True prevalence of long-COVID in a nationwide, population cohort study

Seasonal variation in the associations between self-reported long-COVID symptoms and IL-6 signalling-related factors (particularly the rs2228145 variant of the IL-6R gene): A clinical study

This observational study focused on the impact of Interleukin-6 (IL-6)-related factors (notably the IL-6 receptor (IL-6R) gene's rs2228145 polymorphism) on long-COVID risk in individuals who had previously experienced COVID-19 infection(s). The purpose of the study was to better understand such factors' contribution to long-COVID risk, and thus possibly initiate future strategies for using IL-6-related factors as biomarkers predictive of risk (while also obtaining data that may influence long-COVID management and treatment more generally). DNA and blood samples, plus questionnaire responses regarding long-COVID symptoms (including chronic fatigue and cognitive impairment), were collected from 175 participants who had previously experienced COVID-19 infection(s). Potential associations between self-reported long-COVID symptoms and participants' rs2228145 genotypes (determined using TaqMan-based genotyping assays) and/or their circulating IL-6, sIL-6R and sgp130 levels (determined using ELISA) were evaluated. Univariate-regression analyses demonstrated that odds of exhibiting long-COVID symptoms increased with severity/number of previous COVID-19 infection(s) and with hypertension as a co-morbidity, while vaccination decreased the likelihood of developing long-COVID. While long-COVID sufferers exhibited higher IL-6 signalling activity than healthy control individuals, rs2228145 genotype was not associated with long-COVID odds-ratios in- the entire-study cohort. Following identification of significant seasonal variations within our dataset, the entire-study cohort was stratified depending on when samples/questionnaire responses were obtained. In the resulting 'summer' sub-cohort (but not the 'winter' sub-cohort), the rs2228145 AA genotype was significantly over-represented amongst those exhibiting long-COVID symptoms, and long-COVID odds-ratios were significantly reduced for the CC and AC genotypes. While interpretation is complicated by seasonal variations, these findings may be of medical/biomedical value. Importantly, as IL-6 was higher in long-COVID sufferers than healthy controls, and rs2228145 AA genotype-bearing individuals within our 'summer' sub-cohort were at elevated risk of developing long-COVID, these findings point towards possible future use of IL-6 and/or rs2228145 genotype as biomarkers predictive of long-COVID risk, which may bring advantages regarding management and treatment of long-COVID.

Long COVID in patients with systemic lupus erythematosus: A case-control study

BackgroundLong COVID was defined by the WHO as continuation or development of new symptoms 3 months after the initial SARS-CoV2 infection, with these symptoms lasting for ≥2 months without alternative explanations.ObjectivesTo compare the incidence of long COVID in patients with SLE with matched controls after a SARS-CoV2 infection.MethodsConsecutive patients (≥18 years) who fulfilled the ACR or SLICC criteria for SLE between July to November 2023 were recruited. Those with SARS-CoV2 infection (positive rapid antigen test [RAT] or PCR) were identified by a self-reported questionnaire, which also captured the duration and severity of a number of pre-defined symptoms of long COVID. An equal number of healthy subjects, matched for gender and age, who had SARS-CoV2 infection in the same period were recruited for the same survey. The incidence and presentation of long COVID was compared between patients and controls, and risk factors for long COVID in SLE patients were studied.ResultsA total of 211 SLE patients (97.6% women, age 44.2 ± 11.9 years) and 211 healthy controls (97.6% women, age 44.2 ± 11.9 years) were studied. In all patients, the most common long COVID symptoms were fatigue (30.1%), worsening of memory (29.1%), difficulty to concentrate (26.3%), cough (23.2%) and insomnia (18.9%). Compared with controls, the incidence of long COVID was significantly higher in SLE patients (54.5% vs 34.6%; OR 2.27 [1.53-3.35]). Symptoms of worsening of memory (OR 2.77 [1.78-4.31]), chest pain (OR 4.18 [1.16-15.0]), palpitation (OR 3.43 [1.58-7.47]) and arthralgia (OR 2.67 [1.29-5.53]) were significantly more common in SLE patients than controls. However, no clinical and serological factors were significantly associated with the occurrence of long COVID in SLE patients except the ever use of hydroxychloroquine (OR 2.03 [1.04-3.96]).ConclusionsLong COVID is more common in SLE patients than matched controls after a SARS-CoV2 infection. The development of long COVID symptoms in SLE is largely unpredictable.

[Association between obesity and Long-Covid: A narrative review]

To analyze the evidence in the scientific literature that relates Long-Covid and obesity, a narrative review of articles published in English and Spanish in Medline and Embase in the last 5years has been carried out. Infection with the SARS-CoV-2 virus causes a systemic inflammatory state increasing nutritional demand that favors sarcopenia in Long-Covid syndrome. It also causes endothelial dysfunction and a prothrombotic state that favors the formation of microthrombi and tissue hypoxia. A healthy and balanced diet is essential to treat obesity in addition to modifying the microbiota in Long-Covid and promoting physical and mental well-being. Obesity is an independent risk factor that increases the need for hospitalization, cardiovascular risk and mortality, as well as susceptibility to Long-Covid. Adipose tissue is a good reservoir of the virus, enhancing the comorbidities associated with obesity (high blood pressure, diabetes mellitus, dyslipidemia or fatty liver). There is insufficient evidence to recommend nutritional supplements to improve Long-Covid symptoms.

Maximal oxygen uptake, pulmonary function and walking economy are not impaired in patients diagnosed with long COVID

INTRODUCTION

SARS-CoV-2 may result in the development of new symptoms, known as long COVID, a few months after the original infection.

PURPOSE

It is elusive to what extent physical capacity in patients diagnosed with long COVID is impacted.

METHODS

We compared maximal oxygen uptake (V̇O2max), one of the single most important factors for cardiovascular health and mortality, expired lung volumes and air flow, oxygen cost of walking and 6-min-walking-test (6MWT), in 20 patients diagnosed with long COVID (11 males and 9 females; 44 ± 16 years (SD); 26.7 ± 3.8BMI, duration of acute phase 1.7 ± 1.2 weeks, tested 4 ± 3 months after long COVID diagnosis) with 20 healthy age and sex matched controls (11 males and 9 females; 44 ± 16 years; 25.9 ± 4.0BMI).

RESULTS

Long COVID patients had a V̇O2max of 41.4 ± 16.2 mL∙kg-1∙min-1(men) and 38.2 ± 7.5 (women) and this was not different from controls. Similarly, mean spirometry measures in the patient group (VC; FVC; FEV1; FEV1/FVC) were also not different (85-106%) from predicted healthy values. Finally, inclined treadmill (5%, 4 km∙h-1) walking economy was not different between the groups (long COVID: 15.2 ± 1.1 mL∙kg-1∙min-1; controls: 15.2 ± 1.2 mL∙kg-1∙min-1), while the 6MWT revealed a difference (long COVID: 606 ± 118 m; controls: 685 ± 85 m; p = 0.036).

CONCLUSION

V̇O2max, oxygen cost of walking, and spirometry measurements did not appear to be impaired in patients diagnosed with long COVID with a prior mild to moderate SARS-CoV-2 infection. The typical outcomes in these essential factors for health and longevity implies that while long COVID can present with a range of symptoms, caution should be made when attributing these symptoms directly to compromised pulmonary function or V̇O2max.

Two-year impact of COVID-19: Longitudinal MRI brain changes and neuropsychiatric trajectories

AIM

Up to 10% of SARS-CoV-2 infected individuals suffer from post-COVID-19 condition, marked by fatigue and cognitive dysfunction as major symptoms. Longitudinal studies on neuropsychological and clinical trajectories and related brain changes are scarce. Here, we aimed to examine their evolution up to 2 years post-infection.

METHODS

In a multi-center, longitudinal study of 79 post-COVID patients (mean age 46, 48 female) with persistent symptoms and 21 age- and sex-matched never-infected, healthy controls (mean age 42, eight female), we analyzed neuropsychological performance, self-reported outcomes and associated neuroimaging alterations of resting-state functional and structural magnetic resonance imaging data 23 months post-infection.

RESULTS

In post-COVID patients 23 months after SARS-CoV-2 infection we observed (1) that fatigue severity had reduced but still remained present in most patients, (2) widespread brain changes involving the brainstem, the pre- and postcentral gyrus and the limbic olfactory network, (3) a weakening of self-reported fatigue and its cerebral associations. Notably, findings of brain aberrations were more pronounced in hospitalized patients.

CONCLUSION

Our findings indicate that complex brain adaptations take place up to 2 years following SARS-CoV-2 infection. Some regions manifest enduring abnormalities while others undergo restitution. The attenuation of radio-clinical associations suggests a compensatory function for these regions, pointing to non-brain intrinsic factors to sustain persistent fatigue.

Long COVID: Pathophysiology, current concepts, and future directions

Long COVID, an umbrella term referring to a variety of symptoms and clinical presentations that emerges in a subset of patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has a significant effect on quality of life and places a substantial burden on health care systems worldwide, straining financial and human resources. The pathophysiology of long COVID remains incompletely understood, though several hypotheses have been proposed to explain different aspects of this complex condition. SARS-CoV-2 persistence, direct organ damage, innate and adaptive immune system perturbation, autoimmunity, latent virus reactivation, endothelial dysfunction, and microbiome disturbances are among the most relevant avenues for elucidating the evolution, complexity, and mechanisms of long COVID. Active investigation regarding potential biomarkers for long COVID and its associated disease endotypes highlights the role of inflammatory mediators, immunophenotyping, and multiomics approaches. Further advances in understanding long COVID are needed to inform current and future therapeutics.

