Clinical, virological and imaging profile in patients with prolonged forms of COVID-19: A cross-sectional study

Assessing the association between antibody status and symptoms of long COVID: A multisite study

The association between SARS-CoV-2 humoral immunity and post-acute sequelae of COVID-19 (long COVID) remains uncertain. The objective of this population-based cohort study was to assess the association between SARS-CoV-2 seropositivity and symptoms consistent with long COVID. English and Spanish-speaking members ≥ 18 years old with SARS-CoV-2 serologic testing conducted prior to August 2021 were recruited from Kaiser Permanente Southern California and Kaiser Permanente Colorado. Between November 2021 and April 2022, participants completed a survey assessing symptoms, physical health, mental health, and cognitive function consistent with long COVID. Survey results were linked to SARS-CoV-2 antibody (Ab) and viral (RNA) lab results in electronic health records. Weighted descriptive analyses were generated for five mutually exclusive patient groups: (1) +Ab/+RNA; (2) +Ab/- or missing RNA; (3) -Ab/+RNA; (4a) -Ab/-RNA reporting no prior infection; and (4b) -Ab/-RNA reporting prior infection. The proportions reporting symptoms between the +Ab/+RNA and -Ab/+RNA groups were compared, adjusted for covariates. Among 3,946 participants, the mean age was 52.1 years old (SD 15.6), 68.3% were female, 28.4% were Hispanic, and the serologic testing occurred a median of 15 months prior (IQR = 12-18). Three quarters (74.5%) reported having had COVID-19. Among people with laboratory-confirmed COVID-19, there was no association between antibody positivity (+Ab/+RNA vs. -Ab/+RNA) and any symptoms, physical health, mental health, or cognitive function. As expected, physical health, cognitive function, and fatigue were worse, and palpitations and headaches limiting the ability to work were more prevalent among people with laboratory-confirmed prior infection and positive serology (+Ab/+RNA) compared to those without reported or confirmed prior infection and negative serology (-Ab/-RNA/no reported COVID-19). Among people with laboratory-confirmed COVID-19, SARS-CoV-2 serology from practice settings were not associated with long COVID symptoms and health status suggesting limited utility of serology testing for long COVID.

Current landscape of long COVID clinical trials

Long COVID was reported as a multi-systemic condition after the infection of SARS-CoV-2, and more than 65 million people are suffering from this disease. It has been noted that around 10% of severe SARS-CoV-2 infected individuals are suffering from the enduring effects of long COVID. The symptoms of long COVID have also been noted in several mild or asymptomatic SARS-CoV-2 infected individuals. While limited reports on clinical trials investigating new therapeutics for long COVID exist, there is an abundance of scattered information available regarding these trials. This review explores the extensive literature search, and complete clinical trial database search to map the current status of long COVID clinical trials worldwide. The study listed about 110 long COVID clinical trials. In addition to conducting extensive long COVID clinical trials, we have comprehensively presented an overview of the condition, its symptoms, notable manifestations, associated clinical trials, the unique challenges it poses, and our recommendations for addressing long COVID.

Patients with Long COVID continue to experience significant symptoms at 12 months and factors associated with improvement: A prospective cohort study in France (PERSICOR)

OBJECTIVES

This study examines long COVID symptoms course over 12 months, their impact on daily life, and associated factors for symptom relief.

METHODS

A prospective cohort study included 231 participants with long COVID at 12-month follow-up. Data on characteristics, symptom course, and remission were collected using a questionnaire and a remission scale. Poisson regression models were used to estimate the prevalence rate ratio (PRR) and 95% confidence intervals (CIs) for factors associated with symptom improvement.

RESULTS

Of the 231 participants, 63.2% developed SARS-CoV-2 antibodies before COVID-19 vaccination. At 12 months, only 8.7% (95% CI: 5.4-13.1%) reported complete remission, while 28.6% noted significant improvement. Most symptoms remained prevalent: asthenia (83.1%), neurocognitive/neurological (93.9%), cardiothoracic (77.9%), Musculoskeletal (78.8%). During long COVID, 62.2% stopped working, and only 32.5% resumed full-time professional activities. Presence of SARS-CoV-2 antibodies before vaccination increased the probability of improvement (aPRR: 1.60, P = 0.028), while ageusia at initial long COVID phase decreased the probability (aPRR: 0.38, P = 0.007).

CONCLUSIONS

Long-COVID symptoms persisted in the majority of participants after 12 months, with significant impacts on daily life and work. SARS-CoV-2 antibodies were associated with better prognosis, while persistent ageusia indicated a lower probability of improvement. These findings highlight the need for ongoing support and care for individuals with long COVID.

New approaches for understanding the potential role of microbes in Alzheimer's disease

Alzheimer's disease (AD) involves a complex pathological process that evolves over years, and its etiology is understood as a classic example of gene-environment interaction. The notion that exposure to microbial organisms may play some role in AD pathology has been proposed and debated for decades. New evidence from model organisms and -omic studies, as well as epidemiological data from the recent COVID-19 pandemic and widespread use of vaccines, offers new insights into the "germ hypothesis" of AD. To review new evidence and identify key research questions, the Duke/University of North Carolina (Duke/UNC) Alzheimer's Disease Research Center hosted a virtual symposium and workshop: "New Approaches for Understanding the Potential Role of Microbes in Alzheimer's disease." Discussion centered around the antimicrobial protection hypothesis of amyloid accumulation, and other mechanisms by which microbes could influence AD pathology including immune cell activation, changes in blood-brain barrier, or direct neurotoxicity. This summary of proceedings reviews the content presented in the symposium and provides a summary of major topics and key questions discussed in the workshop.

Intrinsic factors behind long COVID: III. Persistence of SARS-CoV-2 and its components

Considerable research has been done in investigating SARS-CoV-2 infection, its characteristics, and host immune response. However, debate is still ongoing over the emergence of post-acute sequelae of SARS-CoV-2 infection (PASC). A multitude of long-lasting symptoms have been reported several weeks after the primary acute SARS-CoV-2 infection that resemble several other viral infections. Thousands of research articles have described various post-COVID-19 conditions. Yet, the evidence around these ongoing health problems, the reasons behind them, and their molecular underpinnings are scarce. These persistent symptoms are also known as long COVID-19. The persistence of SARS-CoV-2 and/or its components in host tissues can lead to long COVID. For example, the presence of viral nucleocapsid protein and RNA was detected in the skin, appendix, and breast tissues of some long COVID patients. The persistence of viral RNA was reported in multiple anatomic sites, including non-respiratory tissues such as the adrenal gland, ocular tissue, small intestine, lymph nodes, myocardium, and sciatic nerve. Distinctive viral spike sequence variants were also found in non-respiratory tissues. Interestingly, prolonged detection of viral subgenomic RNA was observed across all tissues, sometimes in multiple tissues of the same patient, which likely reflects recent but defective viral replication. Moreover, the persistence of SARS-CoV-2 RNA was noticed throughout the brain at autopsy, as late as 230 days following symptom onset among unvaccinated patients who died of severe infection. Here, we review the persistence of SARS-CoV-2 and its components as an intrinsic factor behind long COVID. We also highlight the immunological consequences of this viral persistence.

Evaluation of long-COVID symptoms in women infected with SARS-CoV-2 during pregnancy

OBJECTIVE

To evaluate the symptoms of Long COVID (LC), frequency of symptoms, and possible risk factors in women diagnosed with coronavirus disease 2019 (COVID-19) during pregnancy.

