Pathophysiology and mechanism of long COVID: a comprehensive review

Post-acute sequelae of SARS-CoV-2 infection (Long COVID) in older adults

Long COVID, also known as PASC (post-acute sequelae of SARS-CoV-2), is a complex infection-associated chronic condition affecting tens of millions of people worldwide. Many aspects of this condition are incompletely understood. Among them is how this condition may manifest itself in older adults and how it might impact the older population. Here, we briefly review the current understanding of PASC in the adult population and examine what is known on its features with aging. Finally, we outline the major gaps and areas for research most germane to older adults.

Caring for Long Covid patients in primary healthcare: a cross-sectional study on general practitioners' knowledge, perception and experience in Belgium and Malta

BACKGROUND

At least 10% of Covid-19 recovered individuals experience persistent symptoms (Long Covid). Primary healthcare and general practitioners (GPs) are at the forefront in their care. In this study, GPs' knowledge, perceptions and experiences with Long Covid, and the definition used in two countries, are investigated to provide insight into GPs' care for Long Covid patients at a cross-country level.

METHODS

A cross-sectional study targeted towards GPs was conducted in Belgium and Malta during spring and early summer 2022. An online survey consisting of 15 questions on Long Covid was disseminated. Additionally, country-specific practice and demographic characteristics were collected. Descriptive and logistic regression analyses were performed.

RESULTS

A total of 150 GPs (Belgium = 105; Malta = 45) responded. Female GPs represented 58.0%, median age was 49 years (IQR: 37-61). Concerning GPs' knowledge and perception on Long Covid, in both countries, most GPs reported insufficient scientific knowledge and information on Long Covid diagnosis and treatment. Access to educational material was limited and an awareness-rising campaign on Long Covid was deemed necessary. Moreover, two out of three GPs stated that Long Covid patients were not well followed up by primary healthcare in mid-2022. For diagnosing Long Covid, 54.7% required a positive Covid-19 test, more often among Belgian GPs than Maltese (64.3% vs. 45.2%, p = 0.036). To assess Long Covid, GPs mainly applied diagnostic criteria by themselves (47.3%) in combination with persistent symptoms (4 weeks to 5 months). Most GPs had experience with Long Covid patients in their practice, regardless of practice type and GPs' country, sex or age (p = 0.353; p = 0.241; p = 0.194; p = 0.058). Although most GPs (94.7%) stated that Long Covid patients should follow multidisciplinary approach, 48.3% reported providing care for these patients themselves or with GP colleagues and only 29.8% by multidisciplinary cooperation.

CONCLUSIONS

GPs frequently provide (multidisciplinary) care to Long Covid patients and GPs' care showed similarities at cross-country level. Although GPs perceive lack of scientific knowledge and educational material on Long Covid, similar diagnostic criteria among GPs were noted. Uniform evidence-based guidelines, scientific support and training for GP across Europe must be a priority to enhance their treatment approach to Long Covid.

Mapping the landscape of mental health and long COVID: a protocol for scoping review

INTRODUCTION

Mental health concerns are prevalent among adult patients with long COVID (LC), but the current state of knowledge regarding mental health in the context of LC is not fully understood. The objective of this scoping review is to map and summarise the existing research on mental health conditions among LC patients and highlight the knowledge gaps. This review aims to provide a comprehensive overview of the evolving landscape of research in the area.

METHODS AND ANALYSIS

The concept of interest is mental health in adult LC patients. This scoping review will be guided by the Joanna Briggs Institute Manual for Evidence Synthesis and reported according to the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review guidelines. Using predefined search parameters, a comprehensive search of two electronic databases (Medline and APA PsycINFO) and grey literature sources identified 3104 potentially eligible articles published from 1 January 2020 to 4 April 2024. Following the removal of duplicates, 2767 articles were imported for screening in Covidence. The study selection process involves screening titles, abstracts and full text of potentially relevant articles, which will then be analysed using thematic analysis. Data will be extracted using a predefined extraction form.

ETHICS AND DISSEMINATION

Ethical approval is not required because this study does not involve human participants or primary data collection. The findings from this review will be disseminated through a peer-reviewed publication, conference presentations and professional networks. In addition, a summary of the results will be shared with patient partners and other relevant stakeholders.

PUBLIC HEALTH IMPLICATIONS

The findings from this scoping review will contribute to a better understanding of mental health issues arising in LC patients and inform future research directions and public health interventions in this area.

Impact of post-COVID symptoms on activity and participation of women and men

Post-COVID syndrome is affecting many organ systems and arises as a major public health problem with millions of cases worldwide. The primary aim of this study is the analysis of health problems, activity limitations and participation restrictions (ALPR) of participants with post-COVID symptoms and the investigation of correlations between these elements to derive statements about the rehabilitation need, also depending on sex. A retrospective cohort study was performed to collect longitudinal data from January 2022 to January 2023 using the Covid-19 Rehabilitation Needs Questionnaire (RehabNeQ). Patients completed the questionnaire at the Department of Rehabilitation- and Sports Medicine at Hannover Medical School. The 1st assessment included 307 study participants, of whom 54 showed up for the 2nd, 7 for the 3rd and one for the 4th assessment. Study participants with post-COVID symptoms also experience ALPR. The results show no significant difference in symptom intensity in women and men, but in intensity of ALPR. We found many correlations of varying degrees between various factors with ALPR. We found frequent correlations between fatigue and several ALPR. While these correlations apply to both sexes, we also found different correlations in women and men, indicating the different rehabilitation need of women and men.

Prevalence and exploratory factor analysis of long COVID-19 symptoms among experienced infected population in Bangkok, Thailand

BACKGROUND

Patients with long COVID may experience various concomitant symptoms caused by inflammation, which affect their lives and well-being. In this study, we aimed to (1) investigate the prevalence of long COVID; (2) explore the levels of symptom severity and functional disability owing to long COVID, overall health, and their relationship; and (3) conduct exploratory factor analysis of long COVID-19 symptoms among experienced infected population in the capital of Thailand.

METHODS

A cross-sectional research design was used and a sample of 337 community members with previously COVID-19 infection in Bangkok, Thailand was recruited for this study. Purposive sampling was used. Data collection was performed using an online and a paper-based questionnaire. Descriptive statistics (number, percentage), odds ratio, exploratory factor analysis, and Spearman's rank correlation coefficient were used for the data analysis.

RESULTS

The prevalence of long COVID was 32.9%. The main reported symptoms included anxiety (28.5%), fatigue (26.1%), and dyspnea (13.4%). There was a significant relationship between symptom severity and functional disability (rs=0.385, p value < 0.01). Overall health was negatively correlated with symptom severity (rs = - 0.291, p < .01) and functional disability (rs = - 0.108, p < .05). Using principal component analysis with Promax rotation, three clusters were identified, explaining 71.44% of the total variance. The Clusters comprised (1) common symptoms of long COVID and communication, (2) fatigue, functioning, and nutritional concerns, and (3) psychosocial impacts.

CONCLUSIONS

The present results might help multidisciplinary care teams understand the concurrent symptoms of patients with long COVID and develop rehabilitation care programs to ease all symptoms simultaneously and improve patients' quality of life.

Impact of SARS-CoV-2 Infection on Essential Tremor: A Retrospective Clinical and Kinematic Analysis

In the past few years, SARS-CoV-2 infection has substantially impacted public health. Alongside respiratory symptoms, some individuals have reported new neurological manifestations or a worsening of pre-existing neurological conditions. We previously documented two cases of essential tremor (ET) who experienced a deterioration in tremor following SARS-CoV-2 infection. However, the effects of SARS-CoV-2 on ET remain largely unexplored. This study aims to evaluate the impact of SARS-CoV-2 infection on a relatively broad sample of ET patients by retrospectively comparing their clinical and kinematic data collected before and after the exposure to SARS-CoV-2. We surveyed to evaluate the impact of SARS-CoV-2 infection on tremor features in ET. Subsequently, we retrospectively analysed clinical and kinematic data, including accelerometric recordings of postural and kinetic tremor. We included 36 ET patients (14 females with a mean age of 71.1 ± 10.6 years). Among the 25 patients who reported SARS-CoV-2 infection, 11 (44%) noted a subjective worsening of tremor. All patients reporting subjective tremor worsening also exhibited symptoms of long COVID, whereas the prevalence of these symptoms was lower (50%) in those without subjective exacerbation. The retrospective analysis of clinical data revealed a tremor deterioration in infected patients, which was not observed in non-infected patients. Finally, kinematic analysis revealed substantial stability of tremor features in both groups. The study highlighted a potential correlation between the SARS-CoV-2 infection and clinical worsening of ET. Long COVID contributes to a greater impact of tremor on the daily life of ET patients.

Understanding long COVID: prevalence, characteristics, and risk factors in the Eastern Province of Saudi Arabia

Background

The COVID-19 pandemic has significantly raised public health concerns and efforts to limit its spread, impacting societies and health systems worldwide. As challenges persist, the emergence of Long COVID (LC) marks a turning point in understanding the pandemic's long-term effects.