Healthcare Resource Utilization (HCRU) and Direct Medical Costs Associated with Long COVID or Post-COVID-19 Conditions: Findings from a Literature Review

Approximately 10-20% of individuals suffering from COVID-19 develop prolonged symptoms known as long COVID or post-COVID condition (LC). This review aimed to assess healthcare resource use (HCRU) and healthcare costs associated with LC. Because LC is not clearly defined and often remains undiagnosed, studies reporting on long-term follow-up of individuals with a COVID-19 diagnosis were also included. Among the 41 publications included, 36 reported on HCRU and 16 on costs. Individuals with LC had significantly elevated HCRU and healthcare costs vs. controls without a COVID-19 diagnosis over ≥15 months, with a 7.6-13.1% increase in total healthcare costs per person per month as assessed by difference-in-difference analysis. Among studies that did not specifically refer to LC, having a COVID-19 diagnosis was associated with a significant 4-10% increase in long-term total HCRU over 6-8 months and a 1.3- to 2.9-fold relative increase in total healthcare costs over 6 months. Due to the heterogeneity of the included studies, high-quality evidence is needed to better understand the economic burden of LC. In the absence of effective treatments, prioritizing the prevention of acute COVID-19, e.g., through vaccination, may be crucial for preventing LC and the associated long-term HCRU and medical spending.

Long COVID Illness: Disparities in Understanding and Receipt of Care in Emergency Department Populations

STUDY OBJECTIVE

Most long coronavirus disease (long COVID) studies rely on traditional surveillance methods that miss underserved populations who use emergency departments (EDs) as their primary health care source. In medically underserved ED populations, we sought to determine (1) whether there are gaps in awareness and self-declared understanding about long COVID illness, and (2) the prevalence, impact on school/work attendance, and receipt of care for long COVID symptoms.

METHODS

This study was a cross-sectional, convenience sample survey study of adult patients at 11 geographically representative US EDs from December 2022 to October 2023. Awareness and self-declared understanding about long COVID illness were measured. Prevalence, impact on school/work attendance, and receipt of care for long COVID symptoms were also assessed.

RESULTS

Of 1,618 eligible patients, 1455 (89.9%) agreed to participate, including 33.4% African Americans and 30.9% Latino/a. Of the patients, 17.1% lacked primary care. In total, 33.2% had persistent COVID-19 symptoms lasting >1 month, and 20.3% had symptoms >3 months. Moreover, 49.8% with long COVID symptoms missed work/school because of symptoms; 30.3% of all participants and 33.5% of participants who had long COVID symptoms had prior awareness and self-declared understanding of long COVID. Characteristics associated with poor understanding of long COVID were African American race (adjusted odds ratio [aOR] 3.68, 95% confidence interval [CI] 2.66 to 5.09) and Latino/a ethnicity (aOR 3.16, 95% CI 2.15 to 4.64). Participants lacking primary care were less likely to have received long COVID care (24.6% versus 51.2%; difference 26.6%; 95% CI 13.7% to 36.9%).

CONCLUSIONS

Despite high prevalence and impact on school/work attendance of long COVID symptoms, most of this ED population had limited awareness and self-declared understanding of long COVID, and many had not received care. EDs should consider the development of protocols for diagnosis, education, and treatment of long COVID illness.

Assessment of psychosocial aspects in adults in post-COVID-19 condition: the EURONET-SOMA recommendations on core outcome domains for clinical and research use

BACKGROUND

Harmonizing core outcome domains allows for pooling data, comparing interventions, and streamlining research evaluation. At the same time clinicians require concise and feasible measures for routine practice. Considering the heterogeneity of post-COVID-19 condition, a biopsychosocial approach requires sufficient coverage of the psychosocial dimension with assessments. Previous recommendations for core outcome sets have serious limitations regarding the psychosocial aspects of post-COVID-19 condition. This paper specifically focuses on psychosocial outcomes for adults with post-COVID-19 condition, providing both a comprehensive set of outcome domains for research and a streamlined clinical core set tailored for routine clinical use.

METHODS

In a structured Consensus Development Approach, the European Network to improve diagnostic, treatment, and healthcare for patients with persistent somatic symptoms (EURONET-SOMA) developed psychosocial core outcome domains and assessments regarding post-COVID-19 condition. The experts identified variables and instruments which should be considered in studies on adults suffering from post-COVID-19 condition, and which are feasible in the clinical setting and relevant for research.

RESULTS

We identified three higher-order dimensions with each encompassing several domains: The first higher-order dimension, "outcomes", encompasses (1) the classification/ diagnostics of post-COVID-19 condition, (2) somatic symptoms (including fatigue), (3) the psychopathological status and mental comorbidities, (4) the physical status and somatic comorbidities, (5) neurocognitive symptoms, and (6) illness consequences. The second higher-order domain "mechanisms" encompasses (7) cognitive components, (8) affective components, (9) behavioral components, (10) social components, and (11) psychobiological bridge markers (e.g., neuroimmunological and psychoneuroendocrinological variables). The third higher-order domain, "risk factors", includes factors such as (12) socioeconomic status and sociocultural factors, (13) pre-existing mental and somatic health issues, (14) personality factors (e.g., neuroticism), (15) adverse childhood experiences, (16) ongoing disability or pension claim, and (17) social media use. For each domain, specific instruments are suggested for research purposes and clinical use.

CONCLUSIONS

The recommended core domains help to increase consistency in a biopsychosocial approach to post-COVID-19 condition across investigations, improve synergies, and facilitate decision-making when comparing different interventional approaches. It allows to better identify relevant subgroups in heterogeneous post-COVID-19 condition populations offering practical tools for routine clinical practice through the clinical core set.

Serotonergic psychedelics as potential therapeutics for post-COVID-19 syndrome (or Long COVID): A comprehensive review

RATIONALE

In our ongoing battle against the coronavirus 2019 (COVID-19) pandemic, a major challenge is the enduring symptoms that continue after acute infection. Also known as Long COVID, post-COVID-19 syndrome (PCS) often comes with debilitating symptoms like fatigue, disordered sleep, olfactory dysfunction, and cognitive issues ("brain fog"). Currently, there are no approved treatments for PCS. Recent research has uncovered that the severity of PCS is inversely linked to circulating serotonin levels, highlighting the potential of serotonin-modulating therapeutics for PCS. Therefore, we propose that serotonergic psychedelics, acting mainly via the 5-HT2A serotonin receptor, hold promise for treating PCS.

OBJECTIVES

Our review aims to elucidate potential mechanisms by which serotonergic psychedelics may alleviate the symptoms of PCS.

RESULTS

Potential mechanisms through which serotonergic psychedelics may alleviate PCS symptoms are discussed, with emphasis on their effects on inflammation, neuroplasticity, and gastrointestinal function. Additionally, this review explores the potential of serotonergic psychedelics in mitigating endothelial dysfunction, a pivotal aspect of PCS pathophysiology implicated in organ dysfunction. This review also examines the potential role of serotonergic psychedelics in alleviating specific PCS symptoms, which include olfactory dysfunction, cognitive impairment, sleep disturbances, and mental health challenges.

CONCLUSIONS

Emerging evidence suggests that serotonergic psychedelics may alleviate PCS symptoms. However, further high-quality research is needed to thoroughly assess their safety and efficacy in treating patients with PCS.

Phase-resolved Functional Lung MRI Reveals Distinct Lung Perfusion Phenotype in Children and Adolescents with Post-COVID-19 Condition

Background Although measurable organic dysfunctions are frequently absent in pediatric patients with post-COVID-19 condition (PCC), this condition adversely affects quality of life. Free-breathing phase-resolved functional lung (PREFUL) MRI may be useful for assessing lung function in pediatric patients with PCC. Purpose To detect lung changes in children and adolescents with PCC compared with healthy control participants using PREFUL MRI. Materials and Methods In this single-center, prospective, cross-sectional study conducted between April 2022 and April 2023, children and adolescents (age ≤17 years) with PCC and age- and sex-matched healthy participants underwent MRI. Subgroup analysis was performed in participants with PCC who had cardiopulmonary symptoms. Regional ventilation, flow-volume loop correlation metric (FVL-CM), quantified perfusion, ventilation and perfusion defect percentages, and ventilation-perfusion ratios were compared between participants with PCC and controls using the Wilcoxon signed rank test. Correlation of imaging parameters with spirometry, heart rate, respiratory rate, and Bell score (fatigue severity) in participants with PCC was assessed using the Spearman rank correlation coefficient. Results The final study sample included 54 participants (27 participants with PCC and 27 matched control participants; median age, 15 years [IQR, 11-17 years]; 14 male participants). Twenty-one participants had cardiopulmonary symptoms. Participants with PCC had lower regional ventilation (median, 0.2 mL/mL [IQR, 0.1-0.2 mL/mL] vs 0.2 mL/mL [IQR, 0.2-0.2 mL/mL]; P = .047) and quantified perfusion (49 mL/min per 100 mL [IQR, 33-60 mL/min per 100 mL] vs 78 mL/min per 100 mL [IQR, 59-89 mL/min per 100 mL]; P < .001). Participants with PCC and cardiopulmonary symptoms had lower FVL-CMs (median, 0.99 arbitrary units [au] [IQR, 0.98-0.99 au] vs 0.99 au [IQR, 0.99-0.99 au]; P = .01) and higher ventilation defect (median, 7.6% [IQR, 4.5%-15.1%] vs 5.4% [IQR, 2.7%-7.1%]; P = .047) and perfusion defect percentage (median, 3.2% [IQR, 2.4%-4.2%] vs 2.3% [IQR, 1.8%-3.5%]; P = .02) compared with matched control participants. In participants with PCC, greater lung perfusion correlated with increased chronic fatigue severity (ρ = 0.48; P = .009) and higher ventilation-perfusion mismatch correlated with increased heart rate (ρ = 0.44; P = .02). Conclusion Free-breathing phase-resolved functional lung MRI-derived parameters helped identify a distinct phenotype of lung perfusion in children and adolescents with PCC and were correlated with heart rate and chronic fatigue severity. Clinical trial registration no. DRKS00028963 © RSNA, 2025 Supplemental material is available for this article. See also the editorial by Parraga and Svenningsen in this issue.

