Persistent symptoms up to four months after community and hospital-managed SARS-CoV-2 infection

The roles of the kynurenine pathway in COVID-19 neuropathogenesis

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the highly contagious respiratory disease Corona Virus Disease 2019 (COVID-19) that may lead to various neurological and psychological disorders that can be acute, lasting days to weeks or months and possibly longer. The latter is known as long-COVID or more recently post-acute sequelae of COVID (PASC). During acute COVID-19 infection, a strong inflammatory response, known as the cytokine storm, occurs in some patients. The levels of interferon-γ (IFN-γ), interferon-β (IFN-β), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) are particularly increased. These cytokines are known to activate the enzyme indoleamine 2,3-dioxygenase 1 (IDO-1), catalysing the first step of tryptophan (Trp) catabolism through the kynurenine pathway (KP) leading to the production of several neurotoxic and immunosuppressive metabolites. There is already data showing elevation in KP metabolites both acutely and in PASC, especially regarding cognitive impairment. Thus, it is likely that KP involvement is significant in SARS-CoV-2 pathogenesis especially neurologically.

Psychiatric sequelae after SARS-Cov-2 infection: trajectory, predictors and associations in a longitudinal Australian cohort

A relationship between SARS-CoV-2 infection and psychiatric symptoms has been identified but is still being fully investigated. Neuropsychiatric sequalae have been reported for several infectious agents and are not unexpected for SARS-CoV-2 infection. This study follows for 12 months a sample (N = 144) of people who have had a confirmed infection of SARS-CoV-2. Medical and neuropsychiatric data and biological specimens are collected at 6 study visits. The 34-item SPHERE questionnaire, the Depression in the Medically Ill instrument, the EQ-5D-5L quality of life instrument and the visual analogue scale of fatigue were administered at multiple timepoints and associations with measures of illness and inflammatory biomarkers were investigated using the generalised estimating equation. Associations between inflammatory biomarkers and mental health measures of various effect sizes were identified. A robust inverse association was found between mental health outcomes and long covid status, but not between mental health outcomes and covid illness severity. This study suggests that long covid may be the strongest predictor of neuropsychiatric symptoms amongst people who have been infected with SARS-CoV-2.

Improvement of immune dysregulation in individuals with long COVID at 24-months following SARS-CoV-2 infection

This study investigates the humoral and cellular immune responses and health-related quality of life measures in individuals with mild to moderate long COVID (LC) compared to age and gender matched recovered COVID-19 controls (MC) over 24 months. LC participants show elevated nucleocapsid IgG levels at 3 months, and higher neutralizing capacity up to 8 months post-infection. Increased spike-specific and nucleocapsid-specific CD4+ T cells, PD-1, and TIM-3 expression on CD4+ and CD8+ T cells were observed at 3 and 8 months, but these differences do not persist at 24 months. Some LC participants had detectable IFN-γ and IFN-β, that was attributed to reinfection and antigen re-exposure. Single-cell RNA sequencing at the 24 month timepoint shows similar immune cell proportions and reconstitution of naïve T and B cell subsets in LC and MC. No significant differences in exhaustion scores or antigen-specific T cell clones are observed. These findings suggest resolution of immune activation in LC and return to comparable immune responses between LC and MC over time. Improvement in self-reported health-related quality of life at 24 months was also evident in the majority of LC (62%). PTX3, CRP levels and platelet count are associated with improvements in health-related quality of life.

Cognitive decline in older adults in the UK during and after the COVID-19 pandemic: a longitudinal analysis of PROTECT study data

BACKGROUND

Although the long-term health effects of COVID-19 are increasingly recognised, the societal restrictions during the COVID-19 pandemic hold the potential for considerable detriment to cognitive and mental health, particularly because major dementia risk factors-such as those related to exercise and dietary habits-were affected during this period. We used longitudinal data from the PROTECT study to evaluate the effect of the pandemic on cognition in older adults in the UK.

METHODS

For this longitudinal analysis, we used computerised neuropsychology data from individuals aged 50 years and older participating in the PROTECT study in the UK. Data were collected from the same participants before the COVID-19 pandemic (March 1, 2019-Feb 29, 2020) and during its first (March 1, 2020-Feb 28, 2021) and second (March 1, 2021-Feb 28, 2022) years. We compared cognition across the three time periods using a linear mixed-effects model. Subgroup analyses were conducted in people with mild cognitive impairment and in people who reported a history of COVID-19, and an exploratory regression analysis identified factors associated with changes in cognitive trajectory.