METHODS

We conducted a single-center, cross-sectional, retrospective study in 99 pregnant women who were polymerase chain reaction-positive (PCR+) for COVID-19 between March 1, 2020 and April 30, 2022. The control group consisted of 99 women who gave birth between these dates and did not have COVID-19. We evaluated the clinical manifestations, symptom prevalence, and symptom characteristics of acute COVID-19 and the LC in the PCR+ group as well as questioned the control group for LC symptoms.

RESULTS

Of the women in the PCR+ group, 74 (74.7%) had at least one LC symptom, and the most common symptoms were fatigue (54; 72.9%), myalgia/arthralgia (49; 66.2%), and anosmia/ageusia (31; 41.9%). The rate of LC symptoms in the control group was 14 (14.1%). The prevalence of LC symptoms was higher in severely/critically symptomatic patients (23; 100%) in the acute period of disease than in asymptomatic/mildly symptomatic (51; 67.1%) (P = 0.005). Hospitalization during acute infection (adjusted odds ratio [aOR] = 13.30), having one or more symptoms (aOR = 4.75), and having symptoms such as cough (aOR = 6.27) and myalgia/arthralgia (aOR = 12.93) increased the likelihood of LC.

CONCLUSION

Many women experienced LC after suffering acute COVID-19 in pregnancy, but LC prevalence was similar to the general population. LC correlates with severity, type, and number of symptoms of acute COVID-19.

Incidence of long-term post-acute sequelae of SARS-CoV-2 infection related to pain and other symptoms: A systematic review and meta-analysis

BACKGROUND

Persistent symptoms are reported in patients who survive the initial stage of COVID-19, often referred to as "long COVID" or "post-acute sequelae of SARS-CoV-2 infection" (PASC); however, evidence on their incidence is still lacking, and symptoms relevant to pain are yet to be assessed.

METHODS

A literature search was performed using the electronic databases PubMed, EMBASE, Scopus, and CHINAL and preprint servers MedRχiv and BioRχiv through January 15, 2021. The primary outcome was pain-related symptoms such as headache or myalgia. Secondary outcomes were symptoms relevant to pain (depression or muscle weakness) and symptoms frequently reported (anosmia and dyspnea). Incidence rates of symptoms were pooled using inverse variance methods with a DerSimonian-Laird random-effects model. The source of heterogeneity was explored using meta-regression, with follow-up period, age and sex as covariates.

RESULTS

In total, 38 studies including 19,460 patients were eligible. Eight pain-related symptoms and 26 other symptoms were identified. The highest pooled incidence among pain-related symptoms was chest pain (17%, 95% confidence interval [CI], 11%-24%), followed by headache (16%, 95% CI, 9%-27%), arthralgia (13%, 95% CI, 7%-24%), neuralgia (12%, 95% CI, 3%-38%) and abdominal pain (11%, 95% CI, 7%-16%). The highest pooled incidence among other symptoms was fatigue (44%, 95% CI, 32%-57%), followed by insomnia (27%, 95% CI, 10%-55%), dyspnea (26%, 95% CI, 17%-38%), weakness (25%, 95% CI, 8%-56%) and anosmia (19%, 95% CI, 13%-27%). Substantial heterogeneity was identified (I2, 50-100%). Meta-regression analyses partially accounted for the source of heterogeneity, and yet, 53% of the symptoms remained unexplained.

CONCLUSIONS

The current meta-analysis may provide a complete picture of incidence in PASC. It remains unclear, however, whether post-COVID symptoms progress or regress over time or to what extent PASC are associated with age or sex.

Pathophysiology, diagnosis, and management of neuroinflammation in covid-19

Although neurological complications of SARS-CoV-2 infection are relatively rare, their potential long term morbidity and mortality have a significant impact, given the large numbers of infected patients. Covid-19 is now in the differential diagnosis of a number of common neurological syndromes including encephalopathy, encephalitis, acute demyelinating encephalomyelitis, stroke, and Guillain-Barré syndrome. Physicians should be aware of the pathophysiology underlying these presentations to diagnose and treat patients rapidly and appropriately. Although good evidence has been found for neurovirulence, the neuroinvasive and neurotropic potential of SARS-CoV-2 is limited. The pathophysiology of most complications is immune mediated and vascular, or both. A significant proportion of patients have developed long covid, which can include neuropsychiatric presentations. The mechanisms of long covid remain unclear. The longer term consequences of infection with covid-19 on the brain, particularly in terms of neurodegeneration, will only become apparent with time and long term follow-up.

Divergent adaptive immune responses define two types of long COVID

Background

The role of adaptive immune responses in long COVID remains poorly understood, with contrasting hypotheses suggesting either an insufficient antiviral response or an excessive immune response associated with inflammatory damage. To address this issue, we set to characterize humoral and CD4+ T cell responses in long COVID patients prior to SARS-CoV-2 vaccination.

Methods

Long COVID patients who were seropositive (LC+, n=28) or seronegative (LC-, n=23) by spike ELISA assay were recruited based on (i) an initial SARS-CoV-2 infection documented by PCR or the conjunction of three major signs of COVID-19 and (ii) the persistence or resurgence of at least 3 symptoms for over 3 months. They were compared to COVID patients with resolved symptoms (RE, n=29) and uninfected control individuals (HD, n=29).

Results

The spectrum of persistent symptoms proved similar in both long COVID groups, with a trend for a higher number of symptoms in the seronegative group (median=6 vs 4.5; P=0.01). The use a highly sensitive S-flow assay enabled the detection of low levels of SARS-CoV-2 spike-specific IgG in 22.7% of ELISA-seronegative long COVID (LC-) patients. In contrast, spike-specific IgG levels were uniformly high in the LC+ and RE groups. Multiplexed antibody analyses to 30 different viral antigens showed that LC- patients had defective antibody responses to all SARS-CoV-2 proteins tested but had in most cases preserved responses to other viruses. A sensitive primary T cell line assay revealed low but detectable SARS-CoV-2-specific CD4 responses in 39.1% of LC- patients, while response frequencies were high in the LC+ and RE groups. Correlation analyses showed overall strong associations between humoral and cellular responses, with exceptions in the LC- group.

Conclusions

These findings provide evidence for two major types of antiviral immune responses in long COVID. Seropositive patients showed coordinated cellular and humoral responses at least as high as those of recovered patients. In contrast, ELISA-seronegative long COVID patients showed overall low antiviral responses, with detectable specific CD4+ T cells and/or antibodies in close to half of patients (52.2%). These divergent findings in patients sharing a comparable spectrum of persistent symptoms raise the possibility of multiple etiologies in long COVID.

One-Step Quantification of anti-Covid-19 Antibodies via Dual Affinity Ratiometric Quenching Assays

The global pandemic caused by acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people and paralyzed healthcare systems worldwide. Developing rapid and accurate tests to detect and quantify anti-SARS-CoV-2 antibodies in complex fluids is critical to (i) track and address the spread of SARS-CoV-2 variants with different virulence and (ii) support the industrial manufacturing and clinical administration of anti-SARS-CoV-2 therapeutic antibodies. Conventional immunoassays, such as lateral flow, ELISA, and surface plasmon resonance (SPR), are either qualitative or, when quantitative, are laborious and expensive and suffer from high variability. Responding to these challenges, this study evaluates the performance of the Dual-Affinity Ratiometric Quenching (DARQ) assay for the quantification of anti-SARS-CoV-2 antibodies in bioprocess harvests and intermediate fractions (i.e., a Chinese hamster ovary (CHO) cell culture supernatant and a purified eluate) and human fluids (i.e., saliva and plasma). Monoclonal antibodies targeting the SARS-CoV-2 nucleocapsid as well as the spike protein of the delta and omicron variants are adopted as model analytes. Additionally, conjugate pads loaded with dried protein were studied as an at-line quantification method that can be used in clinical or manufacturing laboratories. Our results indicate that the DARQ assay is a highly reproducible (coefficient of variation ∼0.5-3%) and rapid (<10 min) test, whose sensitivity (∼0.23-2.5 ng/mL), limit of detection (23-250 ng/mL), and dynamic range (70-1300 ng/mL) are independent of sample complexity, thus representing a valuable tool for monitoring anti-SARS-CoV-2 antibodies.