Identifying people with post-COVID condition using linked, population-based administrative health data from Manitoba, Canada: prevalence and predictors in a cohort of COVID-positive individuals

OBJECTIVE

Many individuals exposed to SARS-CoV-2 experience long-term symptoms as part of a syndrome called post-COVID condition (PCC). Research on PCC is still emerging but is urgently needed to support diagnosis, clinical treatment guidelines and health system resource allocation. In this study, we developed a method to identify PCC cases using administrative health data and report PCC prevalence and predictive factors in Manitoba, Canada.

DESIGN

Cohort study.

SETTING

Manitoba, Canada.

PARTICIPANTS

All Manitobans who tested positive for SARS-CoV-2 during population-wide PCR testing from March 2020 to December 2021 (n=66 365) and were subsequently deemed to have PCC based on International Classification of Disease-9/10 diagnostic codes and prescription drug codes (n=11 316). Additional PCC cases were identified using predictive modelling to assess patterns of health service use, including physician visits, emergency department visits and hospitalisation for any reason (n=4155).

OUTCOMES

We measured PCC prevalence as % PCC cases among Manitobans with positive tests and identified predictive factors associated with PCC by calculating odds ratios with 95% confidence intervals, adjusted for sociodemographic and clinical characteristics (aOR).

RESULTS

Among 66 365 Manitobans with positive tests, we identified 15 471 (23%) as having PCC. Being female (aOR 1.64, 95% CI 1.58 to 1.71), being age 60-79 (aOR 1.33, 95% CI 1.25 to 1.41) or age 80+ (aOR 1.62, 95% CI 1.46 to 1.80), being hospitalised within 14 days of COVID-19 infection (aOR 1.95, 95% CI 1.80 to 2.10) and having a Charlson Comorbidity Index of 1+ (aOR 1.95, 95% CI 1.78 to 2.14) were predictive of PCC. Receiving 1+ doses of the COVID-19 vaccine (one dose, aOR 0.80, 95% CI 0.74 to 0.86; two doses, aOR 0.29, 95% CI 0.22 to 0.31) decreased the odds of PCC.

CONCLUSIONS

This data-driven approach expands our understanding of the prevalence and epidemiology of PCC and may be applied in other jurisdictions with population-based data. The study provides additional insights into risk and protective factors for PCC to inform health system planning and service delivery.

Remotely delivered weight management for people with long COVID and overweight: the randomized wait-list-controlled ReDIRECT trial

Long COVID (LC) is a complex multisymptom condition with no known disease-modifying treatments. This wait-list-controlled open-label trial tested whether a remotely delivered structured weight management program could improve respective LC symptoms in people living with overweight. Adults with LC (symptoms >12 weeks) and body mass index >27 kg m-2 (>25 kg m-2 for South Asians) were randomized (n = 234, 1:1) to control (n = 116, usual care) or the remotely delivered structured weight management (n = 118, total diet replacement (850 kcal per day) for 12 weeks, followed by food reintroduction and weight loss maintenance support) via minimization and randomization (80:20) to balance dominant LC symptom, sex, age, ethnicity and postcode-based index of multiple deprivation between groups. The control group received the intervention after 6 months. Participants selected the dominant LC symptom they would most like to improve (fatigue, breathlessness, pain, anxiety/depression or other) as the prespecified respective primary outcome. Individual symptoms were assessed using validated questionnaires and a visual analog scale for those without prespecified scales. At 6 months, the primary outcome improved in the intervention group (change -1.16 (s.d. 1.42), n = 97 analyzed) compared with the control group (change -0.83 (s.d. 1.14), n = 117 analyzed) with a treatment effect of -0.34 (95% confidence interval -0.67 to -0.01), with no excess of serious adverse events. International Standard Randomised Controlled Trial Number Registry registration: ISRCTN 12595520 .

Clinical Comparison of Post-intensive Care Syndrome and Long Coronavirus Disease

Post-intensive care syndrome (PICS) encompasses persistent physical, psychological, and cognitive impairments. The coronavirus disease of 2019 (COVID-19) pandemic highlighted parallels between PICS and "long COVID". There is an overlap between the 2 in risk factors, symptoms, and pathophysiology. Physical impairments in both include weakness and fatigue. Cognitive impairments include executive dysfunction in PICS and "brain fog" in long COVID. Mental health issues consist of depression, anxiety, and posttraumatic stress disorder in both disease states. Long COVID and PICS impact families, with multifaceted effects on physical health, mental well-being, and socioeconomic stability. Understanding these syndromes is crucial for comprehensive patient care and family support.

Prevalence of post-acute sequelae of SARS-CoV-2 infection in people living with HIV: a systematic review with meta-analysis

Background

Given the chronic immune activation and inflammatory milieu associated with Long COVID and HIV, we assessed the prevalence of Long COVID in adults living with HIV; and investigated whether adults living with HIV were associated with increased chance of developing Long COVID compared to adults living without HIV.

Methods

In this systematic review and meta-analysis, we searched Medline, EMBASE, CINHAL, PubMed and CENTRAL from inception until June 14th, 2024, for observational studies that measured the prevalence of Long COVID in adults living with HIV and the odds of developing Long COVID following a SARS-CoV-2 infection in people living with HIV compared to people living without HIV. Reviews, case reports, randomised control trials and editorials were excluded. The search was conducted without language restrictions. We performed meta-analysis of proportions to synthesise prevalence estimates using logit transformation and a sensitivity analysis using mixed-effects logistic regression. We used random-effects meta-analyses to summarize the odds ratio (OR) of developing Long COVID in adults living with HIV compared to adults living without HIV and conducted a sensitivity analysis including only studies with covariate-adjusted estimates that was planned a-priori. We used ROBINS-E for the risk of bias assessment and GRADE to rate the certainty of evidence. We identified statistical heterogeneity using Cochran's Q test and quantified it using the I2 statistic. For the Q test, a P < 0.10 was considered statistically significant. PROSPERO registration: CRD42024577616.

Findings

Our search returned 831 results, of which 8 studies (4489 participants) were deemed eligible for inclusion in the systematic review and meta-analysis. The prevalence of Long COVID in adults with HIV was 43% (95% CI: 32-54%, 8 studies; 1227 participants; low certainty, I2 < 0.0001). The association of HIV status with Long COVID was inconclusive, with wide confidence intervals (OR: 1.16, 95% CI: 0.58-2.29; 4 studies; 3556 participants, low certainty, I2 = 0.013). When the analysis was restricted to studies reporting covariate-adjusted estimates, adults living with HIV were associated with a higher odds of Long COVID than those not living with HIV (OR: 2.21, 95% CI: 1.12-4.36; 2 studies; 374 participants, low certainty, I2 = 0.51).

Interpretation

Current evidence indicates that the prevalence of Long COVID in adults living with HIV may be high, suggesting the need for increased awareness and education of healthcare providers and policy makers. Evidence on whether HIV positivity increases the risk of Long COVID is limited and inconclusive, highlighting a need for further research to clarify this potential association.

Funding

None.

Development and validation of the Post-COVID Symptom Scale for Children/Youth (PCSS-C/Y)

This study aims to develop and validate the Post-COVID Symptom Scale for Children/Youth (PCSS-C/Y), which is a comprehensive tool for measuring the symptom burden of post-COVID-19 conditions-persistent symptoms after SARS-CoV-2 infection, commonly known as Long COVID-and its impact on health-related quality of life among children and adolescents. Parents of children and adolescents, adolescents, and young adults with and without a history of COVID-19 were invited to fill in a questionnaire from October 2022 to June 2023. There were 386 valid parent proxy-reported responses, 433 valid adolescent self-reported responses, and 324 valid young adult self-reported responses included in the final analysis. The PCSS-C/Y demonstrated stable factor structure and good internal consistency in different sampling groups. The scale score was negatively associated with Paediatric Quality of Life Inventory (PedsQL) scores (young adult self-report, adjusted R2 = 0.394; adolescent self-report, adjusted R2 = 0.219; parent-report, adjusted R2 = 0.292), while it was positively associated with Strengths and Difficulties Questionnaire (SDQ) scores (young adult self-report, adjusted R2 = 0.195; adolescent self-report, adjusted R2 = 0.154; parent-report, adjusted R2 = 0.239). The scale can also discriminate the post-infected cases and control cases, Cohen's d = 0.41, 0.50, and 0.38 for adult self-report, adolescent self-report, and parent-report, respectively. Conclusions: The PCSS-C/Y is a valid and reliable tool for quantifying the diverse symptomatology of post-COVID-19 conditions in children and adolescents. It provides quantifiable measurements that enable clinicians to monitor post-COVID-19 symptoms in children and young people and facilitates the development of interventions for post-COVID-19 conditions.

Special Issue: "Post-COVID-19 Syndrome"

On 30 January 2020, the World Health Organization declared COVID-19 a Public Health Emergency of International Concern (PHEIC)-the highest WHO warning level [...].

