Observational studyThe Journal of infection2021
Recurrent COVID-19 including evidence of reinfection and enhanced severity in thirty Brazilian healthcare workers.
Observational study in The Journal of infection, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 83 papers, 12 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
83 citing papers in PubMed, 12 syntheses or guidelines pooled it, 148 citations in OpenAlex.
- Risk Factors Contributing to Reinfection by SARS-CoV-2: A Systematic Review.Advances in respiratory medicine · 2023Pooled it
- SARS-CoV-2 Genomic Surveillance in Brazil: A Systematic Review with Scientometric Analysis.Viruses · 2022Pooled it
- Risk of SARS-CoV-2 reinfection: a systematic review and meta-analysis.Scientific reports · 2022Pooled it
- Does potential antibody-dependent enhancement occur during SARS-CoV-2 infection after natural infection or vaccination? A meta-analysis.BMC infectious diseases · 2022Pooled it
- The prevalence of adaptive immunity to COVID-19 and reinfection after recovery - a comprehensive systematic review and meta-analysis.Pathogens and global health · 2022Pooled it
- Clinical manifestations, treatment options, and comorbidities in COVID-19 relapse patients: A systematic review.Journal of clinical laboratory analysis · 2022Pooled it
- Reinfection in patients with COVID-19: a systematic review.Global health research and policy · 2022Pooled it
- Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Sequence Characteristics of Coronavirus Disease 2019 (COVID-19) Persistence and Reinfection.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2022Pooled it
- SARS-CoV-2 Reinfection Is a New Challenge for the Effectiveness of Global Vaccination Campaign: A Systematic Review of Cases Reported in Literature.International journal of environmental research and public health · 2021Pooled it
- Severe Acute Respiratory Syndrome Coronavirus 2 Reinfection Cases Corroborated by Sequencing.The American journal of tropical medicine and hygiene · 2021Pooled it
- Reinfection or Reactivation of Severe Acute Respiratory Syndrome Coronavirus 2: A Systematic Review.Frontiers in public health · 2021Pooled it
- Clinical features and corresponding immune function status of recurrent viral polymerase chain reaction positivity in patients with COVID-19 : A meta- analysis and systematic review.International journal of immunopathology and pharmacologyPooled it
- Effectiveness of Molnupiravir and Nirmatrelvir-Ritonavir in Hospitalized Patients With COVID-19 : A Target Trial Emulation Study.Annals of internal medicine · 2023Trial
- COVID-19 Is Airborne AIDS: Provocative Oversimplification, Emerging Science, or Something in Between?AJPM focus · 2026Review
- Association of ABO/Rh Blood Groups and ABO Gene VariantsViruses · 2026Article
- Subsequent SARS-CoV-2 Infection in Healthcare Workers: A Retrospective Cohort Study in Iran.Immunity, inflammation and disease · 2026Article
- Paying Upfront: Successful Initial Infections Protect Against Severe Future Infections.Integrative organismal biology (Oxford, England) · 2026Article
- Compassionate Release and COVID-19: Analyzing Inconsistent Applications of the First Step Act by Federal Courts.The Journal of law, medicine & ethics : a journal of the American Society of Law, Medicine & Ethics · 2025Article
- Reinfection and post-vaccination infection by SARS-CoV-2 in nursing professionals: a prospective cohort study, Recife, 2020-2023.Epidemiologia e servicos de saude : revista do Sistema Unico de Saude do Brasil · 2025Article
- Prescription rates in different groups of outpatients with covid-19 and other acute respiratory infections: comparative observational study based on German routine data.BMJ medicine · 2025Article
23 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
27 authors at 6 institutions in 2 countries.
Funding
Abstract
backgroundThere is growing concern about individuals reported to suffer repeat COVID-19 disease episodes, these in a small number of cases characterised as de novo infections with distinct sequences, indicative of insufficient protective immunity even in the short term.
methodsObservational case series and case-control studies reporting 33 cases of recurrent, symptomatic, qRT-PCR positive COVID-19. Recurrent disease was defined as symptomatic recurrence after symptom-free clinical recovery, with release from isolation >14 days from the beginning of symptoms confirmed by qRT-PCR. The case control study-design compared this group of patients with a control group of 62 patients randomly selected from the same COVID-19 database.
resultsOf 33 recurrent COVID-19 patients, 26 were female and 30 were HCW. Mean time to recurrence was 50.5 days which was associated with being a HCW (OR 36.4 (p <0.0001)), and blood type A (OR 4.8 (p = 0.002)). SARS-CoV-2 antibodies were signifcantly lower in recurrent patients after initial COVID-19 (2.4 ± 0.610; p<0.0001) and after recurrence (6.4 ± 11.34; p = 0.007). Virus genome sequencing identified reinfection by a different isolate in one patient.
conclusionsThis is the first detailed case series showing COVID-19 recurrence with qRT-PCR positivity. For one individual detection of phylogenetically distinct genomic sequences in the first and second episodes confirmed bona fide renfection, but in most cases the data do not formally distinguish between reinfection and re-emergence of a chronic infection reservoir. These episodes were significantly associated with reduced Ab response during initial disease and argue the need for ongoing vigilance without an assumption of protection after a first episode.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.