FINDINGS

Pre-pandemic data were included for 3142 participants, of whom 1696 (54·0%) were women and 1446 (46·0%) were men, with a mean age of 67·5 years (SD 9·6, range 50-96). Significant worsening of executive function and working memory was observed in the first year of the pandemic across the whole cohort (effect size 0·15 [95% CI 0·12-0·17] for executive function and 0·51 [0·49-0·53] for working memory), in people with mild cognitive impairment (0·13 [0·07-0·20] and 0·40 [0·36-0·47]), and in people with a history of COVID-19 (0·24 [0·16-0·31] and 0·46 [0·39-0·53]). Worsening of working memory was sustained across the whole cohort in the second year of the pandemic (0·47; 0·44-0·49). Regression analysis indicated that cognitive decline was significantly associated with reduced exercise (p=0·0049; executive function) and increased alcohol use (p=0·049; working memory) across the whole cohort, as well as depression (p=0·011; working memory) in those with a history of COVID-19 and loneliness (p=0·0038; working memory) in those with mild cognitive impairment. In the second year of the pandemic, reduced exercise continued to affect executive function across the whole cohort, and associations were sustained between worsening working memory and increased alcohol use (p=0·0040), loneliness (p=0·042), and depression (p=0·014) in those with mild cognitive impairment, and reduced exercise (p=0·0029), loneliness (p=0·031) and depression (p=0·036) in those with a history of COVID-19.

INTERPRETATION

The COVID-19 pandemic resulted in a significant worsening of cognition in older adults, associated with changes in known dementia risk factors. The sustained decline in cognition highlights the need for public health interventions to mitigate the risk of dementia-particularly in people with mild cognitive impairment, in whom conversion to dementia within 5 years is a substantial risk. Long-term intervention for people with a history of COVID-19 should be considered to support cognitive health.

FUNDING

National Institute for Health and Care Research.

Treatable traits for long COVID

Long COVID, or post-acute COVID-19 sequelae, is experienced by an estimated one in eight adults following acute COVID-19. Long COVID is a new and complex chronic health condition that typically includes multiple symptoms that cross organ systems and fluctuate over time; a one-size-fits-all approach is, therefore, not likely to be appropriate nor relevant for long COVID treatment. 'Treatable Traits' is a personalized medicine approach, purpose-built to address the complexity and heterogeneity of complex chronic conditions. This comprehensive review aimed to understand how a treatable traits approach could be applied to long COVID, by first identifying the most prevalent long COVID treatable traits and then the available evidence for strategies to target these traits. An umbrella review of 22 systematic reviews identified 34 symptoms and complications common with long COVID, grouped into eight long COVID treatable trait clusters: neurological, chest, psychological, pain, fatigue, sleep impairment, functional impairment and other. A systematic review of randomized control trials identified 18 studies that explored different intervention approaches for long COVID prevention (k = 4) or management (k = 14). While a single study reported metformin as effective for long COVID prevention, the findings need to be replicated and consensus is required around how to define long COVID as a clinical trial endpoint. For long COVID management, current evidence supports exercise training or respiratory muscle training for long COVID treatable traits in the chest and functional limitation clusters. While there are studies exploring interventions targeting other long COVID treatable traits, further high-quality RCTs are needed, particularly targeting treatable traits in the clusters of fatigue, psychological, pain and sleep impairment.

The fluid hospital: On the making of care environments in COVID-19

This paper explores the boundary-making practices enacted by the hospital. Taking a hospital in Sydney, Australia, as our case, we investigate how the hospital holds together as a care environment through the coordinating movements of many materials, spaces, bodies, technologies, and affects. Drawing on interviews with hospital healthcare workers involved in care, research, and management related to COVID-19, we examine the multiplying effects of these movements to trace the ways in which the hospital is (re)made in relation with pandemic assemblages. We accentuate the material affordances of care environments and how care is adapted through the reshaping of the spaces and flows of the hospital. Through this, we highlight how care providers can work with the fluidity of the hospital, including through reorganizing routines and spaces of care, engaging with communication technologies to enact care at many scales, and remaking mundane materials as medical objects in the evolving care environment.

The kynurenine pathway relates to post-acute COVID-19 objective cognitive impairment and PASC

OBJECTIVE

To determine the prevalence and natural history of post-acute COVID-19 objective cognitive impairment and function, and their relationship to demographic, clinical factors, post-acute sequelae of COVID-19 (PASC), and biomarkers.

METHODS

A total of 128 post-acute COVID-19 patients (age = 46 ± 15; 42% women, acute disease severity: not hospitalized: 38.6% mild: 0-1 symptoms, 52% 2+ symptoms; 9.4% hospitalized) completed standard cognition, olfaction, and mental health examinations 2-, 4-, and 12-month post diagnosis. Over the same time frame, WHO-defined PASC was determined. Blood cytokines, peripheral neurobiomarkers, and kynurenine pathway (KP) metabolites were measured. Objective cognitive function was demographically/practice corrected, and impairment prevalence was determined using the evidence-based Global Deficit Score method to detect at least mild cognitive impairment (GDS > 0.5). Linear mixed effect regression models with time effect (month post diagnosis) evaluated the relationships to cognition.