Association between SARS-CoV-2 anti-spike antibody titers and the development of post-COVID conditions: A retrospective observational study

The symptoms that persist after an acute coronavirus disease 2019 (COVID-19) are referred to as post- COVID conditions. Although the cause of post-COVID conditions remains unclear, the host immune response to SARS-CoV-2 may be involved. Hence, we aimed to investigate the effect of serum antibody titers against SARS-CoV-2 on the development of post-COVID conditions. We conducted a retrospective observational study of COVID-19-recovered individuals who attended the clinic at the National Center for Global Health and Medicine between January 2020 and April 2021. Serum SARS-CoV-2 anti-spike antibody titers were measured and a questionnaire survey was used to collect information on the presence of post-COVID conditions and demographic characteristics of the participants. Participants were then divided into two groups: high peak antibody titer group [≥ 0.759 OD450 value], and low peak antibody titer group [< 0.759 OD450 value] and compared their frequency of post-COVID conditions. Of 526 individuals attending the clinic, 457 (86.9%) responded to the questionnaire. We analyzed the data of 227 (49.7%) participants with measurements of serum antibody titers during the peak period. The incidence of depressed mood was significantly higher in the group with higher antibody titers (odds ratio: 2.34, 95% CI: 1.17-4.67, p = 0.016). There was no significant difference in the frequency of the remaining symptoms between the two groups. Among post-COVID conditions, the depressed mood was more frequent in the group with high serum antibody titers which suggests a difference in pathogenesis between depressive mood and other post-COVID conditions that requires further investigation.

Physical and cognitive impairments in people suffering from long COVID: protocol for a longitudinal population-based cohort study

INTRODUCTION

Approximately 33% of people who contracted COVID-19 still experience symptoms 12 weeks after infection onset. This persistence of symptoms is now considered a syndrome itself called 'long COVID'. Evidence regarding long COVID and its cognitive and physical impacts is growing, but the literature is currently lacking objectively measured data to guide towards adapted healthcare trajectories. The objectives are to describe the physical and cognitive impairments experienced by individuals living with long COVID using self-reported and clinical objective measures, and to compare the evolution over time of the physical and cognitive state between adults living with long COVID (at least one physical or cognitive COVID-19 symptom for more than 12 weeks following infection; long COVID group), people who developed COVID-19 but did not experience persistent symptoms (short COVID group) and people who did not develop COVID-19 (control group).

METHODS AND ANALYSIS

In this longitudinal cohort study, 120 participants will be recruited in each group. Variables will be collected through three evaluation sessions over 6 months (baseline, 3 months, 6 months). Variables include self-administered questionnaires on health-related quality of life, comorbidity, sleep, pain, anxiety, depressive symptoms, fatigue and cognitive function, as well as objective measures of cognitive (attention, memory, executive functioning) and physical (grip strength, balance, gait speed, gait endurance, VO2, frailty) functions. Activity, heart rate and sleep will be monitored with a fitness tracker watch for 7 days following evaluation sessions. Maximum-likelihood analyses of variance (ANOVAs) will be used to compare data at baseline between groups. Repeated measures ANOVAs will be used to compare the longitudinal performance variations across groups of the self-reported and clinical variables.

ETHICS AND DISSEMINATION

Ethics committees of the CIUSSS de la Capitale-Nationale and CIUSSS de l'Est-de-l'Île-de-Montréal approved the project. Results will be disseminated through clinical and community platforms as well as through peer-reviewed manuscripts and international conferences.

TRIAL REGISTRATION NUMBER

NCT05216536.

Sleep Disorders in Post-COVID Syndrome: A Psychiatric or Neurological Problem?

The coronavirus pandemic that began in 2019 continues. COVID-19 adversely affects human health not only in the acute, but also in the long-term period of the disease: in a large percentage of cases, health is not fully restored after long periods, requires medical intervention, and is often difficult to correct. Researchers noted during the first wave of the pandemic in 2020 that about 10–20% of patients did not fully recover by three weeks from disease onset and the possible duration of the recovery period remains insufficiently clear, as do the reasons for differences in course during this period. Prolonged recovery after viral infection is not a feature exclusive to COVID-19, which does not facilitate the management of patients with post-COVID syndrome (PCS). The mental health impact of COVID-19 is significant, with at least 30% of recovered patients likely to have symptoms of anxiety and/or depression after the acute phase has passed. Since the onset of COVID-19, there has been an increase in sleep disorders by 42%, with every third COVID-19 survivor reporting sleep complaints. In PCS, this condition is referred to as coronasomnia. The success of therapy for this condition depends on identifying and correcting patients’ mental disorders, as anxiety and depression are often accompanied by sleep disorders this results in a bidirectional interaction between mental disorders and sleep quality. This article presents data on the anti-anxiety drugs Noofen and Adaptol, which help to correct the manifestations of PCS with sleep disorders.

The role of immune activation and antigen persistence in acute and long COVID

In late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered the global coronavirus disease 2019 (COVID-19) pandemic. Although most infections cause a self-limited syndrome comparable to other upper respiratory viral pathogens, a portion of individuals develop severe illness leading to substantial morbidity and mortality. Furthermore, an estimated 10%-20% of SARS-CoV-2 infections are followed by post-acute sequelae of COVID-19 (PASC), or long COVID. Long COVID is associated with a wide variety of clinical manifestations including cardiopulmonary complications, persistent fatigue, and neurocognitive dysfunction. Severe acute COVID-19 is associated with hyperactivation and increased inflammation, which may be an underlying cause of long COVID in a subset of individuals. However, the immunologic mechanisms driving long COVID development are still under investigation. Early in the pandemic, our group and others observed immune dysregulation persisted into convalescence after acute COVID-19. We subsequently observed persistent immune dysregulation in a cohort of individuals experiencing long COVID. We demonstrated increased SARS-CoV-2-specific CD4⁺ and CD8⁺ T-cell responses and antibody affinity in patients experiencing long COVID symptoms. These data suggest a portion of long COVID symptoms may be due to chronic immune activation and the presence of persistent SARS-CoV-2 antigen. This review summarizes the COVID-19 literature to date detailing acute COVID-19 and convalescence and how these observations relate to the development of long COVID. In addition, we discuss recent findings in support of persistent antigen and the evidence that this phenomenon contributes to local and systemic inflammation and the heterogeneous nature of clinical manifestations seen in long COVID.

Physical function and fatigue recovery at 6 months after hospitalization for COVID-19

INTRODUCTION

There are an increasing number of individuals with long-term symptoms of coronavirus-19 disease (COVID-19); however, the prognosis for recovery of physical function and fatigue after COVID-19 is uncertain.

OBJECTIVE

To report the changes in functional recovery between 1 and 6 months after hospitalization of adults hospitalized for COVID-19 and explore the baseline factors associated with physical function recovery.

DESIGN

A prospective cohort study.

SETTING

Tertiary care hospital.

PARTICIPANTS

U.S. adult COVID-19 survivors.

INTERVENTION

N/A.

MAIN OUTCOME MEASURES

Telephone interviews assessed three outcome domains: basic and instrumental activities of daily living (ADLs) performance, fatigue, and general physical function (Health Assessment Questionnaire [HAQ]).

