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Updated: Oct 26, 2025

Author Spotlight: Advancements in Multiplex Detection of Respiratory Viruses
Published on: November 10, 2023
Recurrent and persistent infection with SARS-CoV-2 - epidemiological data and case reports from Western Sweden, 2020
Johan Ringlander1, Josefin Olausson1, Kristina Nyström1
1Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Background:
Reinfections with SARS-CoV-2 have been reported and most cases were classified as mild. Reports of persistent infection with SARS-CoV-2 are rare.
Aim:
To investigate the frequency of recurrent and persistent infection with SARS-CoV-2.
Methods:
Possible cases of reinfection and persistent infection were retrospectively identified in a database of 59,998 patients. Deep sequencing of SARS-CoV-2 genomes was performed.
Results:
We report the first case of COVID-19 reinfection in Sweden and three cases of infection with persistence over several months. The rate of sequencing-verified reinfection was 0.02% (one patient out of 6014 patients testing positive during the period).
Conclusions:
The reinfected patient had mild symptoms during the second episode, which might reflect partial immunity. The frequency of reinfection during the first wave of the pandemic in western Sweden was very low. Our results indicate that elderly with a putative reinfection more likely have persistent COVID-19.