RESULTS

Across the 12-month study period, mild to moderate cognitive impairment ranged from 16% to 26%, and 46.5% were impaired at least once. Impairment associated with poorer work capacity (p < 0.05), and 2-month objectively tested anosmia (p < 0.05). PASC with (p = 0.01) and without disability (p < 0.03) associated with acute COVID-19 severity. KP measures showed prolonged activation (2 to 8 months) (p < 0.0001) linked to IFN-beta in those with PASC. Of the blood analytes, only the KP metabolites (elevated quinolinic acid, 3-hydroxyanthranilic acid, kynurenine, the kynurenine/tryptophan ratio) associated (p < 0.001) with poorer cognitive performance and greater likelihood of impairment. PASC, independent of disability associated with abnormal kynurenine/tryptophan (p < 0.03).

INTERPRETATION

The kynurenine pathway relates to post-acute COVID-19 objective cognitive impairment and PASC, thereby enabling biomarker and therapeutic possibilities.

High titre neutralizing antibodies in response to SARS-CoV-2 infection require RBD-specific CD4 T cells that include proliferative memory cells

Background

Long-term immunity to SARS-CoV-2 infection, including neutralizing antibodies and T cell-mediated immunity, is required in a very large majority of the population in order to reduce ongoing disease burden.

Methods

We have investigated the association between memory CD4 and CD8 T cells and levels of neutralizing antibodies in convalescent COVID-19 subjects.

Findings

Higher titres of convalescent neutralizing antibodies were associated with significantly higher levels of RBD-specific CD4 T cells, including specific memory cells that proliferated vigorously in vitro. Conversely, up to half of convalescent individuals had low neutralizing antibody titres together with a lack of receptor binding domain (RBD)-specific memory CD4 T cells. These low antibody subjects had other, non-RBD, spike-specific CD4 T cells, but with more of an inhibitory Foxp3+ and CTLA-4+ cell phenotype, in contrast to the effector T-bet+, cytotoxic granzymes+ and perforin+ cells seen in RBD-specific memory CD4 T cells from high antibody subjects. Single cell transcriptomics of antigen-specific CD4+ T cells from high antibody subjects similarly revealed heterogenous RBD-specific CD4+ T cells that comprised central memory, transitional memory and Tregs, as well as cytotoxic clusters containing diverse TCR repertoires, in individuals with high antibody levels. However, vaccination of low antibody convalescent individuals led to a slight but significant improvement in RBD-specific memory CD4 T cells and increased neutralizing antibody titres.

Interpretation

Our results suggest that targeting CD4 T cell epitopes proximal to and within the RBD-region should be prioritized in booster vaccines.

Forthcoming complications in recovered COVID-19 patients with COPD and asthma; possible therapeutic opportunities

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been growing swiftly worldwide. Patients with background chronic pulmonary inflammations such as asthma or chronic obstructive pulmonary diseases (COPD) are likely to be infected with this virus. Of note, there is an argument that COVID-19 can remain with serious complications like fibrosis or other pathological changes in the pulmonary tissue of patients with chronic diseases. Along with conventional medications, regenerative medicine, and cell-based therapy could be alternative approaches to compensate for organ loss or restore injured sites using different stem cell types. Owing to unique differentiation capacity and paracrine activity, these cells can accelerate the healing procedure. In this review article, we have tried to scrutinize different reports related to the harmful effects of SARS-CoV-2 on patients with asthma and COPD, as well as the possible therapeutic effects of stem cells in the alleviation of post-COVID-19 complications. Video abstract.

Long Covid brain fog: a neuroinflammation phenomenon?

Neuroinflammation is a process triggered by an attack on the immune system. Activation of microglia in response to an immune system challenge can lead to a significant impact on cognitive processes, such as learning, memory and emotional regulation. Long Covid is an ongoing problem, affecting an estimated 1.3 million people within the UK alone, and one of its more significant, and as yet unexplained, symptoms is brain fog. Here, we discuss the potential role of neuroinflammation in Long Covid cognitive difficulties. Inflammatory cytokines have been found to play a significant role in reductions in LTP and LTD, a reduction in neurogenesis, and in dendritic sprouting. The potential behavioural consequences of such impacts are discussed. It is hoped that this article will allow for greater examination of the effects of inflammatory factors on brain function, most particularly in terms of their role in chronic conditions.

Physical, psychological and cognitive profile of post-COVID conditions in healthcare workers, Quebec, Canada

Background

The prevalence of post-COVID conditions (PCC) and associated physical, psychological and cognitive symptoms was assessed among Quebec healthcare workers (HCWs) with COVID-19.

Methods

This case-control study compared 6061 symptomatic HCWs with PCR-confirmed COVID-19 between July 2020 and May 2021 with a random sample of 4390 symptomatic HCWs who were test-negative controls. The prevalence of physical symptoms lasting ≥4 weeks (PCC4w) or ≥12 weeks (PCC12w) was estimated among hospitalized and non-hospitalized cases. In multivariate models, sociodemographic and clinical characteristics, as well as vaccine history, were evaluated as potential risk factors. Prevalence ratios compared four aspects of self-reported cognitive dysfunction among PCC cases to controls, adjusting for psychological distress and fatigue.