RESULTS

The age of participants (n = 92) ranged from 22 to 95 years (54.3 ± 17.2). Across outcome domains, a majority (63%-67%) of participants developed new ADL impairment, fatigue, or worsening HAQ severity by 1 month. Of those, 50%-79% partially or fully recovered by 6 months, but 21%-50% did not recover at least partially. Fifteen to 30% developed new impairment between 1 and 6 months. For those without any improvement in ADL impairments at 6 months, lower socioeconomic status was significantly more common (p = .01) and age ≥ 65 (p = .06), trending toward being more common.

CONCLUSION

In this cohort, a substantial proportion of the participants who developed new ADL impairment, worsening fatigue, or HAQ severity after hospitalization for COVID-19 did not recover at least partially by 6 months after discharge. Evaluating functional status 1 month after discharge may be important in understanding functional prognosis and recovery after hospitalization for COVID-19.

Enhancing COVID Rehabilitation with Technology (ECORT): protocol for an open-label, single-site randomized controlled trial evaluating the effectiveness of electronic case management for individuals with persistent COVID-19 symptoms

BACKGROUND

As of May 2022, Ontario has seen more than 1.3 million cases of COVID-19. While the majority of individuals will recover from infection within 4 weeks, a significant subset experience persistent and often debilitating symptoms, known as "post-COVID syndrome" or "Long COVID." Those with Long COVID experience a wide array of symptoms, with variable severity, including fatigue, cognitive impairment, and shortness of breath. Further, the prevalence and duration of Long COVID is not clear, nor is there evidence on the best course of rehabilitation for individuals to return to their desired level of function. Previous work with chronic conditions has suggested that the addition of electronic case management (ECM) may help to improve outcomes. These platforms provide enhanced connection with care providers, detailed symptom tracking and goal setting, and access to relevant resources. In this study, our primary aim is to determine if the addition of ECM with health coaching improves Long COVID outcomes at 3 months compared to health coaching alone.

METHODS

The trial is an open-label, single-site, randomized controlled trial of ECM with health coaching (ECM+) compared to health coaching alone (HC). Both groups will continue to receive usual care. Participants will be randomized equally to receive health coaching (± ECM) for a period of 8 weeks and a 12-week follow-up. Our primary outcome is the WHO Disability Assessment Scale (WHODAS), 36-item self-report total score. Participants will also complete measures of cognition, fatigue, breathlessness, and mental health. Participants and care providers will be asked to complete a brief qualitative interview at the end of the study to evaluate acceptability and implementation of the intervention.

DISCUSSION

There is currently little evidence about the optimal treatment of Long COVID patients or the use of digital health platforms in this population. The results of this trial could result in rapid, scalable, and personalized care for people with Long COVID which will decrease morbidity after an acute infection. Results from this study will also inform decision making in Long COVID and treatment guidelines at provincial and national levels.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05019963. Registered on 25 August 2021.

After the virus has cleared-Can preclinical models be employed for Long COVID research?

Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) can cause the life-threatening acute respiratory disease called COVID-19 (Coronavirus Disease 2019) as well as debilitating multiorgan dysfunction that persists after the initial viral phase has resolved. Long COVID or Post-Acute Sequelae of COVID-19 (PASC) is manifested by a variety of symptoms, including fatigue, dyspnea, arthralgia, myalgia, heart palpitations, and memory issues sometimes affecting between 30% and 75% of recovering COVID-19 patients. However, little is known about the mechanisms causing Long COVID and there are no widely accepted treatments or therapeutics. After introducing the clinical aspects of acute COVID-19 and Long COVID in humans, we summarize the work in animals (mice, Syrian hamsters, ferrets, and nonhuman primates (NHPs)) to model human COVID-19. The virology, pathology, immune responses, and multiorgan involvement are explored. Additionally, any studies investigating time points longer than 14 days post infection (pi) are highlighted for insight into possible long-term disease characteristics. Finally, we discuss how the models can be leveraged for treatment evaluation, including pharmacological agents that are currently in human clinical trials for treating Long COVID. The establishment of a recognized Long COVID preclinical model representing the human condition would allow the identification of mechanisms causing disease as well as serve as a vehicle for evaluating potential therapeutics.

The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications

Ischaemia–reperfusion (I–R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I–R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.

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OBJECTIVES

To assess the diagnosis of somatic symptom disorder (SSD) in patients with unexplained neurological symptoms occurring after SARS-CoV-2 infection, also referred to as long COVID.

DESIGN

Single-centre observational study.

PARTICIPANTS

Adult patients experiencing unexplained long-lasting neurological symptoms after mild COVID. Of the 58 consecutive patients referred in our centre, 50 were included.

INTERVENTION

Patients were contacted for a standardised psychometric evaluation by phone, followed by a self-survey.

MAIN OUTCOME

Positive diagnosis of SSD according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5).

RESULTS

Although the patients did not meet the DSM-5 criteria for a functional neurological symptom disorder specifically, SSD diagnosis based on DSM-5 criteria was positive in 32 (64%) patients. In the remaining 18 patients, SSD was considered possible given the high score on diagnostic scales. Physical examination were normal for all. Brain MRI showed unspecific minor white matter hyperintensities in 8/46 patients. Neuropsychological assessment showed exclusively mild impairment of attention in 14 out of 15 tested patients, in discrepancy with their major subjective complaint. Forty-five (90%) patients met criteria for Chronic Fatigue Syndrome. Seventeen (32%) patients were screened positive for mood-anxiety disorders, 19 (38%) had a history of prior SSD and 27 (54%) reported past trauma. Additional self-survey highlighted post-traumatic stress disorder in 12/43 (28%), high levels of alexithymia traits and perfectionism. Long-lasting symptoms had a major impact with a high rate of insomnia (29/43, 67%), psychiatric follow-up (28/50, 56%) and work or pay loss (25/50, 50%).

CONCLUSION

A majority of patients with unexplained long-lasting neurological symptoms after mild COVID met diagnostic criteria for SSD and may require specific management.

TRIAL REGISTRATION NUMBER

NCT04889313.

Gastrointestinal manifestations of long COVID: A systematic review and meta-analysis

BACKGROUND

Prolonged symptoms after COVID-19 are an important concern due to the large numbers affected by the pandemic.

OBJECTIVES

To ascertain the frequency of gastrointestinal (GI) manifestations as part of long GI COVID.

DESIGN

A systematic review and meta-analysis of studies reporting GI manifestations in long COVID was performed.

DATA SOURCES AND METHODS

Electronic databases (Medline, Scopus, Embase, Cochrane Central Register of Controlled Trials, and Web of Science) were searched till 21 December 2021 to identify studies reporting frequency of GI symptoms in long COVID. We included studies reporting overall GI manifestations or individual GI symptoms as part of long COVID. We excluded pediatric studies and those not providing relevant information. We calculated the pooled frequency of various symptoms in all patients with COVID-19 and also in those with long COVID using the inverse variance approach. All analysis was done using R version 4.1.1 using packages 'meta' and 'metafor'.

RESULTS

A total of 50 studies were included. The frequencies of GI symptoms were 0.12 [95% confidence interval (CI), 0.06-0.22, I ² = 99%] and 0.22 (95% CI, 0.10-0.41, I ² = 97%) in patients with COVID-19 and those with long COVID, respectively. The frequencies of abdominal pain, nausea/vomiting, loss of appetite, and loss of taste were 0.14 (95% CI, 0.04-0.38, I ² = 96%), 0.06 (95% CI, 0.03-0.11, I ² = 98%), 0.20 (95% CI, 0.08-0.43, I ² = 98%), and 0.17 (95% CI, 0.10-0.27, I ² = 95%), respectively, after COVID-19. The frequencies of diarrhea, dyspepsia, and irritable bowel syndrome were 0.10 (95% CI, 0.04-0.23, I ² = 98%), 0.20 (95% CI, 0.06-0.50, I ² = 97%), and 0.17 (95% CI, 0.06-0.37, I ² = 96%), respectively.