Aim

This study aimed to determine the prevalence of LC in the Eastern Province of the Kingdom of Saudi Arabia (KSA) and explore factors contributing to its persistence.

Methods

This descriptive, cross-sectional, questionnaire-based study was carried out between December 1, 2023, and March 1, 2024, involving 1,355 patients who recovered from COVID-19. Participants were conveniently chosen and information was gathered through in-person interviews in public settings after obtaining consent.

Results

A majority of the patients (N = 1,355; 47.5% female; 93.8% Saudis; mean Age ± SD 33.13 ± 12.60 years) had received three COVID-19 vaccine doses (89.5%). Women experienced 17.4% more LC symptoms than men (p < 0.001). The risk of having a higher symptom count increased by 42.5% 12 months after acute COVID-19 infection compared with baseline (<3 months, p < 0.001). A higher body mass index (BMI) was associated with more symptoms (1.1% increase per unit, p = 0.004). More acute-phase symptoms correlated with more LC symptoms (p < 0.001). Higher educational attainment reduced LC risk by 33% (p < 0.001). Finally, age and vaccination status had no effect on LC symptoms count (p > 0.05).

Conclusion

Sociodemographic and clinical factors contribute differently to the chances of having LC and the count of symptoms. Awareness of such factors could provide insight into improving management, leading to better health outcomes.

Peculiarities of Hemostasis and Proteomics in Patients With Acute Myocardial Infarction and Healthy Volunteers After SARS-CоV-2 Infection

AIM

To identify the features of plasma, platelet hemostasis, and proteomic composition of the blood plasma in patients with acute myocardial infarction (AMI) and healthy volunteers after COVID-19.

MATERIAL AND METHODS

The study included patients with AMI who have recently had COVID-19 (AMI-post-COVID, n=56) and patients with AMI who have not recently had COVID-19 (AMI-control, n=141). Healthy volunteers constituted the control groups and were also divided into control-post-COVID (n=32) and control-control (n=71) groups. Previous SARS-CoV-2 infection was determined by anti-N IgG in the blood serum, the level of which persists for 6-10 months after the disease. Hemostasis was evaluated by thromboelastometry (on whole blood), thrombodynamics (on platelet-poor plasma), fibrinolysis, impedance aggregometry, and proteomic analysis.

RESULTS

The AMI-post-COVID and AMI-control groups had higher values of thrombus growth rate, size and density based on the data of thromboelastometry and thrombodynamics, as well as increased concentrations of the complement system components, proteins regulating the state of the endothelium, and a number of acute-phase and procoagulant proteins compared to the control groups. Furthermore, in the AMI-post-COVID group, compared to the AMI-control group, the thrombus density was lower, and its lysis rates were higher when measured by the thrombodynamics method on platelet-poor plasma, while the platelet aggregation induced by ADP and thrombin was higher. Also, in the control-post-COVID group, compared to the control-control group, the thrombus formation rate was lower, whereas, in contrast, the thrombus size as measured by the thrombodynamics method and the platelet aggregation induced by arachidonic acid and thrombin were higher. In addition, in the AMI-post-COVID group, compared to the AMI-control group, the concentrations of proteins involved in inflammation and hemostasis were lower.

CONCLUSION

Patients with AMI who have recently had COVID-19 are characterized by a less pronounced activation of the immune response compared to patients with AMI who have not had COVID-19. This may be due to long-term chronic inflammation and depletion of components of the immune activation system after SARS-CoV-2 infection. Long-term activation of the hemostasis system in both patients with AMI and healthy volunteers after COVID-19 is primarily due to the platelet component of hemostasis.

Long COVID among healthcare workers: a narrative review of definitions, prevalence, symptoms, risk factors and impacts

INTRODUCTION

Long COVID (LC) occurs when people experience symptoms for weeks, months or even years after a COVID-19 infection. This review looks at research exploring the LC definitions, prevalence, symptoms, risk factors, and associated impacts in research on healthcare workers (HCWs).

DATA SOURCES

We systematically searched five electronic databases (CINAHL, EMBASE, Medline, PsycInfo and PubMed) and compiled a narrative literature review based on 56 relevant studies.

AREAS OF AGREEMENT

LC is prevalent among HCWs who become infected by COVID-19. Many of the most frequent symptoms associated with LC in the general population are also reported among HCWs. Some risk factors for LC are also similar to those in the general population, such as female sex, older age, and having a pre-existing respiratory illness.

AREAS OF CONTROVERSY

The mechanism(s) responsible for LC remains unknown. A variety of terms, timeframes and symptoms are used to define LC, creating difficulties in comparing results across studies. Much of the research is cross-sectional and fails to explore the impacts that prolonged symptoms have on HCWs' personal and professional lives.

GROWING POINTS

The need to support HCWs with LC is clear. Identifying the mechanism(s) responsible for LC is a key priority, as this will inform treatments.

AREAS FOR DEVELOPING RESEARCH

Future research should move towards a standard definition for LC. Greater attention should be paid to longitudinal and qualitative studies, which could give insights into prognosis, lived experience and work participation. Finally, studies evaluating treatments suitable for people with LC are timely.

Utilization frequency and patient-reported effectiveness of symptomatic therapies in post-COVID syndrome

BACKGROUND

To date there is no causal treatment for post-COVID syndrome, leaving symptomatic treatments as the primary recourse. However, the practical implementation and effectiveness of these interventions remain underexplored. This study aimed to investigate the utilization frequency of symptomatic therapies and patient-reported effectiveness across various treatment modalities at a German post-COVID center.

METHODS

As the baseline investigation we conducted a single-cohort retrospective study to analyze the frequency of symptomatic therapies among post-COVID patients who attended the post-COVID center of the University Hospital of Erlangen, between December 2022 to July 2023. Additionally, we administered a follow-up at least 3 months after the initial presentation, using a questionnaire to assess patient-reported improvements in post-COVID symptoms associated with the symptomatic therapies received.

RESULTS

Our study included 200 patients (mean age: 44.6 ± 12.6 years; 69.0% women; mean duration since acute infection: 15.3 ± 8.3 months). Pharmacotherapy was the predominant symptomatic treatment (79.5%), with psychotropic drugs (32.5%) and analgesics (31.5%) being the most frequently prescribed. Over half of the patients (55.5%) utilized vitamins and nutritional supplements. Hospital admission rates to acute care occurred in 35.5% of cases; 33.0% underwent inpatient rehabilitation and 31.0% pursued outpatient psychotherapy. Cardiologists (76.5%), pulmonologists (67.5%), and neurologists (65.5%) were the most consulted specialists. Therapies involving medical devices were infrequently employed (12.0%). In a follow-up questionnaire (response rate: 82.5%, 6.3 ± 2.2 months post-baseline), beta-blockers were the most effective pharmacological intervention with 31.5% of patients reporting strong to very strong symptom improvement, followed by antibiotics (29.6%). Furthermore, 33.0% of the patients perceived plasmapheresis to strongly alleviate symptoms. Only a small proportion of the sample attributed a strong or very strong symptom improvement to outpatient psychotherapy (11.0%).

CONCLUSION

This study provides initial insights into symptomatic therapy utilization and patient-reported symptom improvement in post-COVID syndrome. Further research into symptoms clusters and interdisciplinary collaboration are warranted to comprehensively address the multifaceted physical and psychological symptomatology.

TRIAL REGISTRATION

The study was registered at the German Clinical Trials Register (DRKS-ID: DRKS00033621) on March 20, 2024.

Incidence, symptom clusters and determinants of post-acute COVID symptoms: a population-based surveillance in community-dwelling users of the COVID RADAR app

OBJECTIVES

This study aims to describe the incidence, symptom clusters and determinants of post-acute COVID symptoms using data from the COVID RADAR app in the Netherlands.

DESIGN

Prospective cohort.

SETTING

General population in the Netherlands from April 2020 to February 2022.

PARTICIPANTS

A total of 1478 COVID RADAR app users, with data spanning 40 days before to 100 days after positive SARS-CoV-2 test.

OUTCOME MEASURES

Incidence and duration of 10 new symptoms that developed during acute infection, defined as 10 days prior and 10 days after positive test. Clustering of these post-acute COVID symptoms and associations between factors known in the acute phase and 100-day symptom persistence.

RESULTS

The most frequent post-acute symptoms were cough, loss of smell or taste and fatigue. At 100 days postinfection, 86 (8%) participants still experienced symptoms. Three post-acute COVID symptom clusters were identified: non-respiratory (headache and fatigue; 49% of participants with post-acute COVID symptoms); olfactory (15%) and respiratory (8%). Vaccination was associated with a lower risk of post-acute COVID symptoms 100 days after infection, although CIs were wide (OR: 0.5; 95% CI: 0.2 to 1.5), but not with non-respiratory symptoms (OR: 1.0; 95% CI: 0.3 to 4.4). Severe acute disease increased the risk of post-acute COVID symptoms (OR: 1.4; 95% CI: 1.2 to 1.5; per additional acute symptom).