Results

PCC4w and PCC12w prevalences of 46% (2,746/5,943) and 40% (653/1,746), respectively, were observed among non-hospitalized cases and 76% (90/118) and 68% (27/37), respectively, among hospitalized cases. Hospitalization, female sex and age were associated with higher PCC risk.

A substantial proportion of non-hospitalized PCC4w cases often or very often reported cognitive dysfunction, including concentration (33%) or organizing (23%) difficulties, forgetfulness (20%) and loss of necessary items (10%). All four aspects of cognitive dysfunction were associated with PCC4w symptoms, psychological distress and fatigue.

Conclusion

PCC may be a frequent sequela of ambulatory COVID-19 in working-age adults, with important effects on cognition. With so many HCWs infected, the implications for quality healthcare delivery could be profound if cognitive dysfunction and other severe PCC symptoms persist in a professionally-disabling way. Further evaluation of PCC prevalence and prognosis is warranted.

Evaluation of serological assays for SARS-CoV-2 antibody testing from dried blood spots collected from cohorts with prior SARS-CoV-2 infection

Background

Dried blood spot (DBS) specimens are a useful serosurveillance tool particularly in hard-to-reach populations but their application for detecting SARS-CoV-2 infection is poorly characterised.

Objectives

To compare detection of naturally acquired SARS-CoV-2 antibodies in paired DBS and serum specimens using commercially available serological immunoassays.

Study Design

Specimens were collected through St Vincent's Hospital observational post COVID-19 cohort study (ADAPT). Laboratory spotted DBS from venepuncture were initially tested on seven assays, a DBS validation completed on three with clinically collected fingerstick DBSs tested on one.

Results

Sensitivity for Euroimmun nucleocapsid (NCP) IgG ELISA from laboratory spotted DBS (n=145), Euroimmun spike, IgG ELISA from laboratory spotted DBS (n=161), and Binding Site total antibody ELISA from clinically collected fingerstick DBS (n=391) was 100% (95% CI: 95.8-100%), 100% (95% CI: 95.8-100%) and 92.9% (95% CI: 89.5-95.5%), respectively. Specificity was 66.2% (95% CI: 53.6-77.0%), 96% (95% CI: 88.7-99.1%) and 98.8% (95% CI: 93.3-99.9%), respectively. All three assays’ results displayed a strong positive correlation between DBS compared to paired serum.

Conclusions

The Binding Site™ spike total antibody and Euroimmun™ spike IgG ELISAs provided good analytical performance, demonstrating that DBS specimens could facilitate specimen collection in the epidemiological surveillance of SARS-CoV-2 infection. This is highly applicable in populations and settings where venepuncture is problematic (including community based regional/remote settings, nursing homes, prisons, and schools).

COVID-19 associated cognitive impairment: A systematic review

INTRODUCTION

COVID-19 has a wide range of clinical manifestations. Neurological manifestations in COVID-19 patients were demonstrated during the pandemic, including cognitive impairment. This study aimed to determine any relationship between COVID-19 and cognitive complaints, such as dementia, mild cognitive impairment (MCI), or subjective cognitive decline (SCD).

METHODS

We performed a systematic review of MEDLINE via Ebsco, Cochrane EMBASE, SCOPUS, and LILACS electronic databases of observational studies with COVID-19 patients confirmed by serology or PCR who developed new cognitive impairment or deteriorated from previous cognitive impairment after infection. This review protocol was recorded on PROSPERO with registration number CRD 42021241590.

RESULTS

A total of 3.520 articles were retrieved and read. Twenty-two studies were selected for our review. A wide range of cognitive assessment tools (n = 25) was used. The most described affected domains in these studies were executive functions, attention, and episodic memory. Thirteen studies showed a pattern of cognitive impairment in processing speed, inattention, or executive dysfunction assessed through working memory.

CONCLUSION

This review highlights the high frequency of cognitive impairment after COVID-19 infection. However, we were unable to differentiate whether the cognitive impairment found corresponded to mild cognitive impairment or dementia through data from selected studies, and this issue serves as one objective of future studies to be addressed on this topic.

Behavioral problems of pediatric patients recovered from COVID-19 in Wuhan, China

Background

Coronavirus disease 2019 (COVID-19) is profoundly affecting lives around the globe. Previous studies on COVID-19 mainly focused on epidemiological, clinical, and radiological features of patients with confirmed infection. Little attention has been paid to the follow-up of recovered patients. As a vulnerable population to adverse events, the health status of the COVID-19 recovered pediatric patients is of great concern. We aimed to investigate the prevalence of behavioral problems among pediatric patients recovered from the COVID-19 in Wuhan, China.

Methods

A total of 122 children who were suspected or confirmed COVID-19 cases and hospitalized for treatment were enrolled in the study between April 2020 and May 2020 in Wuhan, China. We collected related information about hospitalization and discharge of the children and emotional symptoms of their parents through electronic medical records and questionnaire. The behavioral problems of children were examined by applying the parent-reported the Strengths and Difficulties Questionnaire (SDQ).