CONCLUSION

GI symptoms in patients were seen in 12% after COVID-19 and 22% as part of long COVID. Loss of appetite, dyspepsia, irritable bowel syndrome, loss of taste, and abdominal pain were the five most common GI symptoms of long COVID. Significant heterogeneity and small number of studies for some of the analyses are limitations of the systematic review.

Long COVID symptomatology after twelve months and its impact on quality of life according to initial COVID-19 disease severity

Background

“Long COVID” is characterized by a variety of symptoms and an important burden for affected people. Our objective was to describe long COVID symptomatology according to initial coronavirus disease 2019 (COVID-19) severity.

Methods

Predi-COVID cohort study participants, recruited at the time of acute COVID-19 infection, completed a detailed 12-month symptom and quality of life questionnaire. Frequencies and co-occurrences of symptoms were assessed.

Results

Among the 289 participants who fully completed the 12-month questionnaire, 59.5% reported at least 1 symptom, with a median of 6 symptoms. Participants with an initial moderate or severe acute illness declared more frequently 1 or more symptoms (82.6% vs 38.6%, P < .001) and had on average 6.8 more symptoms (95% confidence interval, 4.18–9.38) than initially asymptomatic participants who developed symptoms after the acute infection. Overall, 12.5% of the participants could not envisage coping with their symptoms in the long term. Frequently reported symptoms, such as neurological and cardiovascular symptoms, but also less frequent ones such as gastrointestinal symptoms, tended to cluster.

Conclusions

Frequencies and burden of symptoms present 12 months after acute COVID-19 infection increased with the severity of the acute illness. Long COVID likely consists of multiple subcategories rather than a single entity. This work will contribute to the better understanding of long COVID and to the definition of precision health strategies.

Clinical Trials Registration

NCT04380987.

Long COVID and the cardiovascular system - elucidating causes and cellular mechanisms in order to develop targeted diagnostic and therapeutic strategies: A joint Scientific Statement of the ESC Working Groups on Cellular Biology of the Heart and Myocardial & Pericardial Diseases

Long COVID has become a world-wide, non-communicable epidemic, caused by long-lasting multi-organ symptoms that endure for weeks or months after SARS-CoV-2 infection has already subsided. This scientific document aims to provide insight into the possible causes and therapeutic options available for the cardiovascular manifestations of long COVID. In addition to chronic fatigue, which is a common symptom of long COVID, patients may present with chest pain, ECG abnormalities, postural orthostatic tachycardia, or newly developed supraventricular or ventricular arrhythmias. Imaging of the heart and vessels has provided evidence of chronic, post-infectious peri-myocarditis with consequent left or right ventricular failure, arterial wall inflammation or micro-thrombosis in certain patient populations. Better understanding of the underlying cellular and molecular mechanisms of long COVID will aid in the development of effective treatment strategies for its cardiovascular manifestations. A number of mechanisms have been proposed, including those involving direct effects on the myocardium, micro-thrombotic damage to vessels or endothelium, or persistent inflammation. Unfortunately, existing circulating biomarkers, coagulation and inflammatory markers, are not highly predictive for either the presence or outcome of long COVID when measured 3 months after SARS-CoV-2 infection. Further studies are needed to understand underlying mechanisms, identify specific biomarkers and guide future preventive strategies or treatments to address long COVID and its cardiovascular sequelae.

Clinical Characteristics and Mechanisms of Musculoskeletal Pain in Long COVID

Objective

Musculoskeletal (MSK) pain is being increasingly reported by patients as one of the most common persistent symptoms in post-COVID-19 syndrome or Long COVID. However, there is a lack of understanding of its prevalence, characteristics, and underlying pathophysiological mechanisms. The objective of this review is to identify and describe the features and characteristics of MSK pain in Long COVID patients.

Methods

The narrative review involved a literature search of the following online databases: MEDLINE (OVID), EMBASE (OVID), CINAHL, PsyclNFO, and Web of Science (December 2019 to February 2022). We included observational studies that investigated the prevalence, characteristics, risk factors and mechanisms of MSK pain in Long COVID. After screening and reviewing the initial literature search results, a total of 35 studies were included in this review.

Results

The overall reported prevalence of MSK pain in Long COVID ranged widely from 0.3% to 65.2%. The pain has been reported to be localized to a particular region or generalized and widespread. No consistent pattern of progression of MSK pain symptoms over time was identified. Female gender and higher BMI could be potential risk factors for Long COVID MSK pain, but no clear association has been found with age and ethnicity. Different pathophysiological mechanisms have been hypothesized to contribute to MSK pain in Long COVID including increased production of proinflammatory cytokines, immune cell hyperactivation, direct viral entry of neurological and MSK system cells, and psychological factors.

Conclusion

MSK pain is one of the most common symptoms in Long COVID. Most of the current literature on Long COVID focuses on reporting the prevalence of persistent MSK pain. Studies describing the pain characteristics are scarce. The precise mechanism of MSK pain in Long COVID is yet to be investigated. Future research must explore the characteristics, risk factors, natural progression, and underlying mechanisms of MSK pain in Long COVID.

Smoking increases the risk of post-acute COVID-19 syndrome: Results from a French community-based survey

INTRODUCTION

METHODS

RESULTS

CONCLUSIONS

Post-COVID-19 syndrome, low-grade inflammation and inflammatory markers: a cross-sectional study

OBJECTIVE

Post-COVID syndrome (PCS) is a poorly known entity. An underlying chronic, low-grade inflammation (LGI) has been theorized as a pathophysiological mechanism. Available data on biomarkers in PCS show conflicting results. Our aim was to know whether subjects with PCS present higher levels of inflammatory markers, after a mild COVID-19.

METHODS

Analytical cross-sectional study. Cases of mild COVID-19 in a community setting were included. We collected epidemiological data (age, sex, BMI, smoking, comorbidities), variables of the acute COVID-19 (duration, symptoms), and data at 3 months after the acute phase (symptoms and laboratory test). Serum C-reactive protein (CRP), neutrophil and lymphocyte counts, neutrophil/lymphocyte ratio (NLR), lactate dehydrogenase, ferritin, fibrinogen, and D-dimer levels were analysed. LGI was defined as CRP >0.3 and <1.0 mg/dL. A subject was classified as PCS + if presented signs and symptoms >12 weeks after an infection consistent with COVID-19. Five composite indices (C1-C5) were developed, combining the upper ranges of biomarkers distributions. Multivariate analyses were performed.

RESULTS

We analysed 121 mild COVID-19 cases (mean age = 45.7 years, 56.2% women). Among the acute symptoms, women presented a higher frequency of fatigue (54.4% vs 30.2%; p = .008). PCS affected 35.8% of women and 20.8% of men (p = .07), and the most reported symptoms were fatigue (42.8%), anosmia (40%), ageusia (22.8%), dyspnea (17.1%) and myalgia (11.4%). Neutrophil count, NLR, CRP and fibrinogen showed the best correlations with PCS and were selected to develop the indices. In women PCS+, C1, C3 and C4 indices were more frequently met, while in men PCS+, C2, C5 and CRP were in the range of LGI. Anosmia, ageusia and fatigue were related to higher neutrophil counts, with sex differences. Fibrinogen levels were higher in persistent myalgia (510 ± 82 mg/dL vs 394 ± 87; p = .013). In multivariable analysis, a woman with a neutrophil count above the median, or with fibrinogen level or NLR in the highest tertile, had a 4-5-fold increased risk of prevalent PCS. A man with CRP in the range of LGI, or fibrinogen level or a neutrophil count in the highest tertile, had a 10-17-fold increased risk of prevalent PCS.