Brief Outpatient Rehabilitation Program for Post-COVID-19 Condition: A Randomized Clinical Trial

Importance

Post-COVID-19 condition (PCC) is emerging as a common and debilitating condition with few treatment options.

Objective

To assess the effectiveness of a brief outpatient rehabilitation program based on a cognitive and behavioral approach for patients with PCC.

Design, Setting, and Participants

Patients with mild to moderate PCC were randomized 1:1 to an established transdiagnostic rehabilitation program or care as usual at a single referral center recruiting from the region of the South-Eastern Norway Regional Health Authority. Participants were followed up after treatment completion and 12 months after enrollment using participant-reported outcome measures. Data were collected from February 22, 2022, until April 15, 2024. Intention-to-treat analysis was performed.

Intervention

The program consisted of 2 to 8 outpatient encounters with approximately 2 to 6 weeks between each encounter. The intervention was theoretically grounded in the cognitive activation theory of stress, and physicians and physiotherapists were trained in cognitive and behavioral approaches with targeted negative stimuli and response outcome expectancies being particularly important.

Main Outcomes and Measures

Participant-reported physical function assessed by the Short-Form Health Survey 36 Physical Function Subscale (SF-36-PFS) served as the primary outcome. Secondary outcome measures were the remaining subscales of the SF-36, return to work self-efficacy and symptom scores on fatigue, postexertional malaise, breathlessness, cognitive difficulties, sleep problems, anxiety and depression symptoms, and smell and taste abnormalities. Safety measures included primary health care contacts; hospital admissions; initiation of pharmacologic and/or nonpharmacologic therapy; occurrence of novel disease, illness, or other health problems; worsening of selected key symptoms; working abilities; and thoughts of suicide.

Results

A total of 473 patients with mild to moderate PCC were assessed for eligibility (n = 364 physician referred; n = 109 self-referred); 314 were included (225 females [72%]; mean [SD] age, 43 [12] years) and 231 completed the primary end point evaluation. The SF-36-PFS scores improved statistically and clinically significantly in the intervention group (score difference between groups, 9.2; 95% CI, 4.3-14.2; P < .001; Cohen d = 0.43; intention-to-treat analysis). The effect was sustained over time. Most secondary and safety measures favored the intervention.

Conclusions and Relevance

In this randomized clinical trial, a brief outpatient rehabilitation program with a cognitive and behavioral approach in patients with PCC was effective and safe. This trial adds to the evidence supporting such interventions in routine clinical care. Future research should investigate which elements of this approach are the most effective and identify subgroups for which the current treatment is most relevant.

Trial Registration

ClinicalTrials.gov Identifier: NCT05196451.

Did aetiology matter in illness duration and complications in patients presenting in primary care with acute respiratory tract infections early in the COVID-19 pandemic: An observational study in nine countries

BACKGROUND

Despite considerable research into COVID-19 sequelae, little is known about differences in illness duration and complications in patients presenting in primary care with symptoms of acute respiratory tract infections (RTI) that are and are not attributed to SARS-CoV-2 infection.

OBJECTIVE

To explore whether aetiology impacted course of illness and prediction of complications in patients presenting in primary care with symptoms of RTI early in the COVID-19 pandemic.

METHODS

Between April 2020-March 2021 general practitioners from nine European countries recruited consecutively contacting patients with RTI symptoms. At baseline, an oropharyngeal-nasal swab was obtained for aetiology determination using PCR after follow-up of 28 days. Time to self-reported recovery was analysed with Kaplan-Meier curves. Predictors (baseline variables of demographics, patient and disease characteristics) of a complicated course (composite of hospital admission and persisting signs/symptoms at 28 days follow-up) were explored with logistic regression modelling.

RESULTS

Of 855 patients with RTI symptoms, 237 (27.7%) tested SARS-CoV-2 positive. The proportion not feeling fully recovered (15.6% vs 18.1%, p = 0.39), reporting being extremely tired (9.7% vs 12.8%, p = 0.21), and not having returned to usual daily activities (18.1% vs 14.4%, p = 0.18) at day 28 were comparable between SARS-CoV-2 positive (n = 237) and negative (n = 618) groups. However, among those feeling fully recovered (SARS-CoV-2 positive: 200 patients, SARS-CoV-2 negative: 506 patients), time to full recovery was significantly longer in SARS-CoV-2 patients (10.6 vs 7.7 days, p < 0.001). We found no evidence that predictors of a complicated course differed between groups (p = 0.07).

CONCLUSION

Early in the pandemic, the proportion of patients not feeling fully recovered by 28 days was similar between SARS-CoV-2 positive and negative patients presenting in primary care with RTI symptoms, but it took somewhat longer for SARS-CoV-2 patients to feel fully recovered. More research is needed on predictors of a complicated course in RTI.

Long-term symptoms after SARS-CoV-2 infection in a cohort of people living with HIV

BACKGROUND

Our Hospital in Northern Italy assists 3817 people living with HIV (PLWH) and has faced the impact of COVID-19. Little is known about the impact of HIV infection on the risk of post-COVID-19 conditions (PCCs) onset. We aim to assess the incidence of PCC in PLWH and the factors associated with its occurrence.

METHODS

We performed a retrospective, observational study including all PLWH > 18 years registered in the Brescia Health Protection Agency database, assessing SARS-CoV-2 burden, vaccination status, socio-demographic, and viro-immunological parameters from February 2020 until May 2022. Persistence of self-reported symptoms (clustered into gastrointestinal, respiratory, osteo-muscular, and neuro-behavioral symptoms) was evaluated after 3 months by a telephone-administered questionnaire. We estimated the associations between all variables and outcomes through univariate and multivariable logistic models.

RESULTS

In the study period, 653 PLWH were diagnosed with SARS-CoV-2 infection (17.1%). We observed 19 (2.9%) reinfections, 71 (10.9%) hospitalizations, and 3 (0.5%) deaths. We interviewed 510/653 PLWH (78%), and 178 (PCCs prevalence 34.9%; CI 95% 30.7-39.2) reported persistent symptoms. Asthenia/fatigue was the most reported symptom (60/178), followed by muscular pain (54/178). In the multivariate regression model, there was a lower risk of PCCs in males respect to females (adjusted OR = 0.64; CI 95% 0.99-3.66), while hospitalization during acute infection was associated with an increased the risk of PCCs (adjusted OR = 1.9; CI 95% 0.99-3.66). Notably, no viro-immunological variable modified the PCCs risk onset.

CONCLUSIONS

Our study highlights a substantial prevalence of PCCs among PLWH, three months post-SARS-CoV-2 infection, independent of viro-immunological features or vaccination status.

COVID-19 vaccination modified the effect of nirmatrelvir-ritonavir on post-acute mortality and rehospitalization: a retrospective cohort study

While previous research examined coronavirus disease 2019 (COVID-19) antiviral-vaccine interactions through exploratory subgroup analysis, none specifically designed for examining this interaction or its impact on post-acute outcomes. This study examined the interaction between nirmatrelvir-ritonavir and complete COVID-19 vaccination on reducing the risk of post-acute outcomes among COVID-19 patients. We followed COVID-19 patients hospitalized between 11 March 2022 and 10 October 2023, until 31 October 2023 in Hong Kong. Exposure groups were based on nirmatrelvir-ritonavir usage and vaccination status (fully or not fully vaccinated). Post-acute death and all-cause rehospitalization were the study outcomes. Propensity score weighting was applied to balance covariates among exposure groups, including age, sex, Charlson Comorbidity Index, and concomitant treatments. Multiplicative and additive interactions between nirmatrelvir-ritonavir and vaccination status were assessed. A total of 50,438 COVID-19 patients were included in this study and arranged into four exposure groups. Significant additive interaction on post-acute rehospitalization was observed (relative excess risk, 0.10; 95% CI, 0.02-0.19; p-value, 0.018; attributable proportion, 0.07; 95% CI, 0.01-0.12; p-value, 0.017; synergy index, 1.26; 95% CI, 1.02-1.55; p-value, 0.032). The interaction on post-acute mortality was marginally significant. In the subgroup analysis, the interaction effect is more pronounced in older adults, female, and CoronaVac recipients. In conclusion, our study demonstrated an additive interaction between nirmatrelvir-ritonavir and complete vaccination on post-acute outcomes, suggesting greater long-term benefits of the antiviral for fully vaccinated individuals compared to not fully vaccinated patients.

[Post-COVID-19 condition-Clinical phenotyping in practice]

BACKGROUND

The high number and clinical heterogeneity of neurological impairments in patients with a post-COVID-19 condition (PCC) poses a challenge for outpatient care.

OBJECTIVE

Our aim was to evaluate the applicability of the proposed subtypes according to the guidelines "Long/Post-COVID" (30 May 2024) and their phenotyping using clinical and neuropsychological findings from our post-COVID outpatient clinic.

METHODS

The evaluation was based on cross-sectional neurological and psychological test examinations of the patients, which were carried out using standardized questionnaires and test batteries. In addition, a detailed anamnesis of the current symptoms and a retrospective survey of the acute symptoms up to 4 weeks after the confirmed infection was conducted. The subtypes were classified according to the abovementioned guidelines based on the medical history and selected patient questionnaires, to which we added a 5th subtype with reference to the previous guidelines "Long/Post-COVID" (as of 5 March 2023).