Results

The participant children were discharged from hospital after about two months. Among them, 76 (62%) were boys, and the mean age was 6.71 years old. The highest prevalence of behavioral problems among pediatric children with COVID-19 was for prosocial behavior (15%), followed by total difficulties (13%), emotional symptoms (11%), hyperactivity (10%), conduct problems (9%), and peer problems (1%). With regarding to their parents, 26% reported having symptoms of anxiety and 23% as having symptoms of depression. The scores of SDQ were higher in those children whose parents have emotional problems compared to parents without.

Conclusion

Long-term follow up studies on the psychological and behavioral problems of COVID-19 recovered children and their parents are warranted.

Pulmonary function test and computed tomography features during follow-up after SARS, MERS and COVID-19: a systematic review and meta-analysis

Background

The COVID-19 pandemic follows severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronavirus epidemics. Some survivors of COVID-19 infection experience persistent respiratory symptoms, yet their cause and natural history remain unclear. Follow-up after SARS and MERS may provide a model for predicting the long-term pulmonary consequences of COVID-19.

Methods

This systematic review and meta-analysis aims to describe and compare the longitudinal pulmonary function test (PFT) and computed tomography (CT) features of patients recovering from SARS, MERS and COVID-19. Meta-analysis of PFT parameters (DerSimonian and Laird random-effects model) and proportion of CT features (Freeman-Tukey transformation random-effects model) were performed.

Findings

Persistent reduction in the diffusing capacity for carbon monoxide following SARS and COVID-19 infection is seen at 6 months follow-up, and 12 months after MERS. Other PFT parameters recover in this time. 6 months after SARS and COVID-19, ground-glass opacity, linear opacities and reticulation persist in over 30% of patients; honeycombing and traction dilatation are reported less often. Severe/critical COVID-19 infection leads to greater CT and PFT abnormality compared to mild/moderate infection.

Interpretation

Persistent diffusion defects suggestive of parenchymal lung injury occur after SARS, MERS and COVID-19 infection, but improve over time. After COVID-19 infection, CT features are suggestive of persistent parenchymal lung injury, in keeping with a post-COVID-19 interstitial lung syndrome. It is yet to be determined if this is a regressive or progressive disease.

The Pathophysiology of Long COVID throughout the Renin-Angiotensin System

COVID-19 has expanded across the world since its discovery in Wuhan (China) and has had a significant impact on people's lives and health. Long COVID is a term coined by the World Health Organization (WHO) to describe a variety of persistent symptoms after acute SARS-CoV-2 infection. Long COVID has been demonstrated to affect various SARS-CoV-2-infected persons, independently of the acute disease severity. The symptoms of long COVID, like acute COVID-19, consist in the set of damage to various organs and systems such as the respiratory, cardiovascular, neurological, endocrine, urinary, and immune systems. Fatigue, dyspnea, cardiac abnormalities, cognitive and attention impairments, sleep disturbances, post-traumatic stress disorder, muscle pain, concentration problems, and headache were all reported as symptoms of long COVID. At the molecular level, the renin-angiotensin system (RAS) is heavily involved in the pathogenesis of this illness, much as it is in the acute phase of the viral infection. In this review, we summarize the impact of long COVID on several organs and tissues, with a special focus on the significance of the RAS in the disease pathogenesis. Long COVID risk factors and potential therapy approaches are also explored.

Cognitive Dysfunction, Psychiatric Distress, and Functional Decline After COVID-19

BACKGROUND

There is a limited understanding of the cognitive and psychiatric sequelae of COVID-19 during the post-acute phase, particularly among racially and ethnically diverse patients.

OBJECTIVE

We sought to prospectively characterize cognition, mental health symptoms, and functioning approximately four months after an initial diagnosis of COVID-19 in a racially and ethnically diverse group of patients.

METHODS

Approximately four months after COVID-19 diagnosis, patients in the Johns Hopkins Post-Acute COVID-19 Team Pulmonary Clinic underwent a clinical telephone-based assessment of cognition, depression, anxiety, trauma, and function.

RESULTS

Most Johns Hopkins Post-Acute COVID-19 Team patients assessed were women (59%) and members of racial/ethnic minority groups (65%). Of 82 patients, 67% demonstrated ≥1 abnormally low cognitive score. Patients requiring intensive care unit (ICU) stays displayed greater breadth and severity of impairment than those requiring less intensive treatment. Processing speed (35%), verbal fluency (26%-32%), learning (27%), and memory (27%) were most commonly impaired. Among all patients, 35% had moderate symptoms of depression (23%), anxiety (15%), or functional decline (15%); 25% of ICU patients reported trauma-related distress. Neuropsychiatric symptoms and functional decline did not differ by post-ICU versus non-ICU status and were unrelated to global cognitive composite scores.