CONCLUSIONS

In this cohort of infected community-dwelling app users, 5%-10% experienced post-acute COVID symptoms. The symptoms cluster in several distinct entities, which differ in incidence, patient characteristics and vaccination effects. This suggests multiple mechanisms underlying the development of post-acute COVID symptoms.

Novel Clinical, Immunological, and Metabolic Features Associated with Persistent Post-Acute COVID-19 Syndrome

The coronavirus disease 2019 (COVID-19) survivors are frequently observed to present persistent symptoms constituting what has been called "post-acute COVID-19 syndrome" (PACS) or "long COVID-19". Some clinical risk factors have been identified to be associated with PACS development; however, specific mechanisms responsible for PACS pathology remain unknown. This study investigates clinical, immunological, and metabolomic risk factors associated with post-acute COVID-19 syndrome (PACS) in 51 patients, assessed 7-19 months after acute infection. Among the participants, 62.7% were male and 37.2% were female, with an average age of 47.8 years. At the follow-up, 37.2% met the criteria for PACS, revealing significant differences in immunological and metabolomic profiles at the time of acute infection. Patients with PACS were characterized by elevated levels of mature low-density granulocytes (LDGs), interleukin-8 (IL-8), pyruvate, pseudouridine, and cystine. Baseline multivariate analysis showed increased pyruvate and decreased alpha tocopherol levels. At follow-up, there was a decrease in absolute B lymphocytes and an increase in non-classical monocytes and 3-hydroxyisovaleric acid levels. These findings suggest that specific immunological and metabolomic markers during acute infection can help identify patients at higher risk of developing persistent PACS.

Reduced autonomic function in patients with long-COVID-19 syndrome is mediated by cardiorespiratory fitness

BACKGROUND

Long-COVID-19 syndrome (LCS) exhibits neurological problems such as peripheral neuropathy and autonomic nervous system (ANS) dysfunction. Exercise intolerance and, consequently, low cardiorespiratory fitness (CRF) are some of the most common symptoms of LCS. We describe a series of individuals exhibiting LCS symptoms compared to a control group and posit that this condition may be related to the exercise capacity-mediated disruption of the ANS resulting particularly in exercise intolerance.

METHODS

This study included 87 individuals with LCS and 71 control participants without COVID-19 diagnoses. Heart rate variability (HRV) in supine position is commonly measured to diagnose autonomic dysregulation and subsequently analyzed using the Kubios software (Kuopio, Finland). CRF (peak VO2), post-COVID-19 patient-reported symptoms, maximal muscle strength (grip strength, bilateral leg press, leg extension, pectoral press, and back press exercises), and body composition were also measured. Analysis of covariance (ANCOVA) and mediation analysis were employed to assess the associations among LCS, peak VO2, and HRV indicators. Two-sided p < 0.05 was considered as significant.

RESULTS

The HRV parameters-RR interval, RMSSD, SDNN, PNS index, LF, HF, total power, SD1, and SD2-were significantly elevated (p < 0.05) in the control group when compared to the LCS patients. In contrast, the HR, stress index, and SNS index parameters were significantly higher (p < 0.05) in the LCS group. When adjusted for RR intervals, these parameters remained statistically significant (p < 0.05). A partially mediated effect was found between peak VO2 and RMSSD (mediation effect = 24.4%) as well as peak VO2 and SDNN (mediation effect = 25.1%) in the LCS patients.

CONCLUSIONS

These findings contribute new insights on the interplay between CRF and HRV indicators as well as endorse that dysautonomia may be related to the low peak VO2 observed in long COVID-19 patients.

Children with previous COVID-19 infection are more likely to present with recurrent acute otitis media or tube otorrhea

OBJECTIVE

Since December 2021, the number of children with COVID-19 infections has increased. Sequelae in children have not been well-described. Our goal was to determine if children with a history of COVID-19 infection (C19 group) were more likely to present with recurrent acute otitis media (rAOM) or post-ventilation tube otorrhea (VTO) than children who had no history of COVID-19 infection (NoC19 group).

METHODS

Charts of consecutive children presenting at a pediatric otolaryngology clinic from March-May 2022 were reviewed. Demographics, COVID-19 test history, comorbidities, ultimate diagnosis, physical exam findings, and management plan were included. No children had a known COVID-19 infection at the time of visit.

RESULTS

524 children were included, 228 (43.5 %) girls and 296 (56.5 %) boys. Mean age was 5 years (95 % CI 4.6-5.4). 115 (21.9 %) had a history of COVID-19 infection. 104 (19.8 %) had a diagnosis of rAOM or VTO, 26.1 % (30/115) children in C19 and 18.1 % (74/409) children in NoC19 (Fisher's Exact p = .04, OR = 1.6). For children without ventilation tubes in place, 23.5 % (27/115) in C19 had rAOM versus 15.2 % (62/409) in NoC19 (p = .03, OR = 1.7). 18.3 % (21/115) of the C19 group had nasal congestion compared to 6.6 % (27/409) of the NoC19 group (p < .001, OR = 3.2). There was no difference in incidence of otitis media with effusion, tonsil/adenoid hypertrophy, sleep-disordered breathing, or epistaxis between the groups.

CONCLUSION

Infection with COVID-19 may be associated with an increased risk of rAOM and VTO in children. This may affect healthcare utilization by increasing the need for pediatric and otolaryngologic care.

Autoantibodies in COVID-19 and Other Viral Diseases: Molecular, Cellular, and Clinical Perspectives

Autoantibodies are immune system-produced antibodies that wrongly target the body's cells and tissues for attack. The COVID-19 pandemic has made it possible to link autoantibodies to both the severity of pathogenic infection and the emergence of several autoimmune diseases after recovery from the infection. An overview of autoimmune disorders and the function of autoantibodies in COVID-19 and other infectious diseases are discussed in this review article. We also investigated the different categories of autoantibodies found in COVID-19 and other infectious diseases including the potential pathways by which they contribute to the severity of the illness. Additionally, it also highlights the probable connection between vaccine-induced autoantibodies and their adverse outcomes. The review also discusses the therapeutic perspectives of autoantibodies. This paper advances our knowledge about the intricate interaction between autoantibodies and COVID-19 by thoroughly assessing the most recent findings.

Long COVID: a clinical update

Post-COVID-19 condition (also known as long COVID) is generally defined as symptoms persisting for 3 months or more after acute COVID-19. Long COVID can affect multiple organ systems and lead to severe and protracted impairment of function as a result of organ damage. The burden of this disease, both on the individual and on health systems and national economies, is high. In this interdisciplinary Review, with a coauthor with lived experience of severe long COVID, we sought to bring together multiple streams of literature on the epidemiology, pathophysiology (including the hypothesised mechanisms of organ damage), lived experience and clinical manifestations, and clinical investigation and management of long COVID. Although current approaches to long COVID care are largely symptomatic and supportive, recent advances in clinical phenotyping, deep molecular profiling, and biomarker identification might herald a more mechanism-informed and personally tailored approach to clinical care. We also cover the organisation of services for long COVID, approaches to preventing long COVID, and suggestions for future research.

Excess risks of long COVID symptoms compared with identical symptoms in the general population: A systematic review and meta-analysis of studies with control groups

Background

It is important to understand the excess risks of symptoms of long COVID when compared to the same symptoms in the general population. We aimed to evaluate the association between coronavirus disease 2019 (COVID-19) infection and various long-term symptoms.

Methods

We conducted a systematic review and meta-analysis of studies measuring long COVID symptoms lasting for at least three months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in comparison to non-COVID-19 control groups. We searched MEDLINE and Embase (via Ovid), CINAHL (via EBSCOhost), the ProQuest Coronavirus Research Database, and the World Health Organization COVID-19 Research Database for relevant literature on 14 February 2023. The symptom list had 10 categories with 29 symptoms, including general, neurologic, respiratory, cardiac, dermatologic, eye, ear, musculoskeletal, psychiatric, and gastrointestinal symptoms. We performed random-effects meta-analysis and summarised the results using odds ratios (OR) and 95% confidence intervals (CI), after which we conducted subgroup analyses.

Results

We included 51 studies with 17 901 204 participants (range of mean age: 5.9-65.4 years; range of proportion of women: 11.2-96.0%). In the primary analysis, participants with COVID-19 had a significantly higher risk of having at least one long COVID symptom (OR = 2.032; 95% CI = 1.787-2.310). Specifically, they had higher risks of 25 symptoms, the highest of which were for smell (OR = 8.474; 95% CI = 6.357-11.295), taste (OR = 5.881; 95% CI = 3.818-9.059), post-exertional malaise (OR = 3.187; 95% CI = 2.602-3.904), shortness of breath (OR = 2.497; 95% CI = 2.125-2.935), brain fog (OR = 2.093; 95% CI = 1.362-3.218), hair loss (OR = 2.082; 95% CI = 1.291-3.358), chest pain (OR = 2.056; 95% CI = 1.692-2.498), cognitive decline (OR = 1.992; 95% CI = 1.560-2.544), palpitations (OR = 1.986; 95% CI = 1.647-2.395), and fatigue (OR = 1.971; 95% CI = 1.781-2.182). We found significant differences between studies with different follow-up times in cognitive decline, dizziness, palpitations, and sleep problems (P < 0.05). Adults had significantly higher risks of cognitive decline, hair loss, and joint pain than children (P < 0.05).