CONCLUSIONS

The data obtained in the present cross-sectional study seems to demonstrate a consistent association between PCS and upper ranges of the neutrophil count, NLR, fibrinogen, and CRP in the LGI range. Furthermore, composite indices appear useful in detecting relationships between slight elevations of biomarkers and PCS, and our study identifies relevant sex differences in symptoms and markers regarding the PCS.

COVID-19 and the Brain

Entering the third year into the pandemic, overwhelming evidence demonstrates that Coronavirus disease 2019 (COVID-19) infection is a systemic illness, often with involvement of the central nervous system. Multiple mechanisms may underlie the development of neurologic manifestations of illness, including hypoxia, systemic illness, hypercoagulability, endothelial dysfunction, general critical illness, inflammatory response, and neurotropism of the severe acute respiratory syndrome coronavirus 2 (SARS-Co-V2) virus. COVID-19 infection is associated with neurologic involvement in all stages; acute infection, subacute/post-infection, and growing evidence also suggests during a chronic phase, the post-acute sequalae of COVID-19 (PASC). With over 20,000 published articles on COVID and the brain at the time of writing, it is virtually impossible to present an unbiased comprehensive review of how SARS-Co-V2 impacts the nervous system. In this review, we will present an overview of common neurologic manifestations, in particular focusing on the cerebrovascular complications, and proposed pathophysiology.

A CLASSIFICATION SYSTEM FOR POST-ACUTE SEQUELAE OF SARS CoV-2 INFECTION

This study aimed to contribute to the development of a research case definition for post-acute sequelae of SARS CoV-2 infection (PASC) using a PASC data set and experiences from case definitions developed for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).  Our database included patients with PASC who provided self-report symptomology during the onset of infection and the time of survey completion (post-infection).  We found that we could distinguish between those with mild, moderate, and severe PASC.  Regarding the proportion meeting an ME/CFS case definition, we found 0% in the mildly impaired group, 30.6% to 62.6% in the moderately impaired group, and 74.3% to 89.0% in the severely impaired group. Based on these preliminary data, we propose a 5-part classification system for PASC.  Axis 1 involves the variant of the COVID infection and the type of documentation of the infection. Axis 2 involves the time elapsed since infection. Axis 3 involves the type of medical collateral damage to different organs. Axis 4 involves functional impairment classified into three categories: mild, moderate, or severe.  Finally, Axis 5 is the identified symptoms. Finally, if the patient has been sick for 6 or more months, it is important to determine whether the person has met the ME/CFS criteria.  This proposed 5-part classification system for PASC might bring considerable clarity to diagnosing PASC.   

Understanding Long Covid: Nosology, social attitudes and stigma

The debate around Long Covid has so far shown resistance to accept parallels between Long Covid and a set of existing conditions which have historically been subject to stigma. This resistance risks endorsing the stigma associated with such existing conditions, and as such, these dynamics of stigma ought to be dismantled in order to facilitate the development of effective clinical resources for all such implicated conditions. As well as affecting proceedings at the structural level, I discuss how the aforementioned problems also risk affecting patients at the personal level by motivating the reconfiguration and restriction of patient illness narratives. The problems I identify therefore risk affecting both collective and individual understanding of Long Covid.

[Postcovid cognitive impairment]

This review addresses current issues in post-COVID syndrome with a focus on neurocognitive impairment. The results of studies on complications in patients of different ages and health statuses recovered from mild to severe COVID-19 are discussed. Current data on the pathogenetic mechanisms of the development of various post-COVID disorders are presented, including a detailed discussion of central nervous system damage. The paper summarizes data on the relationship between neurocognitive disorders and accelerated cell aging, chronic nonspecific inflammation, and reduced neuroplasticity in the central nervous system. The main pathogenetic ways to prevent COVID-related complications, including neuronal tissue damage and the prospects for managing such patients are discussed. The choice of pathogenetic therapy in patients with neurocognitive impairment in the post-COVID period is assessed. The main benefits of choline alfoscerate therapy for neurocognitive impairment in patients with post-COVID syndrome are discussed.

[Mechanisms underlying chronic fatigue, a symptom too often overlooked II- From deregulated immunity to neuroinflammation and its consequences]

Hypothalamus stimulation by inflammatory and / or stress signals can trigger activation of the HPA (hypothalamic-pituitary-adrenal) axis, which includes the hypothalamus, pituitary and adrenal gland. Acute activation of the HPA axis is fundamental for the fight or flight response. It allows a maximal energy mobilization available for an effort, whilst erasing fatigue. On the contrary, the chronic activation of this axis decreases muscle efficiency and leads to chronic fatigue. In this second part of our review will be discussed several strategic points that need to be considered for attempting to understand and treat together inflammation and chronic fatigue.

Persistent headache after COVID-19: Pathophysioloy, clinic and treatment

SARS-CoV-2 is the virus responsible for the COVID-19 pandemic. The acute infection is characterised not only by respiratory symptoms, but also by multiple systemic manifestations, including neurological symptoms. Among these, headache is a frequent complaint. As the pandemic progresses and the population of patients recovering from COVID-19 grows, it is becoming apparent that the headache present in the acute stage of the infection may persist for an indeterminate period, becoming a major problem for the patient and potentially leading to disability. In this review we describe the pathophysiological and clinical aspects of persistent headache after COVID-19 based on the information currently available in the literature and the authors' clinical experience.

Post-COVID symptoms of potential peripheral nervous and muscular origin

Many patients report persistent symptoms attributable to dysfunction of the peripheral nervous and muscular systems after acute COVID-19. These symptoms may constitute part of the so-called post-acute COVID-19 syndrome (PACS), or may result from neuromuscular complications of hospitalisation in intensive care units (ICUs). This article provides an updated review of symptoms of potential neuromuscular origin in patients with PACS, differentiating symptoms according to muscle, peripheral nerve, or autonomic nervous system involvement, and analyses the forms of neuromuscular involvement in patients who were admitted to the ICU due to severe COVID-19.

Characterization and Pathogenic Speculation of Xerostomia Associated with COVID-19: A Narrative Review

Patients with coronavirus disease 2019 (COVID-19) have become known to present with different oral symptoms. However, xerostomia remains poorly recognized compared with taste dysfunction. For better understanding of COVID-19 symptomatology, xerostomia associated withCOVID-19 was characterized and its possible pathogenesis was speculated by a narrative literature review. Scientific articles were retrieved by searching PubMed, LitCovid, ProQuest, Google Scholar, medRxiv and bioRxiv from 1 April 2020 with a cutoff date of 30 September 2021. Results of the literature search indicated that xerostomia is one of prevalent and persistent oral symptoms associated with COVID-19. In contrast to taste dysfunction, the prevalence and persistence of xerostomia do not necessarily depend on ethnicity, age, gender and disease severity of patients. COVID-19 xerostomia is pathogenically related to viral cellular entry-relevant protein expression, renin-angiotensin system disturbance, salivary gland inflammation, zinc deficiency, cranial neuropathy, intercurrent taste dysfunction, comorbidities and medications. Despite a close association with COVID-19, xerostomia, dry mouth and hyposalivation tend to be overlooked unlike ageusia, dysgeusia and hypogeusia. Although mouth dryness per se is not life-threating, it has an impact on the oral health-related quality of life. More attention should be paid to xerostomia in COVID-19 patients and survivors.

Autoimmune Encephalitis Post-SARS-CoV-2 Infection: Case Frequency, Findings, and Outcomes

Background and Objectives

Autoimmune encephalitis (AE) cases after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, but the frequency is unknown. We aimed to determine the frequency and diagnostic features of coronavirus disease 2019 (COVID-19)–related AE.