CONCLUSIONS

At approximately 4 months after acute illness, cognitive dysfunction, emotional distress, and functional decline were common among a diverse clinical sample of COVID-19 survivors varying in acute illness severity. Patients requiring ICU stays demonstrated greater breadth and severity of cognitive impairment than those requiring less intensive treatment. Findings help extend our understanding of the nature, severity, and potential duration of neuropsychiatric morbidity after COVID-19 and point to the need for longitudinal assessment of cognitive and mental health outcomes among COVID-19 survivors of different demographic backgrounds and illness characteristics.

Long-term effects of COVID-19 on mental health: A systematic review

BACKGROUND

Acute effects of COVID-19 can be life-threatening. Alterations in mental health during the active infection have been documented, but the long-term consequences are less clear.

METHOD

A systematic review was undertaken to investigate the effect of COVID-19 infection on long-term mental health outcomes. Three databases [PubMed, Medline (Ovid) and Cochrane library] were searched between 1st October 2019 and 29th August 2021 with additional hand searching to identify all published studies reporting symptoms of generalised anxiety, depression, post-traumatic stress disorder (PTSD), or sleep disturbance in participants at least one month after COVID-19 infection. The prevalence and mean symptom score of each were assessed.

RESULTS

Eight hundred and eighty five studies were found, of which 33 were included in the review involving a total of 6743 participants. The studies' risk of bias were typically fair quality. The median study age of participants was 57.8 years (IQR 49.3-60.7), with 63.0% male (IQR 57.0%-73.0%). Participants typically experienced no or mild symptoms of long-term anxiety (GAD-7, STAI-S, HADS) and depression (PHQ-9, BDI, PHQ-2, HADS). Prevalence varied depending on the measurement tool. Sleep disturbances (primarily insomnia) were most commonly reported as mild. PTSD prevalence was similar to anxiety and depression.

CONCLUSION

The overall effect of the pandemic has been linked with worsening psychiatric symptoms. However, the long-term effect from direct COVID-19 infection has been associated with no or mild symptoms. Studies exhibited the long-term prevalence of anxiety, depression, PTSD, and sleep disturbances to be comparable to general population levels.

Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection

A proportion of patients surviving acute coronavirus disease 2019 (COVID-19) infection develop post-acute COVID syndrome (long COVID (LC)) lasting longer than 12 weeks. Here, we studied individuals with LC compared to age- and gender-matched recovered individuals without LC, unexposed donors and individuals infected with other coronaviruses. Patients with LC had highly activated innate immune cells, lacked naive T and B cells and showed elevated expression of type I IFN (IFN-β) and type III IFN (IFN-λ1) that remained persistently high at 8 months after infection. Using a log-linear classification model, we defined an optimal set of analytes that had the strongest association with LC among the 28 analytes measured. Combinations of the inflammatory mediators IFN-β, PTX3, IFN-γ, IFN-λ2/3 and IL-6 associated with LC with 78.5-81.6% accuracy. This work defines immunological parameters associated with LC and suggests future opportunities for prevention and treatment.

Limited recovery from post-acute sequelae of SARS-CoV-2 at 8 months in a prospective cohort

Global attention is gradually turning to focus on the problem of prolonged illness following acute coronavirus disease 2019 (COVID-19), commonly termed “Long COVID” or post-acute sequelae of SARS-CoV-2 infection (PASC). While an increasing number of reports now recognise this condition, accurate characterisation of its prevalence, clinical features and natural history is complicated by choice of denominator population, lack of case definition and marked self-selection bias. Nevertheless, a picture is emerging of a syndrome characterised predominantly by fatigue, dyspnoea, chest tightness and “brain fog” present in around 10–30% of individuals at 2–3 months post-acute infection and affecting both those with initial severe illness and those in whom acute infection was mild [1–3].

In a longitudinal cohort, a significant proportion of patients had persistent symptoms 8 months after initial #COVID19 infection. There was no significant improvement in symptoms or health-related quality of life between 4- and 8-month assessments.https://bit.ly/2Wtb7IX

Long-term health sequelae and quality of life at least 6 months after infection with SARS-CoV-2: design and rationale of the COVIDOM-study as part of the NAPKON population-based cohort platform (POP)

Purpose

Over the course of COVID-19 pandemic, evidence has accumulated that SARS-CoV-2 infections may affect multiple organs and have serious clinical sequelae, but on-site clinical examinations with non-hospitalized samples are rare. We, therefore, aimed to systematically assess the long-term health status of samples of hospitalized and non-hospitalized SARS-CoV-2 infected individuals from three regions in Germany.

Methods

The present paper describes the COVIDOM-study within the population-based cohort platform (POP) which has been established under the auspices of the NAPKON infrastructure (German National Pandemic Cohort Network) of the national Network University Medicine (NUM). Comprehensive health assessments among SARS-CoV-2 infected individuals are conducted at least 6 months after the acute infection at the study sites Kiel, Würzburg and Berlin. Potential participants were identified and contacted via the local public health authorities, irrespective of the severity of the initial infection. A harmonized examination protocol has been implemented, consisting of detailed assessments of medical history, physical examinations, and the collection of multiple biosamples (e.g., serum, plasma, saliva, urine) for future analyses. In addition, patient-reported perception of the impact of local pandemic-related measures and infection on quality-of-life are obtained.