Conclusions

We found that COVID-19 can significantly increase the risk of many long COVID symptoms, without differences due to gender, age, or decrease over time after three months post-infection. This highlights that services and interventions for long COVID symptoms are needed.

Registration

PROSPERO (CRD42023409847).

Central Nervous System Histoplasmosis After Acute COVID-19 in An Adolescent

Central nervous system histoplasmosis is a serious complication of a common endemic mycosis, but it is rare in immunocompetent hosts. SARS-CoV-2 has introduced significant challenges into the healthcare setting with overlapping clinical presentations that may delay the diagnosis of alternative conditions. Additionally, it may lead to immune dysregulation and increase the risk for secondary infections, including invasive fungal diseases. Limited reports have described disseminated histoplasmosis in adults associated with COVID-19, but none have described central nervous system infection or complications in pediatric patients. We report a case of disseminated histoplasmosis involving the central nervous system in a previously healthy 13-year-old male with SARS-CoV-2 infection. An extensive immunological evaluation did not identify an underlying immunodeficiency. We highlight the potential of COVID-19 immune dys-regulation to contribute to the development or progression of invasive fungal disease. [Pediatr Ann. 2024;53(8):e305-e309.].

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

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

New-onset sarcoidosis in a patient with long COVID

Long COVID, often following SARS-CoV-2 infection, may stem from sustained inflammation, overlapping with autoimmune diseases like sarcoidosis. Though specific treatments lack, this link could shape future diagnostic and therapeutic methods.

COVID-19 and Long COVID: Disruption of the Neurovascular Unit, Blood-Brain Barrier, and Tight Junctions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), could affect brain structure and function. SARS-CoV-2 can enter the brain through different routes, including the olfactory, trigeminal, and vagus nerves, and through blood and immunocytes. SARS-CoV-2 may also enter the brain from the peripheral blood through a disrupted blood-brain barrier (BBB). The neurovascular unit in the brain, composed of neurons, astrocytes, endothelial cells, and pericytes, protects brain parenchyma by regulating the entry of substances from the blood. The endothelial cells, pericytes, and astrocytes highly express angiotensin converting enzyme 2 (ACE2), indicating that the BBB can be disturbed by SARS-CoV-2 and lead to derangements of tight junction and adherens junction proteins. This leads to increased BBB permeability, leakage of blood components, and movement of immune cells into the brain parenchyma. SARS-CoV-2 may also cross microvascular endothelial cells through an ACE2 receptor-associated pathway. The exact mechanism of BBB dysregulation in COVID-19/neuro-COVID is not clearly known, nor is the development of long COVID. Various blood biomarkers could indicate disease severity and neurologic complications in COVID-19 and help objectively diagnose those developing long COVID. This review highlights the importance of neurovascular and BBB disruption, as well as some potentially useful biomarkers in COVID-19, and long COVID/neuro-COVID.

Association of pulmonary function test abnormalities and quality-of-life measures after COVID-19 infection

BACKGROUND

Long-COVID is a multisystem disease that can lead to significant impairments in health-related quality of life (HRQoL). Following COVID-19 infection, abnormalities on pulmonary function tests (PFT) are common. The primary aim of this study is to evaluate for any correlation between PFT abnormalities and impairment in HRQoL scores following COVID-19 infection.

METHODS

This is an analysis of a prospective cohort of patients in Louisville, KY who were infected with COVID-19. Data collected included demographics, past medical history, laboratory tests, PFTs, and several HRQoL questionnaires such as the EuroQol 5 Dimension HRQoL questionnaire (EQ-5D-5 L), Generalized Anxiety Disorder 7 (GAD-7), Patient Health Questionnaire (PHQ-9), and Posttraumatic stress disorder checklist for DSM-5 (PCL-5). Descriptive statistics were performed, comparing PFTs (normal vs abnormal) and time since COVID-19 infection (3- vs 6- vs ≥ 12 months).

RESULTS

There were no significant differences in FEV1, FVC, or the percentage of patients with abnormal PFTs over time after COVID-19 infection. Following COVID-19, patients with normal PFTs had worse impairment in mobility HRQoL scores and change in GAD-7 scores over time. There were no differences over time in any of the HRQoL scores among patients with abnormal PFTs.

CONCLUSIONS

Among patients with an abnormal PFT, there was no temporal association with HRQoL scores as measured by EQ-5D-5 L, GAD-7, PHQ-9, and PCL-5. Among patients with a normal PFT, mobility impairment and anxiety may be associated with COVID-19 infection. Following COVID-19 infection, impairment in HRQoL scores is not completely explained by the presence of abnormalities on spirometry.

Epidemiological and clinical characteristics of long COVID-19 among Iranians: A community-based study in southern Iran

BACKGROUND

The study aimed to evaluate the prevalence and pattern of long COVID-19 (LC) symptoms among individuals who had contracted COVID-19, to calculate the incidence of LC, and to provide insights into risk factors associated with developing LC in this population.

METHODS

This population-based cross-sectional survey was conducted in Fars province in 2023. Adult participants with a history of COVID-19 were recruited using a cluster random sampling method, alongside a control group with similar characteristics through the same methodology. Data were collected through in-person interviews using two researcher-developed data collection forms focused on demographic and clinical information.

RESULTS

A total of 2010 participants, comprising 1561 (77.7%) and 449 (22.3%) individuals with and without a previous history of COVID-19 were included. Among those with COVID-19 history, the prevalence of experiencing any symptoms was 93.7% (95% CI of 92.3%-94.8%) during the disease acute phase and 36.4% (95% CI of 34.0%-38.8%) after recovery. The incidence of symptoms specifically related to COVID-19, calculated by comparing the symptom rates between participants with and without a history of COVID-19, was found to be 13%. Factors such as older age, previous hospitalization for COVID-19, presence of cardiovascular disease, and use of steroids/chemotherapy were associated with LC symptoms.

CONCLUSIONS

Our investigation sheds light on long-term aspects of COVID-19, demonstrating a significant prevalence of LC with diverse manifestations. It also underscores the importance of establishing standardized criteria and control groups in research on LC to address challenges related to heterogeneity and potential overestimation of symptoms.

Internal tremors and vibrations in long COVID: a cross-sectional study

BACKGROUND

Internal tremors and vibrations are symptoms previously described as part of neurologic disorders but not fully described as a part of long COVID. This study compared pre-pandemic comorbidities, new-onset conditions, and long COVID symptoms between people with internal tremors and vibrations as part of their long COVID symptoms and people with long COVID but without these symptoms.

METHODS

The Yale Listen to Immune, Symptom and Treatment Experiences Now (LISTEN) Study surveyed 423 adults who had long COVID between May 12, 2022 and June 1, 2023. The exposure variable was long COVID symptoms of internal tremors and vibrations. The outcome variables were demographic characteristics, pre-pandemic comorbidities, new-onset conditions, other symptoms, and quality of life.

RESULTS

Among study participants with long COVID, median age was 46 years [IQR, 38-56]), 74% were female, 87% were Non-Hispanic White, and 158 (37%) reported "internal tremors, or buzzing/vibration" as a long COVID symptom. The 2 groups reported similar pre-pandemic comorbidities, but people with internal tremors reported worse health as measured by the Euro-QoL visual analogue scale (median: 40 points [IQR, 30-60] vs. 50 points [IQR, 35-62], P = 0.007) and had higher rates of new-onset mast cell disorders (11% [95% CI, 7.1-18] vs. 2.6% [1.2-5.6], P = 0.008) and neurologic conditions (22% [95% CI, 16-29] vs. 8.3% [5.4-12], P = 0.004).

CONCLUSIONS

Among people with long COVID, those with internal tremors and vibrations had different conditions and symptoms and worse health status compared with others who had long COVID without these symptoms.

Clinical characteristics, anti-SARS-CoV-2 IgG titers, and inflammatory markers in individuals with post-COVID-19 condition in Kenya: a cross-sectional study

Background

Post-coronavirus disease 2019 (post-COVID-19) is associated with considerable morbidity and reduced quality of life. However, studies characterizing the post-COVID-19 condition in Kenya are limited. This study aimed to determine the prevalence of post-COVID-19 condition and determine the clinical characteristics, anti-SARS-CoV-2 IgG titers, and concentrations of inflammatory markers of individuals with post-COVID-19 condition in Kenya.

