Article Text

Download PDFPDF
Progression/remission of COVID-19: data-driven recommendations for repeating SARS-CoV-2 nucleic acid amplification tests
  1. Nathan Williams1,
  2. Reed Idriss2,
  3. Jessica Dodge1,
  4. Samuel Barasch1
  1. 1 Pathology and Laboratory Medicine, Danbury Hospital, Danbury, Connecticut, USA
  2. 2 Department of Emergency Medicine, Danbury Hospital, Danbury, Connecticut, USA
  1. Correspondence to Dr Samuel Barasch, Pathology and Laboratory Medicine, Danbury Hospital, Danbury, Connecticut, USA; samuel.barasch{at}


Aims This short study was performed to better understand the time frame associated with changes in SARS-CoV-2 nucleic acid testing and provide recommendations for repeat testing. Recommendations are useful as little guidance is available for repeat testing in patients being followed expectantly for changes in disease.

Methods A review of laboratory data of tests for SARS-CoV-2 nucleic acid was performed selecting patients who had changing results. Time between changes in test results was determined to provide guidance for repeat testing.

Results The Interquartile Range (IQR) of data for patients who had a negative to positive change in laboratory testing (progression) was 6–16 days (median=9 days). The IQR of data for patients who had a positive to negative change in test results (remission) was 9–21 days (median=14 days).

Conclusion Because sampling of the nares or nasopharynx can be variable, repeat testing should be performed swiftly when symptomatic patients are negative. The data in this short study vary widely, so authors recommend repeat testing during a period of time associated with the IQR or median (see results above).

  • virology
  • clinical audit
  • quality assurance
  • healthcare

This article is made freely available for use in accordance with BMJ’s website terms and conditions for the duration of the covid-19 pandemic or until otherwise determined by BMJ. You may use, download and print the article for any lawful, non-commercial purpose (including text and data mining) provided that all copyright notices and trade marks are retained.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Handling editor Tahir S Pillay.

  • Contributors All authors contributed to data collection, analysis, interpretation or writing of this submission.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.