Results

As of July 2021, in total 6813 individuals infected in 2020 have been invited into the COVIDOM-study. Of these, about 36% wished to participate and 1295 have already been examined at least once.

Conclusion

NAPKON-POP COVIDOM-study complements other Long COVID studies assessing the long-term consequences of an infection with SARS-CoV-2 by providing detailed health data of population-based samples, including individuals with various degrees of disease severity.

Trial registration

Registered at the German registry for clinical studies (DRKS00023742).

Long COVID and Post-infective Fatigue Syndrome: A Review

Fatigue is a dominant feature of both acute and convalescent coronavirus disease 2019 (COVID-19) (sometimes termed "long-COVID"), with up to 46% of patients reporting fatigue that lasts from weeks to months. The investigators of the international Collaborative on Fatigue Following Infection (COFFI) conducted a systematic review of post-COVID fatigue and a narrative review on fatigue after other infections, and made recommendations for clinical and research approaches to assessing fatigue after COVID-19. In the majority of COVID-19 cohort studies, persistent fatigue was reported by a significant minority of patients, ranging from 13% to 33% at 16-20 weeks post-symptom onset. Data from the prospective cohort studies in COFFI and others indicate that fatigue is also a prevalent outcome from many acute systemic infections, notably infectious mononucleosis, with a case rate for clinically significant Post-infective fatigue after exclusion of recognized medical and psychiatric causes, ranging from 10%-35% at 6 months. To better characterize post-COVID fatigue, the COFFI investigators recommend the following: application of validated screening questionnaires for case detection; standardized interviews encompassing fatigue, mood, and other symptoms; and investigative approaches to identify end-organ damage and mental health conditions.

Psychiatric and neuropsychiatric sequelae of COVID-19 - A systematic review

It has become evident that coronavirus disease 2019 (COVID-19) has a multi-organ pathology that includes the brain and nervous system. Several studies have also reported acute psychiatric symptoms in COVID-19 patients. An increasing number of studies are suggesting that psychiatric deficits may persist after recovery from the primary infection. In the current systematic review, we provide an overview of the available evidence and supply information on potential risk factors and underlying biological mechanisms behind such psychiatric sequelae. We performed a systematic search for psychiatric sequelae in COVID-19 patients using the databases PubMed and Embase. Included primary studies all contained information on the follow-up period and provided quantitative measures of mental health. The search was performed on June 4th 2021. 1725 unique studies were identified. Of these, 66 met the inclusion criteria and were included. Time to follow-up ranged from immediately after hospital discharge up to 7 months after discharge, and the number of participants spanned 3 to 266,586 participants. Forty studies reported anxiety and/or depression, 20 studies reported symptoms- or diagnoses of post-traumatic stress disorder (PTSD), 27 studies reported cognitive deficits, 32 articles found fatigue at follow-up, and sleep disturbances were found in 23 studies. Highlighted risk factors were disease severity, duration of symptoms, and female sex. One study showed brain abnormalities correlating with cognitive deficits, and several studies reported inflammatory markers to correlate with symptoms. Overall, the results from this review suggest that survivors of COVID-19 are at risk of psychiatric sequelae but that symptoms generally improve over time.

Prediction of COVID-19 deterioration in high-risk patients at diagnosis: an early warning score for advanced COVID-19 developed by machine learning

PURPOSE

While more advanced COVID-19 necessitates medical interventions and hospitalization, patients with mild COVID-19 do not require this. Identifying patients at risk of progressing to advanced COVID-19 might guide treatment decisions, particularly for better prioritizing patients in need for hospitalization.

METHODS

We developed a machine learning-based predictor for deriving a clinical score identifying patients with asymptomatic/mild COVID-19 at risk of progressing to advanced COVID-19. Clinical data from SARS-CoV-2 positive patients from the multicenter Lean European Open Survey on SARS-CoV-2 Infected Patients (LEOSS) were used for discovery (2020-03-16 to 2020-07-14) and validation (data from 2020-07-15 to 2021-02-16).

RESULTS

The LEOSS dataset contains 473 baseline patient parameters measured at the first patient contact. After training the predictor model on a training dataset comprising 1233 patients, 20 of the 473 parameters were selected for the predictor model. From the predictor model, we delineated a composite predictive score (SACOV-19, Score for the prediction of an Advanced stage of COVID-19) with eleven variables. In the validation cohort (n = 2264 patients), we observed good prediction performance with an area under the curve (AUC) of 0.73 ± 0.01. Besides temperature, age, body mass index and smoking habit, variables indicating pulmonary involvement (respiration rate, oxygen saturation, dyspnea), inflammation (CRP, LDH, lymphocyte counts), and acute kidney injury at diagnosis were identified. For better interpretability, the predictor was translated into a web interface.