Methods

This descriptive cross-sectional study was conducted at the Kenyatta University Health Unit, Kenya. Demographic and clinical data were collected using a questionnaire. The serum levels of anti-SARS-CoV-2 antibodies, interleukin 6 (IL-6), and C-reactive protein (CRP) were quantified by enzyme-linked immunosorbent assays. Independent samples t-test was used to compare the anti-SARS-CoV-2 IgG, IL-6, and CRP levels between the participants with and without post-COVID-19 symptoms. The case definition for post-COVID-19 condition was persistence of acute COVID-19 symptoms or emergence of new symptoms 3 months after COVID-19 diagnosis, symptoms lasting for ≥2 months, and absence of any other etiological basis to explain the symptoms.

Results

A total of 189 volunteers were recruited in this study (median age: 21 years, range: 18-71 years; male, 49.2%). Forty participants reported having had at least one COVID-19 positive diagnosis in the past, of which 12 (30%) complained of post-COVID-19 symptoms. Significant differences in the number and duration of symptoms were observed between the individuals with and without post-COVID-19 symptoms (t-statistic = 2.87, p = 0.01; t-statistic = 2.39, p = 0.02, respectively). However, no significant differences in serum levels of anti-SARS-CoV-2 IgG, IL-6, and CRP were observed between the two groups (P = 0.08, 0.9, and 0.28, respectively).

Conclusion

These findings suggest that post-COVID-19 condition is a health concern even for a relatively young population in Kenya and globally. This condition requires more attention and well-designed studies to better define it and identify clinical chemistry markers that can be used for its diagnosis.

Exploring Symptom Overlaps: Post-COVID-19 Neurological Syndrome and Post-Concussion Syndrome in Athletes

The COVID-19 pandemic has introduced new challenges in managing neurological conditions, particularly among athletes. This paper explores the intersection of post-COVID-19 neurological syndrome (PCNS/PASC) and post-concussion syndrome (PCS), focusing on their implications in sports medicine. Our analysis covers the symptomatology, pathophysiology, and management strategies for PCNS/PASC and PPCS, with special attention paid to the unique challenges faced by athletes recovering from these conditions, including the risk of symptom exacerbation and prolonged recovery. Key findings reveal that both PCNS/PASC and PPCS present with overlapping symptoms such as cognitive difficulties, exercise intolerance, and mental health issues, but differ in specific manifestations like anosmia and ageusia, unique to COVID-19. Pathophysiological analysis reveals similarities in blood-brain barrier disruption (BBB) but differences in the extent of immune activation. Management strategies emphasize a gradual increase in physical activity, close symptom monitoring, and psychological support, with a tailored approach for athletes. Specific interventions include progressive aerobic exercises, resistance training, and cognitive rehabilitation. Furthermore, our study highlights the importance of integrating neurology, psychiatry, physical therapy, and sports medicine to develop comprehensive care strategies. Our findings underscore the dual challenge of COVID-19 and concussion in athletes, necessitating a nuanced, interdisciplinary approach to effective management. Future research should focus on the long-term neurological effects of both conditions and optimizing treatment protocols to improve patient outcomes. This comprehensive understanding is crucial for advancing the management of athletes affected by these overlapping conditions and ensuring their safe return to sports.

Long COVID Definitions and Models of Care : A Scoping Review

BACKGROUND

Definitions of long COVID are evolving, and optimal models of care are uncertain.

PURPOSE

To perform a scoping review on definitions of long COVID and provide an overview of care models, including a proposed framework to describe and distinguish models.

DATA SOURCES

English-language articles from Ovid MEDLINE, PsycINFO, the Cochrane Library, SocINDEX, Scopus, Embase, and CINAHL published between January 2021 and November 2023; gray literature; and discussions with 18 key informants.

STUDY SELECTION

Publications describing long COVID definitions or models of care, supplemented by models described by key informants.

DATA EXTRACTION

Data were extracted by one reviewer and verified for accuracy by another reviewer.

DATA SYNTHESIS

Of 1960 screened citations, 38 were included. Five clinical definitions of long COVID varied with regard to timing since symptom onset and the minimum duration required for diagnosis; 1 additional definition was symptom score-based. Forty-nine long COVID care models were informed by 5 key principles: a core "lead" team, multidisciplinary expertise, comprehensive access to diagnostic and therapeutic services, a patient-centered approach, and providing capacity to meet demand. Seven characteristics provided a framework for distinguishing models: home department or clinical setting, clinical lead, collocation of other specialties, primary care role, population managed, use of teleservices, and whether the model was practice- or systems-based. Using this framework, 10 representative practice-based and 3 systems-based models of care were identified.

LIMITATIONS

Published literature often lacked key model details, data were insufficient to assess model outcomes, and there was overlap between and variability within models.

CONCLUSION

Definitions of long COVID and care models are evolving. Research is needed to optimize models and evaluate outcomes of different models.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (Protocol posted at https://effectivehealthcare.ahrq.gov/products/long-covid-models-care/protocol.).

Association of psychiatric disorders with clinical diagnosis of long COVID in US veterans

BACKGROUND

Psychiatric disorders may be a risk factor for long COVID, broadly defined as COVID-19 conditions continuing three months post-acute infection. In US Veterans with high psychiatric burden, we examined associations between psychiatric disorders and clinical diagnosis of long COVID.

METHODS

We conducted a retrospective cohort study using health records from VA patients with a positive SARS-CoV-2 test from February 2020 to February 2023. Generalized linear models estimated associations between any psychiatric disorder and likelihood of subsequent diagnosis with long COVID (i.e. two or more long COVID clinical codes). Models were adjusted for socio-demographic, medical, and behavioral factors. Secondary models examined individual psychiatric disorders and age-stratified associations.

RESULTS

Among 660 217 VA patients with positive SARS-CoV-2 tests, 56.3% had at least one psychiatric disorder diagnosis and 1.4% were diagnosed with long COVID. Individuals with any psychiatric disorder had higher risk for long COVID diagnosis in models adjusted for socio-demographic factors, vaccination status, smoking, and medical comorbidities (relative risk, RR = 1.28, 95% CI 1.21-1.35), with the strongest associations in younger individuals. Considering specific disorders, depressive, anxiety, and stress-related disorders were associated with increased risk for long COVID diagnoses (RRs = 1.36-1.48), but associations were in the opposite direction for substance use and psychotic disorders (RRs = 0.78-0.88).

CONCLUSIONS

Psychiatric disorder diagnoses were associated with increased long COVID diagnosis risk in VA patients, with the strongest associations observed in younger individuals. Improved surveillance, treatment, and prevention for COVID-19 and its long-term sequelae should be considered for individuals with psychiatric conditions.

Post-COVID conditions response: a collaborative approach to -establishing multidisciplinary clinics in Ecuador

INTRODUCTION

Worldwide, 3.7% (144.7 million) of people diagnosed with COVID-19 developed Post-COVID Conditions (PCC). Therefore, creating and implementing multidisciplinary rehabilitation clinics is important to address the needs of patients and improve overall recovery. This study was made possible with support from the United States Agency for International Development funded RISE program, under the terms of the cooperative agreement 7200AA19CA00003.

METHODS

This case study was conducted in Ecuador and describes the creation and implementation of 21 PCC rehabilitation clinics in primary healthcare centers and secondary level hospitals in 7 provinces across the country. Data was gathered for the identification of partnering health facilities and needs, for the evaluation of knowledge enhancement in health professionals after a specific training program, and for the measurement of key performance indicators. This article emphasizes the organization, educational strategies, and implementation of rehabilitation programs tailored specifically for the management of Post-COVID Conditions in Ecuador.

RESULTS

The implementation of PCC rehabilitation clinics involved a collaborative effort between the Ministry of Public Health (MOPH), the private sector and a non-governmental organization (Jhpiego). Twenty-one health facilities from the primary and secondary level of care were selected, and PCC rehabilitation implemented in 7 provinces of Ecuador. Additionally, 133 health providers were trained and a total of 13,846 patients treated, among whom 859 had a diagnosis of PCC. Medical doctors outperformed nurses in both pre- and post-tests scores. However, all healthcare professionals demonstrated comparable improvement in knowledge acquisition. Rehabilitation manuals were developed and adopted by the MOPH, rehabilitation equipment was donated and a mobile application, "RESPIRA", was developed and disseminated free of charge.

CONCLUSION

The establishment of PCC rehabilitation clinics in Ecuador was successful in identifying patients in need of early rehabilitation. The insights of this study can serve as a guide for the development of similar initiatives in other countries. Tailored courses are essential to address disparities and ensure comprehensive skill development and promote equitable healthcare delivery.

Escalated complement activation during hospitalization is associated with higher risk of 60-day mortality in SARS-CoV-2-infected patients

BACKGROUND

The complement system, an upstream recognition system of innate immunity, is activated upon SARS-CoV-2 infection. To gain a deeper understanding of the extent and duration of this activation, we investigated complement activation profiles during the acute phase of COVID-19, its persistence post-recovery and dynamic changes in relation to disease severity.