RESULTS

A total of 157 patients were included between August 2020 and March 2022. The presentation was at a median of 9.4 months (interquartile range, IQR = 5.3) after infection, with a mean age of 49.9 years (IQR = 17.2) and more women (68%) presenting, with a total hospitalization rate of 26%. Subtype 1 (postintensive care syndrome) showed the highest proportion of men, highest body mass index (BMI) scores and the highest rates of subjective complaints of word-finding difficulties (70%). Subtype 2 (secondary diseases) was dominated by cognitive impairment and had the highest depression scores. Subtype 3 (fatigue and exercise-induced insufficiency) was the most common, had the most symptoms and most severe subjective fatigue and the largest proportion of women. Subtype 4 (exacerbation) mainly showed affective symptoms. Subtype 5 (complaints without relevance to everyday life) had the lowest scores for depression, fatigue and BMI. Neurological and psychological conditions were frequently pre-existing in all groups.

DISCUSSION

The management of PCC can be improved at various levels. A standardized subtype classification enables early individually tailored treatment concepts. Patients at risk should be identified at the primary care level and informed about risk factors and prevention strategies. Regular monitoring of cardiovascular risk factors and physical activity are essential for PCC treatment. In the case of cognitive deficits and concurrent affective symptoms, psychotherapeutic support and drug treatment with selective serotonin reuptake inhibitors (SSRI) should be provided at an early stage.

Pharmacotherapy from Pre-COVID to Post-COVID: Longitudinal Trends and Predictive Indicators for Long COVID Symptoms

BACKGROUND/OBJECTIVES

A significant number of COVID-19 cases experience persistent symptoms after the acute infection phase, a condition known as long COVID or post-acute sequelae of COVID-19. Approved prevention and treatment options for long COVID are currently lacking. Given the heterogeneous nature of long COVID, a personalized medicine approach is essential for effective disease management. This study aimed to describe trends in pharmacotherapy from pre-COVID to post-COVID phases to gain insights into COVID-19 treatment strategies and assess whether pre-COVID pharmacotherapy can predict long COVID symptoms as a health status indicator.

METHODS

In the Precision Medicine for more Oxygen (P4O2) COVID-19 study, 95 long COVID patients were comprehensively evaluated through post-COVID outpatient clinics and study visits. This study focused on descriptive analysis of the pharmacotherapy patterns across different phases: pre-COVID-19, acute COVID, and post-COVID. Furthermore, associations between pre-COVID medication and long COVID outcomes were analyzed with regression analyses.

RESULTS

We observed peaks in the use of certain medications during the acute infection phase, including corticosteroids and antithrombotic agents, with a decrease in the use of renin-angiotensin system inhibitors. Consistently high use of alimentary tract medications was found across all phases. Pre-COVID respiratory medications were associated with fatigue symptoms, while antiinfectives and cardiovascular drugs were linked to fewer persisting long COVID symptom categories.

CONCLUSION

Our findings provide longitudinal, descriptive pharmacotherapy insights and suggest that medication history can be a valuable health status indicator in characterizing patients for personalized disease management strategies, considering the heterogeneous nature of long COVID.

Chronic Viral Reactivation and Associated Host Immune Response and Clinical Outcomes in Acute COVID-19 and Post-Acute Sequelae of COVID-19

Chronic viral infections are ubiquitous in humans, with individuals harboring multiple latent viruses that can reactivate during acute illnesses. Recent studies have suggested that SARS-CoV-2 infection can lead to reactivation of latent viruses such as Epstein-Barr Virus (EBV) and cytomegalovirus (CMV), yet, the extent and impact of viral reactivation in COVID-19 and its effect on the host immune system remain incompletely understood. Here we present a comprehensive multi-omic analysis of viral reactivation of all known chronically infecting viruses in 1,154 hospitalized COVID-19 patients, from the Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) study, who were followed prospectively for twelve months. We reveal significant reactivation of Herpesviridae, Enteroviridae, and Anelloviridae families during acute stage of COVID-19 (0-40 days post-hospitalization), each exhibiting distinct temporal dynamics. We also show that viral reactivation correlated with COVID-19 severity, demographic characteristics, and clinical outcomes, including mortality. Integration of cytokine profiling, cellular immunophenotyping, metabolomics, transcriptomics, and proteomics demonstrated virus-specific host responses, including elevated pro-inflammatory cytokines (e.g. IL-6, CXCL10, and TNF), increased activated CD4+ and CD8+ T-cells, and upregulation of cellular replication genes, independent of COVID-19 severity and SARS-CoV-2 viral load. Notably, persistent Anelloviridae reactivation during convalescence (≥3 months post-hospitalization) was associated with Post-Acute Sequelae of COVID-19 (PASC) symptoms, particularly physical function and fatigue. Our findings highlight a remarkable prevalence and potential impact of chronic viral reactivation on host responses and clinical outcomes during acute COVID-19 and long term PASC sequelae. Our data provide novel immune, transcriptomic, and metabolomic biomarkers of viral reactivation that may inform novel approaches to prognosticate, prevent, or treat acute COVID-19 and PASC.

Symptoms after Lyme disease: What's past is prologue

Protracted fatigue and other symptoms can occur after Lyme disease and other infections, with numerous possible drivers. Studies on posttreatment Lyme disease have been inconclusive, with no confirmed biomarker emerging. Prolonged antibiotic therapy provides no benefit. Thus, a holistic approach toward understanding and treating this complex disease is necessary.

Translating insights into therapies for Long Covid

Long Covid is defined by a wide range of symptoms that persist after the acute phase of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Commonly reported symptoms include fatigue, weakness, postexertional malaise, and cognitive dysfunction, with many other symptoms reported. Symptom range, duration, and severity are highly variable and partially overlap with symptoms of myalgic encephalomyelitis/chronic fatigue syndrome and other post-acute infectious syndromes, highlighting opportunities to define shared mechanisms of pathogenesis. Potential mechanisms of Long Covid are diverse, including persistence of viral reservoirs, dysregulated immune responses, direct viral damage of tissues targeted by SARS-CoV-2, inflammation driven by reactivation of latent viral infections, vascular endothelium activation or dysfunction, and subsequent thromboinflammation, autoimmunity, metabolic derangements, microglial activation, and microbiota dysbiosis. The heterogeneity of symptoms and baseline characteristics of people with Long Covid, as well as the varying states of immunity and therapies given at the time of acute infection, have made etiologies of Long Covid difficult to determine. Here, we examine progress on preclinical models for Long Covid and review progress being made in clinical trials, highlighting the need for large human studies and further development of models to better understand Long Covid. Such studies will inform clinical trials that will define treatments to benefit those living with this condition.

Burden of post-acute COVID-19 sequelae in healthcare workers and its course over a 30-month period-results from a prospective multicentre cohort

PURPOSE

As healthcare workers (HCW) have been disproportionally affected by COVID-19, its post-acute sequelae (PASC) in HCW can impact healthcare systems. We assessed the burden and course of PASC in HCW over a 30-month period.

METHODS

In a prospective multicentre HCW cohort in Switzerland, PASC surveys were conducted in 03/2021, 09/2021, 06/2022, 04/2023, and 10/2023. Stratified by viral variant at first infection, the prevalence of PASC symptoms, self-experienced PASC and the Post-COVID Functional Status (PCFS) were analysed cross-sectionally in 10/2023, self-perceived success of therapeutic measures used was assessed. The evolution of PASC symptoms and PCFS in Wild-type and non-Wild-type infected HCW compared to uninfected controls was analysed longitudinally across all surveys.

RESULTS

In cross-sectional analysis, 1704 HCW (median age 47 years, 82.2% female) were included. Thereof, 30.7% reported ≥ 1 PASC symptom in 10/2023, with 115 (6.7%) stating to have or have had PASC. Both were most common after Wild-type infection compared to other variants. Overall, 17/115 (15%) indicated relevant/severe restrictions in their daily activities and of 85 (74%) that tried ≥ 1 measure against their symptoms, 69 (81%) reported having benefitted. Longitudinal analysis (n = 653) showed a significantly higher proportion of Wild-type infected HCW to report PASC symptoms compared to controls in 03/2021 (+ 21%, 95% CI 4-39), with decreasing trend (+ 7%, 95%CI -10-25 in 10/2023). This effect was not evident for non-Wild-type infected HCW.

CONCLUSIONS

Over a 30 month period, overall PASC burden in our HCW cohort decreased, although 1% still experience relevant restrictions in their daily life; Wild-type infected individuals show the highest disease burden.

Physical, cognitive, and social triggers of symptom fluctuations in people living with long COVID: an intensive longitudinal cohort study

Background

Symptom fluctuations within and between individuals with long COVID are widely reported, but the extent to which severity varies following different types of activity and levels of exertion, and the timing of symptoms and recovery, have not previously been quantified. We aimed to characterise timing, severity, and nature of symptom fluctuations in response to effortful physical, social and cognitive activities, using Ecological Momentary Assessments.

Methods

We recorded activity, effort, and severity of 8 core symptoms every 3 h for up to 24 days, in cohorts from both clinic and community settings. Symptom severities were jointly modelled using autoregressive and moving average processes.

Findings

Consent was received from 376 participants providing ≥1 week's measurements (273 clinic-based, 103 community-based). Severity of all symptoms was elevated 30 min after all categories of activity. Increased effort was associated with increased symptom severity. Fatigue severity scores increased by 1.8/10 (95% CI: 1.6-1.9) following the highest physical exertions and by 1.5 (1.4-1.7) following cognitive efforts. There was evidence of only mild delayed fatigue 3 h (0.3, 0.2-0.5) or one day later (0.2, 0.0- 0.5). Fatigue severity increased as the day progressed (1.4, 1.0-1.7), and cognitive dysfunction was 0.2 lower at weekends (0.1-0.3).

