNA copies mL<sup>−1</sup> for seasonal IAV and IBV, respectively. Nearly all available serum samples showed HA-specific antibodies, with no correlation between HA titer and Ct value or virus titer. In conclusion, these results support the use of Ct values as a semiquantitative proxy for infectious viral load and underscore their value in interpreting molecular diagnostics and informing infection prevention and control strategies.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Quantitative relationship between cycle threshold values and infectious influenza virus in patient nasopharyngeal samples

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年6月16日

查看全文
  • Kain S. Saygan,
  • Jeroen J. A. van Kampen,
  • Daphne G. J. C. Mulders,
  • Theo Bestebroer,
  • Dennis de Meulder,
  • Richard Molenkamp,
  • Mirle van Geest,
  • Ron A. M. Fouchier,
  • Sander Herfst,
  • Pieter L. A. Fraaij

摘要

Real-time reverse transcription polymerase chain reaction (rRT-PCR) is nowadays commonly used to diagnose viral infections. This assay provides cycle threshold (Ct) values, which inversely correlate with viral load but do not directly indicate infectivity. The relationship between Ct values and infectivity remains unclear. As a first step, we assessed this relationship in nasopharyngeal samples from 97 seasonal influenza A (IAV) and 95 influenza B (IBV) virus-rRT-PCR-positive patients. Samples were cultured, viral RNA was quantified using reverse transcriptase digital PCR, and antibody titers against hemagglutinin (HA) were evaluated. We found a robust inverse correlation between sample Ct value and infectious virus titer and virus cultures are consistently positive at Ct < 22 with a 10% positive culture probability near Ct 36, which corresponds to 5.37 × 102 and 1.57 × 103 RNA copies mL−1 for seasonal IAV and IBV, respectively. Nearly all available serum samples showed HA-specific antibodies, with no correlation between HA titer and Ct value or virus titer. In conclusion, these results support the use of Ct values as a semiquantitative proxy for infectious viral load and underscore their value in interpreting molecular diagnostics and informing infection prevention and control strategies.