METHODS

Serial blood samples were obtained from two cohorts of hospitalized COVID-19 patients (n = 457). Systemic complement activation products reflecting classical/lectin (C4d), alternative (C3bBbP), common (C3bc) and terminal pathway (TCC and C5a) were measured during hospitalization (admission, days 3-5 and days 7-10), at 3 months and after 1 year. Levels of activation and temporal profiles during hospitalization were related to disease severity defined as respiratory failure (PO2/FiO2 ratio <26.6 kPa) and/or admission to intensive care unit, 60-day total mortality and pulmonary pathology after 3 months.

FINDINGS

During hospitalization, TCC, C4d, C3bc, C3bBbP and C5a were significantly elevated compared to healthy controls. Severely ill patients had significantly higher levels of TCC and C4d (p < 0.001), compared to patients with moderate COVID-19. Escalated levels of TCC and C4d during hospitalization were associated with a higher risk of 60-day mortality (p < 0.001), and C4d levels were additionally associated with chest CT changes at 3 months (p < 0.001). At 3 months and 1 year, we observed consistently elevated levels of most complement activation products compared to controls.

CONCLUSION

Hospitalized COVID-19 patients display prominent and long-lasting systemic complement activation. Optimal targeting of the system may be achieved through enhanced risk stratification and closer monitoring of in-hospital changes of complement activation products.

Cohort profile: the Johns Hopkins COVID Long Study (JHCLS)-a US nationwide prospective cohort study

PURPOSE

COVID-19 continues to affect millions of individuals worldwide, both in the short and long term. The post-acute complications of SARS-CoV-2 infection, referred to as long COVID, result in diverse symptoms affecting multiple organ systems. Little is known regarding how the symptoms associated with long COVID progress and resolve over time. The Johns Hopkins COVID Long Study aims to prospectively examine the short-term and long-term consequences of COVID-19 in individuals both with and without a history of SARS-CoV-2 infection using self-reported data collected in an online survey.

PARTICIPANTS

16 764 adults with a history of SARS-CoV-2 infection and 799 adults without a history of SARS-CoV-2 infection who completed an online baseline survey.

FINDINGS TO DATE

This cohort profile describes the baseline characteristics of the Johns Hopkins COVID Long Study. Among 16 764 participants with a history of SARS-CoV-2 infection and defined long COVID status, 75% reported a very good or excellent health status prior to infection, 99% reported experiencing at least one COVID-19 symptom during the acute phase of infection, 9.9% reported hospitalisation and 63% were defined as having long COVID using the WHO definition.

FUTURE PLANS

Analysis of longitudinal data will be used to investigate the progression and resolution of long COVID symptoms over time.

Effects of Pycnogenol® in people with post-COVID-19 condition (PYCNOVID): study protocol for a single-center, placebo controlled, quadruple-blind, randomized trial

BACKGROUND

A significant proportion of the global population has been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at some point since the onset of the pandemic. Although most individuals who develop coronavirus disease 2019 (COVID-19) recover without complications, about 6% have persistent symptoms, referred to as post-COVID-19 condition (PCC). Intervention studies investigating treatments that potentially alleviate PCC-related symptoms and thus aim to mitigate the global public health burden and healthcare costs linked to PCC are desperately needed. The PYCNOVID trial investigates the effects of Pycnogenol®, a French maritime pine bark extract with anti-inflammatory and antioxidative properties, versus placebo on patient-reported health status in people with PCC.

METHODS

This is a single-center, placebo-controlled, quadruple blind, randomized trial. We aim to randomly assign 150 individuals with PCC (1:1 ratio) to receive either 200 mg Pycnogenol® or placebo daily for 12 weeks. Randomization is stratified for duration of PCC symptoms (≤ 6 months versus > 6 months) and presence of symptomatic chronic disease(s). The primary endpoint is perceived health status at 12 weeks (EuroQol-Visual Analogue Scale) adjusted for baseline values and stratification factors. Secondary endpoints include change in self-reported PCC symptoms, health-related quality of life, symptoms of depression and anxiety, cognitive function, functional exercise capacity, physical activity measured with accelerometry, and blood biomarkers for endothelial health, inflammation, coagulation, platelet function, and oxidative stress. Investigators, study participants, outcome assessors, and data analysts are blinded regarding the intervention assignment. Individuals with PCC were involved in the design of this study.

DISCUSSION

This is the first trial to investigate the effects of Pycnogenol® versus placebo on patient-reported health status in people with PCC. Should the trial proof clinical effectiveness, Pycnogenol® may serve as a therapeutic approach to mitigate symptoms associated with PCC.

TRIAL REGISTRATION

The study is registered at ClinicalTrials.gov. :NCT05890534, June 6, 2023.

Long COVID management: a mini review of current recommendations and underutilized modalities

Long COVID is a condition that develops in a subset of patients after COVID-19 infection comprising of symptoms of varying severity encompassing multiple organ systems. Currently, long COVID is without consensus on a formal definition, identifiable biomarkers, and validated treatment. Long COVID is expected to be a long-term chronic condition for a subset of patients and is associated with suffering and incapacity. There is an urgent need for clear management guidelines for the primary care provider, who is essential in bridging the gap with more specialized care to improve quality of life and functionality in their patients living with long COVID. The purpose of this mini review is to provide primary care providers with the latest highlights from existing literature regarding the most common long COVID symptoms and current management recommendations. This review also highlights the underutilized interventions of stellate ganglion blocks and low-dose naltrexone, both with well-established safety profiles demonstrated to improve quality of life and functionality for patients suffering with some symptoms of long COVID, and encourages prompt referral to interventional pain management.

Exploring the Pathophysiology of Long COVID: The Central Role of Low-Grade Inflammation and Multisystem Involvement

Long COVID (LC), also referred to as Post COVID-19 Condition, Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), and other terms, represents a complex multisystem disease persisting after the acute phase of COVID-19. Characterized by a myriad of symptoms across different organ systems, LC presents significant diagnostic and management challenges. Central to the disorder is the role of low-grade inflammation, a non-classical inflammatory response that contributes to the chronicity and diversity of symptoms observed. This review explores the pathophysiological underpinnings of LC, emphasizing the importance of low-grade inflammation as a core component. By delineating the pathogenetic relationships and clinical manifestations of LC, this article highlights the necessity for an integrated approach that employs both personalized medicine and standardized protocols aimed at mitigating long-term consequences. The insights gained not only enhance our understanding of LC but also inform the development of therapeutic strategies that could be applicable to other chronic conditions with similar pathophysiological features.

Excess burden of respiratory and abdominal conditions following COVID-19 infections during the ancestral and Delta variant periods in the United States: An EHR-based cohort study from the RECOVER program

IMPORTANCE

The frequency and characteristics of post-acute sequelae of SARS-CoV-2 infection (PASC) may vary by SARS-CoV-2 variant.

OBJECTIVE

To characterize PASC-related conditions among individuals likely infected by the ancestral strain in 2020 and individuals likely infected by the Delta variant in 2021.

DESIGN

Retrospective cohort study of electronic medical record data for approximately 27 million patients from March 1, 2020-November 30, 2021.

SETTING

Healthcare facilities in New York and Florida.

PARTICIPANTS

Patients who were at least 20 years old and had diagnosis codes that included at least one SARS-CoV-2 viral test during the study period.

EXPOSURE

Laboratory-confirmed COVID-19 infection, classified by the most common variant prevalent in those regions at the time.

MAIN OUTCOME(S) AND MEASURE(S)

Relative risk (estimated by adjusted hazard ratio [aHR]) and absolute risk difference (estimated by adjusted excess burden) of new conditions, defined as new documentation of symptoms or diagnoses, in persons between 31-180 days after a positive COVID-19 test compared to persons without a COVID-19 test or diagnosis during the 31-180 days after the last negative test.

RESULTS

We analyzed data from 560,752 patients. The median age was 57 years; 60.3% were female, 20.0% non-Hispanic Black, and 19.6% Hispanic. During the study period, 57,616 patients had a positive SARS-CoV-2 test; 503,136 did not. For infections during the ancestral strain period, pulmonary fibrosis, edema (excess fluid), and inflammation had the largest aHR, comparing those with a positive test to those without a COVID-19 test or diagnosis (aHR 2.32 [95% CI 2.09 2.57]), and dyspnea (shortness of breath) carried the largest excess burden (47.6 more cases per 1,000 persons). For infections during the Delta period, pulmonary embolism had the largest aHR comparing those with a positive test to a negative test (aHR 2.18 [95% CI 1.57, 3.01]), and abdominal pain carried the largest excess burden (85.3 more cases per 1,000 persons).