Interpretation

Cognitive, social, self-care and physical activities all triggered increased severity across every symptom, consistent with associated common pathways as potential therapeutic targets. Clear patterns of symptom fluctuations emerged that support more targeted self-management.

Funding

National Institute for Health and Care Research.

Immune response in vaccinated healthcare workers with frequent COVID-19 infections is characterised by blunted IFNγ and IL-2 responses to SARS-CoV-2 variants

Healthcare workers (HCWs) are at increased risk of SARS-CoV-2 infection. Despite widespread vaccination, some HCWs develop frequent symptomatic infection. We hypothesised that HCWs with frequent symptomatic COVID-19 have impaired T and B cell mediated immunity to SARS-CoV-2. Vaccinated HCWs with no prior COVID infection (n = 9), asymptomatic recent infection (n = 10), and frequent recent infection (n = 15) were recruited from a longitudinal HCW cohort study. Whole blood stimulation with SARS-CoV-2 variants (Wuhan, B.1.617, BA.2, BA.2.75, BA.4/5, XBB.1.5, BQ.1.1) was performed, with IFNγ and IL-2 responses, total IgG produced, and anti-Spike antibody neutralising capacity measured. Frequent infections had similar IFNγ and IL-2 responses to the never infected group, with significantly higher responses in the asymptomatic group. The frequent cohort had higher IgG responses to Delta and BA.4/5 and higher neutralising capacity against Omicron variants. An immune signature of blunted IL-2 and IFNγ in frequent infections may identify HCWs at increased risk of further infection.

Long Covid: a global health issue - a prospective, cohort study set in four continents

INTRODUCTION

A proportion of people develop Long Covid after acute COVID-19, but with most studies concentrated in high-income countries (HICs), the global burden is largely unknown. Our study aims to characterise long-term COVID-19 sequelae in populations globally and compare the prevalence of reported symptoms in HICs and low-income and middle-income countries (LMICs).

METHODS

A prospective, observational study in 17 countries in Africa, Asia, Europe and South America, including adults with confirmed COVID-19 assessed at 2 to <6 and 6 to <12 months post-hospital discharge. A standardised case report form developed by International Severe Acute Respiratory and emerging Infection Consortium's Global COVID-19 Follow-up working group evaluated the frequency of fever, persistent symptoms, breathlessness (MRC dyspnoea scale), fatigue and impact on daily activities.

RESULTS

Of 11 860 participants (median age: 52 (IQR: 41-62) years; 52.1% females), 56.5% were from HICs and 43.5% were from LMICs. The proportion identified with Long Covid was significantly higher in HICs vs LMICs at both assessment time points (69.0% vs 45.3%, p<0.001; 69.7% vs 42.4%, p<0.001). Participants in HICs were more likely to report not feeling fully recovered (54.3% vs 18.0%, p<0.001; 56.8% vs 40.1%, p<0.001), fatigue (42.9% vs 27.9%, p<0.001; 41.6% vs 27.9%, p<0.001), new/persistent fever (19.6% vs 2.1%, p<0.001; 20.3% vs 2.0%, p<0.001) and have a higher prevalence of anxiety/depression and impact on usual activities compared with participants in LMICs at 2 to <6 and 6 to <12 months post-COVID-19 hospital discharge, respectively.

CONCLUSION

Our data show that Long Covid affects populations globally, manifesting similar symptomatology and impact on functioning in both HIC and LMICs. The prevalence was higher in HICs versus LMICs. Although we identified a lower prevalence, the impact of Long Covid may be greater in LMICs if there is a lack of support systems available in HICs. Further research into the aetiology of Long Covid and the burden in LMICs is critical to implement effective, accessible treatment and support strategies to improve COVID-19 outcomes for all.

Prepandemic Metabolic Correlates of Coronavirus Disease 2019 (COVID-19) Severity and Long COVID Incidence in People Living With HIV

Host metabolic dysregulation, especially in tryptophan metabolism, is intricately linked to coronavirus disease 2019 (COVID-19) severity and its postacute sequelae (long COVID). People living with human immunodeficiency virus (HIV; PLWH) experience similar metabolic dysregulation and face an increased risk of developing long COVID. However, whether preexisting HIV-associated metabolic dysregulations contribute in predisposing PLWH to severe COVID-19 outcomes remains underexplored. Analyzing prepandemic samples from PLWH with documented postinfection outcomes, we found specific metabolic alterations, including increased tryptophan catabolism, predicting an elevated risk of severe COVID-19 and the incidence of long COVID. These alterations warrant further investigation for their potential prognostic and mechanistic significance in determining COVID-19 complications.

Implications of frailty before and after intensive care unit admission

PURPOSE OF REVIEW

In the decade since the first publications related to frailty in those with critical illness, the study of frailty has rapidly increased. The purpose of this review is to update the reader on recent advances across several important areas of frailty research: how best to identify frailty in those with critical illness, studies describing the relationship between frailty and delirium, and how frailty affects outcomes for those with coronavirus disease 2019 (COVID-19), which, despite rates and severity of acute infection declining, still tremendously impacts patients long after the acute infection, resulting in symptoms of long COVID-19.

RECENT FINDINGS

A number of frailty assessment tools exist, to date, the Clinical Frailty Scale based on the deficit accumulation approach to defining frailty, is the most commonly used in ICU studies. Several novel frailty instruments for the ICU are being developed. Because tools assessing frailty by the phenotypic and deficit accumulation approaches identify different populations, careful choice of a frailty assessment tool is warranted.Frailty and delirium are hypothesized to represent different clinical expressions of a similar underlying vulnerability, thus identifying frailty may be a useful means by which to identify patients at high risk of becoming delirious. Recent studies show that frailty at ICU admission is a predictor of the development of delirium.Finally, frailty and its outcomes were studied in patients with COVID-19. As with other causes of critical illness, frailty was highly prevalent in those admitted to the ICU and is associated with greater mortality. Frailty was also associated with increased decisions to limit life support treatments, but these decisions were not different among those admitted with COVID-19 or for other reasons.

SUMMARY

Frailty in those with critical illness is an emerging field of study. Future work to define the optimal means by which to identify this syndrome and how best to manage critically ill patients with frailty are needed.

Long-term effects of the COVID-19 pandemic for patients with cancer

INTRODUCTION

Long COVID is defined as the continuation of symptoms, unexplainable by alternative diagnosis, longer than four weeks after SARS-CoV-2 infection. These symptoms might hinder daily activities and overall well-being, ultimately impacting quality of life (QoL). Several studies have reported fatigue as the most common symptom, followed by dyspnoea, headache and myalgia. Although it is assumed that long COVID affects 10-20% of SARS-CoV-2 infected individuals, recently numbers up to 60% were described for patients with cancer. This study uncovers the impact of the COVID-19 pandemic on QoL of patients with cancer and how long COVID manifests in this cohort.

METHODS

A group of 96 patients with cancer was followed from March 2022 till March 2023. Online questionnaires assessing symptoms associated with long COVID, anxiety and depression (HADS), quality of life (EORTC-QLQ-C30) and cognitive functioning (CFQ) were sent every three months during this period. Furthermore, a semi-structured focus group was organised for qualitative data collection.

RESULTS

Overall, these patients reported a negative impact of the enforced COVID-19 restrictions on the emotional and psychological wellbeing. Forty nine patients with cancer (51.0%) were infected with SARS-CoV-2 over the course of the study, of which 39 (79.6%) reported long COVID symptoms. The most commonly reported symptoms were myalgia (46.2%), fatigue (38.5%) and disturbed sleep (35.9%) and it was observed that male sex is associated with poor long COVID outcomes.

CONCLUSION

While patients with cancer experience similar long COVID symptoms as healthy controls, the prevalence is remarkably higher possibly due to their compromised immune system and weakened physiological reserve.

A pilot randomized controlled trial of major ozone autohemotherapy for patients with post-acute sequelae of COVID-19

This prospective, randomized, controlled clinical trial assessed the therapeutic effects of major ozone autohemotherapy (O3-MAH) in patients with post-acute sequelae of COVID-19 (PASC). Seventy-three eligible participants were randomly assigned to an O3-MAH plus conventional therapy group (n = 35) or a conventional therapy alone group (n = 38). Symptom score, pulmonary function, 6-minute walk distance (6MWD), and hematological, biochemical, and immunological parameters were evaluated before and after the interventions. Both groups demonstrated improvements in various parameters post-intervention, but efficacy was greater in the O3-MAH group than the conventional treatment group; with intervention effectiveness defined as a ≥ 50 % reduction in symptom score, 25 of 35 patients (71 %) responded to O3-MAH, while 17/38 patients (45 %) responded to conventional treatment alone (P = 0.0325). Significant improvements in symptom scores (P = 0.0478), tidal volume (P = 0.0374), predicted 6MWD (P = 0.0032), and coagulation and inflammatory indicators were noted in the O3-MAH group compared with the conventional treatment group. O3-MAH was more likely to be effective in patients with elevated CRP levels. Furthermore, O3-MAH markedly improved cellular immunity, and this improvement became more pronounced with extended treatment duration. In summary, combining O3-MAH with conventional treatment was more effective than conventional therapy alone in improving symptoms, pulmonary function, inflammation, coagulation, and cellular immunity in patients with PASC. Further research is now warranted to validate these findings and individualize the regimen.

Long COVID demographic and secondary care referral characteristics in primary care: analysis of anonymised primary care data from a multiethnic, deprived urban area in the UK

Once the nature and number of patients with Long COVID was more fully understood, UK secondary care developed services to investigate, treat and support these patients. We aimed to identify evidence for demographic health inequalities based on general practitioner (GP) Long COVID referrals to available secondary care services. Despite Long COVID demographics broadly reflecting the multiethnic and socially disadvantaged profile of the study population, we found that secondary care referral was mainly focussed on older age patients and those born in the UK with co-morbid anxiety; although co-morbid diabetes was associated with reduced referrals.