CONCLUSION

We present a machine learning-based predictor model and a clinical score for identifying patients at risk of developing advanced COVID-19.

SARS-CoV-2 neutralizing antibodies: Longevity, breadth, and evasion by emerging viral variants

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antibody neutralization response and its evasion by emerging viral variants and variant of concern (VOC) are unknown, but critical to understand reinfection risk and breakthrough infection following vaccination. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus-cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 reverse transcription polymerase chain reaction (RT-PCR)-confirmed Coronavirus Disease 2019 (COVID-19) individuals with detailed demographics and followed up to 7 months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization, was associated with COVID-19 severity. A subgroup of "high responders" maintained high neutralizing responses over time, representing ideal convalescent plasma donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants and VOC. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal responders and vaccine monitoring and design.

Characteristics and predictors of acute and chronic post-COVID syndrome: A systematic review and meta-analysis

BACKGROUND

A significant proportion of individuals experience lingering and debilitating symptoms following acute COVID-19 infection. The National Institute for Health and Care Excellence (NICE) have coined the persistent cluster of symptoms as post-COVID syndrome. This has been further sub-categorised into acute post-COVID syndrome for symptoms persisting three weeks beyond initial infection and chronic post-COVID syndrome for symptoms persisting beyond twelve weeks. The aim of this review was to detail the prevalence of clinical features and identify potential predictors for acute and chronic post-COVID syndrome.

METHODS

A systematic literature search, with no language restrictions, was performed to identify studies detailing characteristics and outcomes related to survivorship of post-COVID syndrome. The last search was performed on 6 March 2021 and all pre-dating published articles included. A means of proportion meta-analysis was performed to quantify characteristics of acute and chronic post-COVID syndrome. Study quality was assessed with a specific risk of bias tool. PROSPERO Registration: CRD42020222855.

FINDINGS

A total of 43 studies met the eligibility criteria; of which, 38 allowed for meta-analysis. Fatigue and dyspnoea were the most prevalent symptoms in acute post-COVID (0·37 and 0·35) and fatigue and sleep disturbance in chronic post-COVID syndrome (0·48 and 0·44), respectively. The available evidence is generally of poor quality, with considerable risk of bias, and are of observational design.

INTERPRETATION

In conclusion, this review highlights that flaws in data capture and interpretation, noted in the uncertainty within our meta-analysis, affect the applicability of current knowledge. Policy makers and researchers must focus on understanding the impact of this condition on individuals and society with appropriate funding initiatives and global collaborative research.

Post-Acute COVID-19 Syndrome and the cardiovascular system: What is known?

Post-Acute COVID-19 Syndrome (PACS) is defined by persistent symptoms >3-4 weeks after onset of COVID-19. The mechanism of these persistent symptoms is distinct from acute COVID-19 although not completely understood despite the high incidence of PACS. Cardiovascular symptoms such as chest pain and palpitations commonly occur in PACS, but the underlying cause of symptoms is infrequently known. While autopsy studies have shown that the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rarely causes direct myocardial injury, several syndromes such as myocarditis, pericarditis, and Postural Orthostatic Tachycardia Syndrome have been implicated in PACS. Additionally, patients hospitalized with acute COVID-19 who display biomarker evidence of myocardial injury may have underlying coronary artery disease revealed by the physiological stress of SARS-CoV-2 infection and may benefit from medical optimization. We review what is known about PACS and the cardiovascular system and propose a framework for evaluation and management of related symptoms.

COVID-19 and post-infectious myalgic encephalomyelitis/chronic fatigue syndrome: a narrative review

Coronavirus disease 2019 (COVID-19) is a viral infection which can cause a variety of respiratory, gastrointestinal, and vascular symptoms. The acute illness phase generally lasts no more than 2-3 weeks. However, there is increasing evidence that a proportion of COVID-19 patients experience a prolonged convalescence and continue to have symptoms lasting several months after the initial infection. A variety of chronic symptoms have been reported including fatigue, dyspnea, myalgia, exercise intolerance, sleep disturbances, difficulty concentrating, anxiety, fever, headache, malaise, and vertigo. These symptoms are similar to those seen in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a chronic multi-system illness characterized by profound fatigue, sleep disturbances, neurocognitive changes, orthostatic intolerance, and post-exertional malaise. ME/CFS symptoms are exacerbated by exercise or stress and occur in the absence of any significant clinical or laboratory findings. The pathology of ME/CFS is not known: it is thought to be multifactorial, resulting from the dysregulation of multiple systems in response to a particular trigger. Although not exclusively considered a post-infectious entity, ME/CFS has been associated with several infectious agents including Epstein-Barr Virus, Q fever, influenza, and other coronaviruses. There are important similarities between post-acute COVID-19 symptoms and ME/CFS. However, there is currently insufficient evidence to establish COVID-19 as an infectious trigger for ME/CFS. Further research is required to determine the natural history of this condition, as well as to define risk factors, prevalence, and possible interventional strategies.