CONCLUSIONS AND RELEVANCE

We documented a substantial relative risk of pulmonary embolism and a large absolute risk difference of abdomen-related symptoms after SARS-CoV-2 infection during the Delta variant period. As new SARS-CoV-2 variants emerge, researchers and clinicians should monitor patients for changing symptoms and conditions that develop after infection.

mRNA vaccines protect from the lung microvasculature injury and the capillary blood volume loss occurring in SARS-CoV-2 paucisymptomatic infections

INTRODUCTION

The reduction of lung capillary blood volume (Vc) had been identified as the microvascular injury mostly underlying the respiratory Long-COVID syndrome following post-COVID-19 pneumonia. The same kind of injury have been recently also found in several individuals after milder paucisymptomatic SARS-CoV-2 infections. Though current guidelines strongly recommend vac-cination, studies aimed to investigate the in vivo protection of anti-SARS-CoV-2 vaccines on lung microvascular targets still are missing to our best knowledge.

AIM

to assess the protection of mRNA vaccines from the reduction of lung capillary blood volume (Vc) caused by pauci-symptomatic SARS.CoV-2 infections in vaccinated compared to unvaccinated individuals.

METHODS

Non-smoking individuals with recent paucisymptomatic SARS-CoV-2 infection were divided into vaccinated and unvaccinated groups. Lung function parameters, including single-breath diffusing capacity and microvascular blood volume, were compared between groups.

RESULTS

fifty vaccinated and twenty-five unvaccinated well-matched individuals were studied. Differently than usual lung function parameters, only the single-breath simultaneous assessment of sDLCO, sDLNO/sDLCO ratio and Vc allowed to identify the occurrence of the lung microvascular injury with high sensitivity and specificity (p<0.001).

CONCLUSION

mRNA vaccines proved to exert a high protection from the loss of lung capillary blood volume (Vc) induced by SARS.CoV-2 paucisymptomatic infections (p<0.001). The availability of this non-invasive investigational model should be regarded as a very helpful tool for assessing and comparing in vivo the protective effect of mRNA vaccines on the human microvascular structures of the deep lung.

Genetic Polymorphisms of P2RX7 but Not of ADORA2A Are Associated with the Severity of SARS-CoV-2 Infection

SARS-CoV-2 infection ranges from mild to severe presentations, according to the intensity of the aberrant inflammatory response. Purinergic receptors dually control the inflammatory response: while adenosine A2A receptors (A2ARs) are anti-inflammatory, ATP P2X7 receptors (P2X7Rs) exert pro-inflammatory effects. The aim of this study was to assess if there were differences in allelic and genotypic frequencies of a loss-of-function SNP of ADORA2A (rs2298383) and a gain-of-function single nucleotide polymorphism (SNP) of P2RX7 (rs208294) in the severity of SARS-CoV-2-associated infection. Fifty-five individuals were enrolled and categorized according to the severity of the infection. Endpoint genotyping was performed in blood cells to screen for both SNPs. The TT genotype (vs. CT + CC) and the T allele (vs. C allele) of P2RX7 SNP were found to be associated with more severe forms of COVID-19, whereas the association between ADORA2A SNP and the severity of infection was not significantly different. The T allele of P2RX7 SNP was more frequent in people with more than one comorbidity and with cardiovascular conditions and was associated with colorectal cancer. Our findings suggest a more prominent role of P2X7R rather than of A2AR polymorphisms in SARS-CoV-2 infection, although larger population-based studies should be performed to validate our conclusions.

What Role Does Microthrombosis Play in Long COVID?

Soon after the outbreak of coronavirus disease 2019 (COVID-19), unexplained sustained fatigue, cognitive disturbance, and muscle ache/weakness were reported in patients who had recovered from acute COVID-19 infection. This abnormal condition has been recognized as "long COVID (postacute sequelae of COVID-19 [PASC])" with a prevalence estimated to be from 10 to 20% of convalescent patients. Although the pathophysiology of PASC has been studied, the exact mechanism remains obscure. Microclots in circulation can represent one of the possible causes of PASC. Although hypercoagulability and thrombosis are critical mechanisms of acute COVID-19, recent studies have reported that thromboinflammation continues in some patients, even after the virus has cleared. Viral spike proteins and RNA can be detected months after patients have recovered, findings that may be responsible for persistent thromboinflammation and the development of microclots. Despite this theory, long-term results of anticoagulation, antiplatelet therapy, and vascular endothelial protection are inconsistent, and could not always show beneficial treatment effects. In summary, PASC reflects a heterogeneous condition, and microclots cannot explain all the presenting symptoms. After clarification of the pathomechanisms of each symptom, a symptom- or biomarker-based stratified approach should be considered for future studies.

Can inflammatory plasma proteins predict Long COVID or Fatigue severity after SARS-CoV-2 infection?

OBJECTIVE

To investigate whether specific immune response plasma proteins can predict an elevated risk of developing Long COVID symptoms or fatigue severity after SARS-CoV-2 infection.

METHODS

This study was based on 257 outpatients with test-confirmed SARS-CoV-2 infection between February 2020 and January 2021. At least 12 weeks after the acute infection, 92 plasma proteins were measured using the Olink Target 96 immune response panel (median time between acute infection and venous blood sampling was 38.8 [IQR: 24.0-48.0] weeks). The presence of Long COVID symptoms and fatigue severity was assessed 115.8 [92.5-118.6] weeks after the acute infection by a follow-up postal survey. Long COVID (yes/no) was defined as having one or more of the following symptoms: fatigue, shortness of breath, concentration or memory problems. The severity of fatigue was assessed using the Fatigue Assessment Scale (FAS). In multivariable-adjusted logistic and linear regression models the associations between each plasma protein (exposure) and Long COVID (yes/no) or severity of fatigue were investigated.

RESULTS

Nine plasma proteins were significantly associated with Long COVID before, but not after adjusting for multiple testing (FDR-adjustment): DFFA, TRIM5, TRIM21, HEXIM1, SRPK2, PRDX5, PIK3AP1, IFNLR1 and HCLS1. Moreover, a total of 10 proteins were significantly associated with severity of fatigue before FDR-adjustment: SRPK2, ITGA6, CLEC4G, HEXIM1, PPP1R9B, PLXNA4, PRDX5, DAPP1, STC1 and HCLS1. Only SRPK2 and ITGA6 remained significantly associated after FDR-adjustment.

CONCLUSIONS

This study demonstrates that certain immune response plasma proteins might play an important role in the pathophysiology of Long COVID and severity of fatigue after SARS-CoV-2 infection.

Hyperaemia during dynamic handgrip exercise is preserved in healthy young subjects after recovery from COVID-19

We sought to investigate possible impaired hyperaemia during dynamic handgrip exercise (HGE) in young healthy individuals who had recovered from COVID-19. We tested the vascular function in individuals recovered from COVID-19 using a nitric oxide donor (i.e., sodium nitroprusside; SNP), which could revert a possible impaired endothelial function during HGE. Further, we tested whether individuals who recovered from COVID-19 would present exaggerated brachial vascular resistance under an adrenergic agonist (i.e., phenylephrine; PHE) stimuli during HGE. Participants were distributed into two groups: healthy controls (Control; men: n = 6, 30 ± 3 years, 26 ± 1 kg/m2; and women: n = 5, 25 ± 1 years, 25 ± 1 kg/m2) and subjects recovered from COVID-19 (post-COVID; men: n = 6, 29 ± 3 years, 25 ± 1 kg/m2; and women: n = 10, 32 ± 4 years, 22 ± 1 kg/m2). Participants in the post-COVID group tested positive (RT-PCR) 12-14 weeks before the protocol. Heart rate (HR), brachial blood pressure (BP), brachial blood flow (BBF) and vascular conductance (BVC) at rest were not different between groups. The HGE increased HR (Control: Δ9 ± 0.4 bpm; and post-COVID: Δ11 ± 0.4 bpm) and BP (Control: Δ6 ± 1 mmHg; and post-COVID: Δ12 ± 0.6 mmHg) in both groups. Likewise, BBF (Control: Δ632 ± 38 ml/min; and post-COVID: Δ620 ± 27 ml/min) and BVC (Control: Δ6.6 ± 0.4 ml/min/mmHg; and post-COVID: Δ6.1 ± 0.3 ml/min/mmHg) increased during HGE. SNP did not change HGE-induced hyperaemia but did decrease BP, which induced a reflex-related increase in HR. PHE infusion also did not change the HGE-induced hyperaemia but raised BP and reduced HR. In conclusion, exercise-induced hyperaemia is preserved in healthy young subjects 12-14 weeks after recovery from COVID-19 infection.

Post-COVID Trajectory of Pentraxin 3 Plasma Levels Over 6 Months and Their Association with the Risk of Developing Post-Acute Depression and Anxiety

BACKGROUND AND OBJECTIVES

Clinical manifestations of coronavirus disease 2019 (COVID-19) often persist after acute disease resolution. Underlying molecular mechanisms are unclear. The objective of this original article was to longitudinally measure plasma levels of markers of the innate immune response to investigate whether they associate with and predict post-COVID symptomatology.

METHODS

Adult patients with previous severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during the first pandemic wave who underwent the 6-month multidisciplinary follow-up were included. Plasma levels of pentraxin 3 (PTX3), the complement components C3a and C5a, and chitinase-3 like-protein-1 (CHI3L1) were measured at hospital admission during acute disease (baseline) and at 1 and 6 months after hospital discharge. Associations with post-COVID-19 sequelae at 6 months were investigated using descriptive statistic and multiple regression models.