Understanding the mechanisms and treatments of long COVID to address future public health risks

The 2019 coronavirus disease (COVID-19), triggered by the severe acute respiratory syndrome coronavirus (SARS-CoV-2), has seen numerous individuals undergo and recover from it, drawing extensive attention to their health conditions. Extensive studies indicate that even after surpassing the acute phase of infection, patients continue to experience persistent symptoms such as fatigue, pain, depression, weakening, and anosmia. COVID-19 appears not to have concluded but rather to persist long-term in certain individuals, termed as "long COVID." This represents a heterogeneous ailment involving multiple organ systems, with a perceived complex and still elusive pathogenesis. Among patients with long COVID, observations reveal immune dysregulation, coagulation impairments, and microbial dysbiosis, considered potential mechanisms explaining sustained adverse outcomes post COVID-19. Based on the multifactorial nature, varied symptoms, and heterogeneity of long COVID, we have summarized several categories of current therapeutic approaches. Furthermore, the symptoms of long COVID resemble those of other viral illnesses, suggesting that existing knowledge may offer novel insights into long-term COVID implications. Here, we provide an overview of existing literature associated with long COVID and summarize potential mechanisms, treatment modalities, and other analogous conditions. Lastly, we underscore the inadequacies in long COVID treatment approaches and emphasize the significance of conducting further research and clinical trials.

Improving quality in adult long covid services: Findings from the LOCOMOTION quality improvement collaborative

The protracted form of COVID-19 known as 'long covid' was first described in 2020. Its symptoms, course and prognosis vary widely; some patients have a multi-system, disabling and prolonged illness. In 2021, ring-fenced funding was provided to establish 90 long covid clinics in England; some clinics were also established in Scotland and Wales. The NIHR-funded LOCOMOTION project implemented a UK-wide quality improvement collaborative involving ten of these clinics, which ran from 2021 to 2023. At regular online meetings held approximately 8-weekly, participants prioritised topics, discussed research evidence and guidelines, and presented exemplar case histories and clinic audits. A patient advisory group also held a priority-setting exercise, participated in quality meetings and undertook a service evaluation audit. The goal of successive quality improvement cycles aimed at changing practice to align with evidence was sometimes hard to achieve because definitive evidence did not yet exist in this new condition; many patients had comorbidities; and clinics were practically constrained in various ways. Nevertheless, much progress was made and a series of 'best practice' guides was produced, covering general assessment and management; breathing difficulties; orthostatic tachycardia and other autonomic symptoms; fatigue and cognitive impairment; and vocational rehabilitation. This paper summarises key findings with the frontline clinician in mind.

Long COVID as a disease of accelerated biological aging: An opportunity to translate geroscience interventions

It has been four years since long COVID-the protracted consequences that survivors of COVID-19 face-was first described. Yet, this entity continues to devastate the quality of life of an increasing number of COVID-19 survivors without any approved therapy and a paucity of clinical trials addressing its biological root causes. Notably, many of the symptoms of long COVID are typically seen with advancing age. Leveraging this similarity, we posit that Geroscience-which aims to target the biological drivers of aging to prevent age-associated conditions as a group-could offer promising therapeutic avenues for long COVID. Bearing this in mind, this review presents a translational framework for studying long COVID as a state of effectively accelerated biological aging, identifying research gaps and offering recommendations for future preclinical and clinical studies.

Impact of age and sex on neuroinflammation following SARS-CoV-2 infection in a murine model

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, is known to infect people of all ages and both sexes. Senior populations have the greatest risk of severe COVID-19, and sexual dimorphism in clinical outcomes has been reported. Neurological symptoms are widely observed in COVID-19 patients, with many survivors exhibiting persistent neurological and cognitive impairment. The present study aims to investigate the impact of age and sex on the neuroinflammatory response to SARS-CoV-2 infection using a mouse model. Wild-type C57BL/6J mice were intranasally inoculated with SARS-CoV-2 lineage B.1.351, a variant known to infect mice. Older male mice exhibited a significantly greater weight loss and higher viral loads in the lung at 3 days post infection. Notably, no viral RNA was detected in the brains of infected mice. Nevertheless, expression of IL-6, TNF-α, and CCL-2 in the lung and brain increased with viral infection. RNA-seq transcriptomic analysis of brains showed that SARS-CoV-2 infection caused significant changes in gene expression profiles, implicating innate immunity, defense response to virus, and cerebrovascular and neuronal functions. These findings demonstrate that SARS-CoV-2 infection triggers a neuroinflammatory response, despite the lack of detectable virus in the brain. Aberrant activation of innate immune response, disruption of blood-brain barrier and endothelial cell integrity, and suppression of neuronal activity and axonogenesis underlie the impact of SARS-CoV-2 infection on the brain. Understanding the role of these affected pathways in SARS-CoV-2 pathogenesis helps identify appropriate points of therapeutic interventions to alleviate neurological dysfunction observed during COVID-19.

Post-COVID syndrome prevalence: a systematic review and meta-analysis

BACKGROUND

Since the Coronavirus disease 2019 (COVID-19) pandemic began, the number of individuals recovering from COVID-19 infection have increased. Post-COVID Syndrome, or PCS, which is defined as signs and symptoms that develop during or after infection in line with COVID-19, continue beyond 12 weeks, and are not explained by an alternative diagnosis, has also gained attention. We systematically reviewed and determined the pooled prevalence estimate of PCS worldwide based on published literature.

METHODS

Relevant articles from the Web of Science, Scopus, PubMed, Cochrane Library, and Ovid MEDLINE databases were screened using a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided systematic search process. The included studies were in English, published from January 2020 to April 2024, had overall PCS prevalence as one of the outcomes studied, involved a human population with confirmed COVID-19 diagnosis and undergone assessment at 12 weeks post-COVID infection or beyond. As the primary outcome measured, the pooled prevalence of PCS was estimated from a meta-analysis of the PCS prevalence data extracted from individual studies, which was conducted via the random-effects model. This study has been registered on PROSPERO (CRD42023435280).

RESULTS

Forty eight studies met the eligibility criteria and were included in this review. 16 were accepted for meta-analysis to estimate the pooled prevalence for PCS worldwide, which was 41.79% (95% confidence interval [CI] 39.70-43.88%, I2 = 51%, p = 0.03). Based on different assessment or follow-up timepoints after acute COVID-19 infection, PCS prevalence estimated at ≥ 3rd, ≥ 6th, and ≥ 12th months timepoints were each 45.06% (95% CI: 41.25-48.87%), 41.30% (95% CI: 34.37-48.24%), and 41.32% (95% CI: 39.27-43.37%), respectively. Sex-stratified PCS prevalence was estimated at 47.23% (95% CI: 44.03-50.42%) in male and 52.77% (95% CI: 49.58-55.97%) in female. Based on continental regions, pooled PCS prevalence was estimated at 46.28% (95% CI: 39.53%-53.03%) in Europe, 46.29% (95% CI: 35.82%-56.77%) in America, 49.79% (95% CI: 30.05%-69.54%) in Asia, and 42.41% (95% CI: 0.00%-90.06%) in Australia.

CONCLUSION

The prevalence estimates in this meta-analysis could be used in further comprehensive studies on PCS, which might enable the development of better PCS management plans to reduce the effect of PCS on population health and the related economic burden.

Imbalance of SARS-CoV-2-specific CCR6+ and CXCR3+ CD4+ T cells and IFN-γ + CD8+ T cells in patients with Long-COVID

Long-COVID (LC) is characterised by persistent symptoms for at least 3 months after acute infection. A dysregulation of the immune system and a persistent hyperinflammatory state may cause LC. LC patients present differences in activation and exhaustion states of innate and adaptive compartments. Different T CD4+ cell subsets can be identified by differential expression of chemokine receptors (CCR). However, changes in T cells with expression of CCRs such as CCR6 and CXCR3 and their relationship with CD8+ T cells remains unexplored in LC. Here, we performed unsupervised analysis and found CCR6+ CD4+ subpopulations enriched in COVID-19 convalescent individuals upon activation with SARS-CoV-2 peptides. SARS-CoV-2 specific CCR6+ CD4+ are decreased in LC patients, whereas CXCR3+ CCR6- and CCR4+ CCR6- CD4+ T cells are increased. LC patients showed lower IFN-γ-secreting CD8+ T cells after stimulation with SARS-CoV-2 Spike protein. This work underscores the role of CCR6 in the pathophysiology of LC.

Exploring the Complexities of Long COVID

Since the emergence of the SARS-CoV-2 virus in 2019, nearly 700 million COVID-19 cases and 7 million deaths have been reported globally. Despite most individuals recovering within four weeks, the Center for Disease Control (CDC) estimates that 7.5% to 41% develop post-acute infection syndrome (PAIS), known as 'Long COVID'. This review provides current statistics on Long COVID's prevalence, explores hypotheses concerning epidemiological factors, such as age, gender, comorbidities, initial COVID-19 severity, and vaccine interactions, and delves into potential mechanisms, including immune responses, viral persistence, and gut dysbiosis. Moreover, we conclude that women, advanced age, comorbidities, non-vaccination, and low socioeconomic status all appear to be risk factors. The reasons for these differences are still not fully understood and likely involve a complex relationship between social, genetic, hormonal, and other factors. Furthermore, individuals with Long COVID-19 seem more likely to endure economic hardship due to persistent symptoms. In summary, our findings further illustrate the multifaceted nature of Long COVID and underscore the importance of understanding the epidemiological factors and potential mechanisms needed to develop effective therapeutic strategies and interventions.