Methods

Residual sera from 556 consecutive Mayo Clinic Rochester patients (laboratory cohort) who underwent autoimmune encephalopathy neural immunoglobulin G (IgG) evaluation were tested for total antibodies against the SARS-CoV-2 spike glycoprotein using a Food and Drug Administration–authorized chemiluminescence assay (October 2019–December 2020). Clinical records from patients with a positive SARS-CoV-2 antibody result and available research consent were reviewed. This laboratory cohort was cross-referenced with the Department of Neurology's COVID-19–related consultative experience (encephalopathy cohort, n = 31).

Results

Eighteen of the laboratory cohort (3%) were SARS-CoV-2 antibody positive (April–December 2020). Diagnoses were as follows: AE, 2; postacute sequelae of SARS CoV-2 infection (PASC), 3; toxic-metabolic encephalopathy during COVID-19 pneumonia, 2; diverse non–COVID-19 relatable neurologic diagnoses, 9; unavailable, 2. Five of the encephalopathy cohort had AE (16%, including the 2 laboratory cohort cases that overlapped), representing 0.05% of 10,384 patients diagnosed and cared for with any COVID-19 illness at Mayo Clinic Rochester in 2020. The 5 patients met definite (n = 1), probable (n = 1), or possible (n = 3) AE diagnostic criteria; median symptom onset age was 61 years (range, 46–63); 3 were women. All 5 were neural IgG negative and 4 tested were SARS-CoV-2 PCR/IgG index negative in CSF. Phenotypes (and accompanying MRI and EEG findings) were diverse (delirium [n = 5], seizures [n = 2], rhombencephalitis [n = 1], aphasia [n = 1], and ataxia [n = 1]). No acute disseminated encephalomyelitis cases were encountered. The 3 patients with possible AE had spontaneously resolving syndromes. One with definite limbic encephalitis was immune therapy responsive but had residual mood and memory problems. One patient with probable autoimmune rhombencephalitis died despite immune therapy. The remaining 26 encephalopathy cohort patients had toxic-metabolic diagnoses.

Discussion

We encountered occasional cases of AE in our 2020 COVID-19 experience. Consistent with sporadic reports and small case series during the COVID-19 pandemic, and prior experience of postinfectious AE, our cases had diverse clinical presentations and were neural IgG and CSF viral particle negative. Application of diagnostic criteria assists in differentiation of AE from toxic-metabolic causes arising in the setting of systemic infection.

Long COVID or post-COVID-19 syndrome: putative pathophysiology, risk factors, and treatments

Long COVID or post-COVID-19 syndrome first gained widespread recognition among social support groups and later in scientific and medical communities. This illness is poorly understood as it affects COVID-19 survivors at all levels of disease severity, even younger adults, children, and those not hospitalized. While the precise definition of long COVID may be lacking, the most common symptoms reported in many studies are fatigue and dyspnoea that last for months after acute COVID-19. Other persistent symptoms may include cognitive and mental impairments, chest and joint pains, palpitations, myalgia, smell and taste dysfunctions, cough, headache, and gastrointestinal and cardiac issues. Presently, there is limited literature discussing the possible pathophysiology, risk factors, and treatments in long COVID, which the current review aims to address. In brief, long COVID may be driven by long-term tissue damage (e.g. lung, brain, and heart) and pathological inflammation (e.g. from viral persistence, immune dysregulation, and autoimmunity). The associated risk factors may include female sex, more than five early symptoms, early dyspnoea, prior psychiatric disorders, and specific biomarkers (e.g. D-dimer, CRP, and lymphocyte count), although more research is required to substantiate such risk factors. While preliminary evidence suggests that personalized rehabilitation training may help certain long COVID cases, therapeutic drugs repurposed from other similar conditions, such as myalgic encephalomyelitis or chronic fatigue syndrome, postural orthostatic tachycardia syndrome, and mast cell activation syndrome, also hold potential. In sum, this review hopes to provide the current understanding of what is known about long COVID.

Long-term Outcome of Chilblains Associated with SARS-CoV-2

Numerous cases of chilblains have been observed in the course if the COVID-19 pandemic. The aims of this study were to provide comprehensive follow-up data for patients reporting chilblains, and to determine the risk factors for incomplete recovery. Patients referred to 5 hospitals in France between March and May 2020 for chilblains were surveyed on December 2020. A teleconsultation was offered. Among 82 patients reporting chilblains, 27 (33%) reported complete recovery, 33 (40%) had recurrences of chilblains after their hands and feet had returned to normal, and 22 (27%) developed persistent acral manifestations, mostly acrocyanosis, with or without further recurrences of chilblains. Most recurrences of chilblains occurred during the following autumn and winter. A past history of chilblains was not associated with recurrences or persistent acral manifestations. Women had a significantly higher risk of developing recurrences or persistent acral manifestations (odds ratio 1.30; 95% confidence interval 1.06–1.59). In conclusion, two-thirds of patients reporting chilblains at the start of the COVID-19 pandemic experienced persistent or recurrent acral manifestations after a 10-month follow-up.

Post-akutes COVID-19 (“long-COVID”): Andauernde Symptome, mögliche Ursachen und symptomgeleitetes post-akut COVID-19 Management zur Wiedererlangung der körperlichen Leistungsfähigkeit (Scoping Review)

Das schwere akute respiratorische Syndrom Coronavirus 2 (SARS-CoV-2) ist der Erreger der pandemischen Erkrankung COVID-19, für die nach mehr als einem Jahr erkennbar ist, dass nach einer überstandenen akuten Erkrankung andauernde Symptome existieren können. Als post-akutes COVID-19 werden das Anhalten klinischer Symptome und/oder das Auftreten langfristiger Komplikationen über 4 Wochen nach der akut symptomatischen Krankheitsphase hinaus definiert. Aussagen über die Prävalenz sind vorläufig und abhängig vom Betrachtungszeitraum und untersuchter Bevölkerungsgruppe. In der Allgemeinbevölkerung wird das Auftreten derzeit mit einem Anteil von 15-30% der Infizierten angegeben. Die angegebenen Symptome lassen sich einer Vielzahl von Organsystemen zuordnen und weisen, was Anzahl, Dauer und Schweregrad anbelangt, teilweise große, interindividuelle Unterschiede auf. Die Ursachen für die subakute und chronische Manifestation der Symptome sind noch ungeklärt und verschiedene Mechanismen, wie funktionelle Einschränkungen multipler Organsysteme durch Gewebeschädigung sowie eine postivirale Autoimmunität werden diskutiert. Cluster aus möglichen individuellen Risikofaktoren, wie Alter und Geschlecht, kombiniert mit den Symptomen in der Akutphase zeigen sich am vielversprechendsten, um die Entwicklung von post-akutem COVID-19 zu prognostizieren. Ziel des Scoping Reviews ist es, andauernde Symptome und mögliche Ursachen für post-akutes COVID-19 (”long-COVID“) zusammenzufassen und wesentliche Aspekte für ein post-akutes COVID-19-Management zur Wiedererlangung der körperlichen Leistungsfähigkeit evidenzbasiert einzuordnen.

[Patient experience, epistemic authority and health challenges: the example of long COVID]

Since February 2020, hundreds of thousands of patients have been left with persistant symptoms after their infection. Along with their clinicians, these patients are exposed to a high degree of uncertainty and the urgent need to produce conceptual frameworks aimed at recognising, treating and validating their experience as patients suffering from new and protracted symptoms and witnessing debates as to how these symptoms should be qualified. In this respect, long covid illustrates the need to combine the collective experiential knowledge of patients and scientific knowledge for the benefit of the patients, clinicians and research.

