The Importance of Cycle Threshold Values in the Evaluation of Patients with Persistent Positive PCR for SARS-CoV-2: Case Study and Brief Review

Authors

Jose Bordon, Division of Infectious Diseases, Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA and Washington Health Institute, Washington, D.C., USAFollow
Donghoon Chung, Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY, USAFollow
Priya Krishnan, Division of General Internal Medicine, Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USAFollow
Ruth Carrico, Division of Infectious Diseases, Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USAFollow
Julio A. Ramirez, Division of Infectious Diseases, Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USAFollow

Funder

The author(s) received no specific funding for this work.

Abstract

Some patients recover from COVID-19, but their reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 remains persistently positive. In the evaluation of these patients, it is important to define the cycle threshold (Ct) value of the RT-PCR test. This article will present a case study, address relevant findings and interpretation of the RT-PCR test, and explain the use of Ct values in defining when a healthcare worker may return to work. Our current approach is to allow health care workers with persistently positive RT-PCR to return to work if the Ct value is greater than 35.

DOI

10.18297/jri/vol4/iss1/54

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

Bordon, Jose; Chung, Donghoon; Krishnan, Priya; Carrico, Ruth; and Ramirez, Julio A. (2020) "The Importance of Cycle Threshold Values in the Evaluation of Patients with Persistent Positive PCR for SARS-CoV-2: Case Study and Brief Review," The University of Louisville Journal of Respiratory Infections: Vol. 4 : Iss. 1 , Article 54.
DOI: https://doi.org/10.18297/jri/vol4/iss1/54
Available at: https://ir.library.louisville.edu/jri/vol4/iss1/54