Evaluation of Novel Nasal Mucoadhesive Nanoformulations Containing Lipid-Soluble EGCG for Long COVID Treatment

Following recovery from the acute infection stage of the SARS-CoV-2 virus (COVID-19), survivors can experience a wide range of persistent Post-Acute Sequelae of COVID-19 (PASC), also referred to as long COVID. According to the US National Research Action Plan on Long COVID 2022, up to 23.7 million Americans suffer from long COVID, and approximately one million workers may be out of the workforce each day due to these symptoms, leading to a USD 50 billion annual loss of salary. Neurological symptoms associated with long COVID result from persistent infection with SARS-CoV-2 in the nasal neuroepithelial cells, leading to inflammation in the central nervous system (CNS). As of today, there is no evidence that vaccines or medications can clear the persistent viral infection in olfactory mucosa. Recently published clinical data demonstrate that only 5% of long COVID anosmia patients have fully recovered during the past 2 years, and 10.4% of COVID patients are still symptomatic 18 months post-infection. Our group demonstrated that epigallocatechin-3-gallate-monopalmitate (EC16m) nanoformulations possess strong antiviral activity against human coronavirus, suggesting that this green-tea-derived compound in nanoparticle formulations could be developed as an intranasally delivered new drug targeting the persistent SARS-CoV-2 infection, as well as inflammation and oxidative stress in the CNS, leading to restoration of neurologic functions. The objective of the current study was to evaluate the mucociliary safety of the EC16m nasal nanoformulations and their efficacy against human coronavirus.

METHODS

Nanoparticle size and Zeta potential were measured using the ZetaView Nanoparticle Tracking Analysis system; mucociliary safety was determined using the MucilAir human nasal model; contact antiviral activity and post-infection inhibition against the OC43 viral strain were assessed by the TCID50 assay for cytopathic effect on MRC-5 cells.

RESULTS

The saline-based EC16 mucoadhesive nanoformulations containing 0.005 to 0.02% w/v EC16m have no significant difference compared to saline (0.9% NaCl) with respect to tissue integrity, cytotoxicity, and cilia beat frequency. A 5 min contact resulted in 99.9% inactivation of β-coronavirus OC43. OC43 viral replication was inhibited by >90% after infected MRC-5 cells were treated with the formulations.

CONCLUSION

The saline-based novel EC16m mucoadhesive nasal nanoformulations rapidly inactivated human coronavirus with mucociliary safety properties comparable to saline, a solution widely used for nasal applications.

Growth Differentiation Factor-15 Is Considered a Predictive Biomarker of Long COVID in Non-hospitalized Patients

Mitochondrial dysfunction is associated with various diseases. Mitochondria plays a regulatory role during infection. The association between mitokines and subsequent COVID progression has not been previously studied. The retrospective cohort study aimed to investigate the potential of serum mitokines as long COVID biomarkers in non-hospitalized patients. Patients with confirmed SARS-CoV-2 infection and blood test reports between January 2021 and April 2023 were included. Patients were categorized into two groups, the recovered and long COVID groups, based on fatigue, decline in focus, and pain. Serum levels of growth differentiation factor 15 (GDF-15) and fibroblast growth factor-21 (FGF-21), which are affected by mitochondrial function, along with inflammatory and vascular endothelium markers, were measured using enzyme-linked immunosorbent assays (ELISA). A receiver operating characteristic curve was used to screen the biomarkers. The threshold value of GDF-15 in the acute phase was 965 pg/mL (sensitivity: 71.4%, specificity: 83.3%), indicating that GDF-15 may be associated with the presence of symptoms three months post onset. No association with inflammatory markers and vascular structures was observed. Therefore, elevated GDF-15 levels in the acute phase may act as a predictive biomarker of long COVID.

Long COVID incidence in adults and children between 2020 and 2023: a real-world data study from the RECOVER Initiative

Estimates of post-acute sequelae of SARS-CoV-2 infection (PASC) incidence, also known as Long COVID, have varied across studies and changed over time. We estimated PASC incidence among adult and pediatric populations in three nationwide research networks of electronic health records (EHR) participating in the RECOVER Initiative using different classification algorithms (computable phenotypes). Overall, 7% of children and 8.5%-26.4% of adults developed PASC, depending on computable phenotype used. Excess incidence among SARS-CoV-2 patients was 4% in children and ranged from 4-7% among adults, representing a lower-bound incidence estimation based on two control groups - contemporary COVID-19 negative and historical patients (2019). Temporal patterns were consistent across networks, with peaks associated with introduction of new viral variants. Our findings indicate that preventing and mitigating Long COVID remains a public health priority. Examining temporal patterns and risk factors of PASC incidence informs our understanding of etiology and can improve prevention and management.

Alterations in microbiota of patients with COVID-19: implications for therapeutic interventions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently caused a global pandemic, resulting in more than 702 million people being infected and over 6.9 million deaths. Patients with coronavirus disease (COVID-19) may suffer from diarrhea, sleep disorders, depression, and even cognitive impairment, which is associated with long COVID during recovery. However, there remains no consensus on effective treatment methods. Studies have found that patients with COVID-19 have alterations in microbiota and their metabolites, particularly in the gut, which may be involved in the regulation of immune responses. Consumption of probiotics may alleviate the discomfort caused by inflammation and oxidative stress. However, the pathophysiological process underlying the alleviation of COVID-19-related symptoms and complications by targeting the microbiota remains unclear. In the current study, we summarize the latest research and evidence on the COVID-19 pandemic, together with symptoms of SARS-CoV-2 and vaccine use, with a focus on the relationship between microbiota alterations and COVID-19-related symptoms and vaccine use. This work provides evidence that probiotic-based interventions may improve COVID-19 symptoms by regulating gut microbiota and systemic immunity. Probiotics may also be used as adjuvants to improve vaccine efficacy.

Systems analysis of innate and adaptive immunity in Long COVID

Since the onset of the COVID-19 pandemic, significant progress has been made in developing effective preventive and therapeutic strategies against severe acute SARS-CoV-2 infection. However, the management of Long COVID (LC), an infection-associated chronic condition that has been estimated to affect 5-20% of individuals following SARS-CoV-2 infection, remains challenging due to our limited understanding of its mechanisms. Although LC is a heterogeneous disease that is likely to have several subtypes, immune system disturbances appear common across many cases. The extent to which these immune perturbations contribute to LC symptoms, however, is not entirely clear. Recent advancements in multi-omics technologies, capable of detailed, cell-level analysis, have provided valuable insights into the immune perturbations associated with LC. Although these studies are largely descriptive in nature, they are the crucial first step towards a deeper understanding of the condition and the immune system's role in its development, progression, and resolution. In this review, we summarize the current understanding of immune perturbations in LC, covering both innate and adaptive immune responses, and the cytokines and analytes involved. We explore whether these findings support or challenge the primary hypotheses about LC's underlying mechanisms. We also discuss the crosstalk between various immune system components and how it can be disrupted in LC. Finally, we emphasize the need for more tissue- and subtype-focused analyses of LC, and for enhanced collaborative efforts to analyze common specimens from large cohorts, including those undergoing therapeutic interventions. These collective efforts are vital to unravel the fundaments of this new disease, and could also shed light on the prevention and treatment of the larger family of chronic illnesses linked to other microbial infections.

Long-Term Autoimmune Inflammatory Rheumatic Outcomes of COVID-19 : A Binational Cohort Study

BACKGROUND

Some data suggest a higher incidence of diagnosis of autoimmune inflammatory rheumatic diseases (AIRDs) among patients with a history of COVID-19 compared with uninfected patients. However, these studies had methodological shortcomings.

OBJECTIVE

To investigate the effect of COVID-19 on long-term risk for incident AIRD over various follow-up periods.

DESIGN

Binational, longitudinal, propensity-matched cohort study.

SETTING

Nationwide claims-based databases in South Korea (K-COV-N cohort) and Japan (JMDC cohort).

PARTICIPANTS

10 027 506 Korean and 12 218 680 Japanese patients aged 20 years or older, including those with COVID-19 between 1 January 2020 and 31 December 2021, matched to patients with influenza infection and to uninfected control patients.

MEASUREMENTS

The primary outcome was onset of AIRD (per appropriate codes from the International Classification of Diseases, 10th Revision) 1, 6, and 12 months after COVID-19 or influenza infection or the respective matched index date of uninfected control patients.

RESULTS

Between 2020 and 2021, among the 10 027 506 Korean participants (mean age, 48.4 years [SD, 13.4]; 50.1% men), 394 274 (3.9%) and 98 596 (0.98%) had a history of COVID-19 or influenza, respectively. After propensity score matching, beyond the first 30 days after infection, patients with COVID-19 were at increased risk for incident AIRD compared with uninfected patients (adjusted hazard ratio, 1.25 [95% CI, 1.18 to 1.31]) and influenza-infected control patients (adjusted hazard ratio, 1.30 [CI, 1.02 to 1.59]). The risk for incident AIRD was higher with more severe acute COVID-19. Similar patterns were observed in the Japanese cohort.

LIMITATIONS

Referral bias due to the pandemic; residual confounding.

CONCLUSION

SARS-CoV-2 infection was associated with increased risk for incident AIRD compared with matched patients without SARS-CoV-2 infection or with influenza infection. The risk for incident AIRD was higher with greater severity of acute COVID-19.

PRIMARY FUNDING SOURCE

National Research Foundation of Korea.