Characterizing long COVID in an international cohort: 7 months of symptoms and their impact

BACKGROUND

A significant number of patients with COVID-19 experience prolonged symptoms, known as Long COVID. Few systematic studies have investigated this population, particularly in outpatient settings. Hence, relatively little is known about symptom makeup and severity, expected clinical course, impact on daily functioning, and return to baseline health.

METHODS

We conducted an online survey of people with suspected and confirmed COVID-19, distributed via COVID-19 support groups (e.g. Body Politic, Long COVID Support Group, Long Haul COVID Fighters) and social media (e.g. Twitter, Facebook). Data were collected from September 6, 2020 to November 25, 2020. We analyzed responses from 3762 participants with confirmed (diagnostic/antibody positive; 1020) or suspected (diagnostic/antibody negative or untested; 2742) COVID-19, from 56 countries, with illness lasting over 28 days and onset prior to June 2020. We estimated the prevalence of 203 symptoms in 10 organ systems and traced 66 symptoms over seven months. We measured the impact on life, work, and return to baseline health.

FINDINGS

For the majority of respondents (>91%), the time to recovery exceeded 35 weeks. During their illness, participants experienced an average of 55.9+/- 25.5 (mean+/-STD) symptoms, across an average of 9.1 organ systems. The most frequent symptoms after month 6 were fatigue, post-exertional malaise, and cognitive dysfunction. Symptoms varied in their prevalence over time, and we identified three symptom clusters, each with a characteristic temporal profile. 85.9% of participants (95% CI, 84.8% to 87.0%) experienced relapses, primarily triggered by exercise, physical or mental activity, and stress. 86.7% (85.6% to 92.5%) of unrecovered respondents were experiencing fatigue at the time of survey, compared to 44.7% (38.5% to 50.5%) of recovered respondents. 1700 respondents (45.2%) required a reduced work schedule compared to pre-illness, and an additional 839 (22.3%) were not working at the time of survey due to illness. Cognitive dysfunction or memory issues were common across all age groups (~88%). Except for loss of smell and taste, the prevalence and trajectory of all symptoms were similar between groups with confirmed and suspected COVID-19.

INTERPRETATION

Patients with Long COVID report prolonged, multisystem involvement and significant disability. By seven months, many patients have not yet recovered (mainly from systemic and neurological/cognitive symptoms), have not returned to previous levels of work, and continue to experience significant symptom burden.

FUNDING

All authors contributed to this work in a voluntary capacity. The cost of survey hosting (on Qualtrics) and publication fee was covered by AA's research grant (Wellcome Trust/Gatsby Charity via Sainsbury Wellcome center, UCL).

["Long-haul COVID": An opportunity to address the complexity of post-infectious functional syndromes]

In this work, we address the issue of prolonged symptoms following an infection by SARS-CoV-2, labeled "long COVID". This clinically unspecific syndrome must be put in perspective with the post-infectious syndromes known for a long time but ultimately poorly understood and little studied, qualified, for lack of convincing arguments for a unambiguous pathophysiology and better terms, as functional somatic syndromes. The clinical implications for clinical care ("holistic" work-up and care of patients), for research (need for truly "bio-psycho-social" investigations), and the social implications of "long COVID" (social construction of the syndrome through the experiences of patients exposed on social networks, inequalities in the face of the disease and its socioeconomic consequences) are considered. "Long COVID" must be view, because of its expected prevalence, as an opportunity to address the complexity of post-infectious (functional) syndromes, their risk factors, and the biological, psychological and social mechanisms underlying them.

Insights into SARS-CoV-2 Persistence and Its Relevance

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), continues to wreak havoc, threatening the public health services and imposing economic collapse worldwide. Tailoring public health responses to the SARS-CoV-2 pandemic depends on understanding the mechanism of viral replication, disease pathogenesis, accurately identifying acute infections, and mapping the spreading risk of hotspots across the globe. However, effective identification and isolation of persons with asymptomatic and mild SARS-CoV-2 infections remain the major obstacles to efforts in controlling the SARS-CoV-2 spread and hence the pandemic. Understanding the mechanism of persistent viral shedding, reinfection, and the post-acute sequalae of SARS-CoV-2 infection (PASC) is crucial in our efforts to combat the pandemic and provide better care and rehabilitation to survivors. Here, we present a living literature review (January 2020 through 15 March 2021) on SARS-CoV-2 viral persistence, reinfection, and PASC. We also highlight potential areas of research to uncover putative links between viral persistence, intra-host evolution, host immune status, and protective immunity to guide and direct future basic science and clinical research priorities.

Parameters associated with diagnosis of COVID-19 in emergency department

OBJECTIVES

We designed this study to identify laboratory and radiological parameters, which could be useful to guide the clinician, in the evaluation of a suspected case of coronavirus disease 19 (COVID-19).

METHODS

This retrospective, observational, single-center-study recruited patients with a suspect of COVID-19 data were extracted from electronic medical records using a standardized data collection form.

RESULTS

A total of 566 patients with suspect COVID-19 infection were enrolled (280 were COVID-19+). The COVID-19 population was characterized with bilateral-pneumonia, a lower count of neutrophil, lymphocyte and monocyte, a lower neutrophil to lymphocyte-ratio (NLR). Lower of platelet count, d-dimer, troponin I, and serum calcium were in COVID-19 patients. The occurrence of COVID-19 diagnosis increased, independently of other variables, with pneumonia (odds ratio [OR]: 3.60; p < .001), neutrophil below normal range (OR: 4.15; p < .05), lactate dehydrogenase (OR: 2.09; p < .01) and sodium above normal range (OR: 2.34; p < .01). In patients with possible respiratory acute affections we found a higher neutrophil, higher monocyte, a higher NLR and a more elevation in d-dimer. In the Sepsis group showed higher level of white blood cell, C-reactive protein, d-dimer, and procalcitonin.

CONCLUSIONS

Our study confirms that patients with COVID-19 have typical radiological and laboratory characteristics. The parameters highlighted in the study can help identify COVID-19 patients, also highlighting which are the main differential diagnoses to be made and the parameters that facilitate the differential diagnosis.

Persistent Brainstem Dysfunction in Long-COVID: A Hypothesis

Long-COVID is a postviral illness that can affect survivors of COVID-19, regardless of initial disease severity or age. Symptoms of long-COVID include fatigue, dyspnea, gastrointestinal and cardiac problems, cognitive impairments, myalgia, and others. While the possible causes of long-COVID include long-term tissue damage, viral persistence, and chronic inflammation, the review proposes, perhaps for the first time, that persistent brainstem dysfunction may also be involved. This hypothesis can be split into two parts. The first is the brainstem tropism and damage in COVID-19. As the brainstem has a relatively high expression of ACE2 receptor compared with other brain regions, SARS-CoV-2 may exhibit tropism therein. Evidence also exists that neuropilin-1, a co-receptor of SARS-CoV-2, may be expressed in the brainstem. Indeed, autopsy studies have found SARS-CoV-2 RNA and proteins in the brainstem. The brainstem is also highly prone to damage from pathological immune or vascular activation, which has also been observed in autopsy of COVID-19 cases. The second part concerns functions of the brainstem that overlap with symptoms of long-COVID. The brainstem contains numerous distinct nuclei and subparts that regulate the respiratory, cardiovascular, gastrointestinal, and neurological processes, which can be linked to long-COVID. As neurons do not readily regenerate, brainstem dysfunction may be long-lasting and, thus, is long-COVID. Indeed, brainstem dysfunction has been implicated in other similar disorders, such as chronic pain and migraine and myalgic encephalomyelitis or chronic fatigue syndrome.