RESULTS

Ninety-four COVID-19 patients were included. Baseline PTX3, C5a, C3a, and CHI3L1 did not predict post-COVID-19 sequelae. The extent of the reduction of PTX3 over time (delta PTX3) was associated with lower depressive and anxiety symptoms at 6 months (both p < 0.05). When entering sex, age, need for intensive care unit or non-invasive ventilation during hospital stay, psychiatric history, and baseline PTX3 as nuisance covariates into a generalized linear model (GLM), the difference between baseline and 6-month PTX3 levels (delta PTX3) significantly predicted depression (χ2 = 4.66, p = 0.031) and anxiety (χ2 = 4.68, p = 0.031) at 6 months. No differences in PTX3 levels or PTX3 delta were found in patients with or without persistent or new-onset other COVID-19 symptoms or signs at 6 months. Plasma levels of C3a, C5a, and CHI3L1 did not correlate with PTX3 levels at either time point and failed to associate with residual or de novo respiratory or systemic clinical manifestations of the disease at 6 months.

CONCLUSIONS

A lower reduction of plasma PTX3 after acute COVID-19 associates with the presence of depression and anxiety, suggesting an involvement of inflammation in post-COVID-19 psychopathology and a potential role of PTX3 as a biomarker.

Novel ultrasound-guided supraclavicular stellate ganglion block

INTRODUCTION

Stellate ganglion block (SGB) provides diagnostic and therapeutic benefits in pain syndromes in the head, neck, and upper extremity, including complex regional pain syndrome Types I and II, Raynaud's disease, hyperhidrosis, arterial embolism in the region of the arm.

METHODS

We present a novel ultrasound-guided supraclavicular stellate ganglion block. Considering the existing anatomical structures of the targeted area.

RESULTS AND CONCLUSIONS

We hope that we can provide fewer complications and additional benefits with this new approach.

Hemoglobin and Its Relationship with Fatigue in Long-COVID Patients Three to Six Months after SARS-CoV-2 Infection

Background: While some long-term effects of COVID-19 are respiratory in nature, a non-respiratory effect gaining attention has been a decline in hemoglobin, potentially mediated by inflammatory processes. In this study, we examined the correlations between hemoglobin levels and inflammatory biomarkers and evaluated the association between hemoglobin and fatigue in a cohort of Long-COVID patients. Methods: This prospective cohort study in the Netherlands evaluated 95 (mostly hospitalized) patients, aged 40-65 years, 3-6 months post SARS-CoV-2 infection, examining their venous hemoglobin concentration, anemia (hemoglobin < 7.5 mmol/L in women and <8.5 mmol/L in men), inflammatory blood biomarkers, average FSS (Fatigue Severity Score), demographics, and clinical features. Follow-up hemoglobin was compared against hemoglobin during acute infection. Spearman correlation was used for assessing the relationship between hemoglobin concentrations and inflammatory biomarkers, and the association between hemoglobin and fatigue was examined using logistic regression. Results: In total, 11 (16.4%) participants were suffering from anemia 3-6 months after SARS-CoV-2 infection. The mean hemoglobin value increased by 0.3 mmol/L 3-6 months after infection compared to the hemoglobin during the acute phase (p-value = 0.003). Whilst logistic regression showed that a 1 mmol/L greater increase in hemoglobin is related to a decrease in experiencing fatigue in Long-COVID patients (adjusted OR 0.38 [95%CI 0.13-1.09]), we observed no correlations between hemoglobin and any of the inflammatory biomarkers examined. Conclusion: Our results indicate that hemoglobin impairment might play a role in developing Long-COVID fatigue. Further investigation is necessary to identify the precise mechanism causing hemoglobin alteration in these patients.

Does sex modify the effect of pre-pandemic body mass index on the risk of Long COVID? Evidence from the longitudinal analysis of the Survey of Health, Ageing and Retirement in Europe

BACKGROUND

Research on Long COVID risk factors is ongoing. High body mass index (BMI) may increase Long COVID risk, yet no evidence has been established regarding sex differences in the relationship between BMI and the risk of Long COVID. Investigating the nature of this relationship was the main objective of this study.

METHODS

A population-based prospective study involving a sample of respondents aged 50 years and older (n = 4004) from 27 European countries that participated in the 2020 and 2021 Survey of Health, Ageing and Retirement in Europe's (SHARE) Corona Surveys and in Waves 7 and 8 of the main SHARE survey. Logistic regression models were estimated to produce unadjusted and adjusted estimates of the sex differences in the relationship between BMI and Long COVID.

RESULTS

Linear relationship for females, with probability of Long COVID increasing with BMI (68% at BMI = 18, 93% at BMI = 45). Non-linear relationship for males, with probability of Long COVID of 27% at BMI = 18, 68% at BMI = 33, and 40% at BMI = 45. Relationships remained significant after adjusting for known Long COVID risk factors (age and COVID-19 hospitalization), presence of chronic diseases, and respondents' place of residence.

CONCLUSION

Sex differences appear to play an important role in the relationship between BMI and risk of Long COVID. Overall, females were more likely to have Long COVID, regardless of their BMI. Males at the higher end of the BMI spectrum had a lower risk of Long COVID as opposed to their female counterparts. Sex-specific research is recommended for better understanding of Long COVID risk factors.

Effects of sEH inhibition on the eicosanoid and cytokine storms in SARS-CoV-2-infected mice

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection involves an initial viral infection phase followed by a host-response phase that includes an eicosanoid and cytokine storm, lung inflammation and respiratory failure. While vaccination and early anti-viral therapies are effective in preventing or limiting the pathogenic host response, this latter phase is poorly understood with no highly effective treatment options. Inhibitors of soluble epoxide hydrolase (sEH) increase levels of anti-inflammatory molecules called epoxyeicosatrienoic acids (EETs). This study aimed to investigate the impact of sEH inhibition on the host response to SARS-CoV-2 infection in a mouse model with human angiotensin-converting enzyme 2 (ACE2) expression. Mice were infected with SARS-CoV-2 and treated with either vehicle or the sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU). At day 5 post-infection, SARS-CoV-2 induced weight loss, clinical signs, a cytokine storm, an eicosanoid storm, and severe lung inflammation with ~50% mortality on days 6-8 post-infection. SARS-CoV-2 infection induced lung expression of phospholipase A2 (PLA2), cyclooxygenase (COX) and lipoxygenase (LOX) pathway genes, while suppressing expression of most cytochrome P450 genes. Treatment with the sEH inhibitor TPPU delayed weight loss but did not alter clinical signs, lung cytokine expression or overall survival of infected mice. Interestingly, TPPU treatment significantly reversed the eicosanoid storm and attenuated viral-induced elevation of 39 fatty acids and oxylipins from COX, LOX and P450 pathways, which suggests the effects at the level of PLA2 activation. The suppression of the eicosanoid storm by TPPU without corresponding changes in lung cytokines, lung inflammation or mortality reveals a surprising dissociation between systemic oxylipin and cytokine signaling pathways during SARS-CoV-2 infection and suggests that the cytokine storm is primarily responsible for morbidity and mortality in this animal model.

Presence of SARS-CoV-2 RNA in COVID-19 survivors with post-COVID symptoms: a systematic review of the literature

INTRODUCTION

Viral persistence is one of the main hypotheses explaining the presence of post-COVID symptoms. This systematic review investigated the presence of SARS-CoV-2 RNA in plasma, stool, urine, and nasal/oral swab samples in individuals with post-COVID symptomatology.

CONTENT

MEDLINE, CINAHL, PubMed, EMBASE, Web of Science databases, as well as medRxiv/bioRxiv preprint servers were searched up to November 25th, 2023. Articles investigating the persistence of SARS-CoV-2 RNA in plasma, stool, urine or nasal/oral swab samples in patients with post-COVID symptoms were included. Methodological quality was assessed using the Newcastle-Ottawa Scale or Cochrane's Risk of Bias (Rob) tool.

SUMMARY

From 322 studies identified, six studies met all inclusion criteria. The sample included 678 COVID-19 survivors (52 % female, aged from 29 to 66 years). The methodological quality was moderate in 88 % of the studies (n=5/6). Three papers investigated the presence of SARS-CoV-2 RNA in plasma, three studies in nasal/oral swabs, two studies in stool samples, one in urine and one in saliva. The follow-up was shorter than two months (<60 days after) in 66 % of the studies (n=4/6). The prevalence of SARS-CoV-2 RNA ranged from 5 to 59 % in patients with post-COVID symptoms the first two months after infection, depending on the sample tested, however, SARS-CoV-2 RNA was also identified in COVID-19 survivors without post-COVID symptoms (one study).

OUTLOOK

Available evidence can suggest the presence of persistent SARS-CoV-2 RNA in post-COVID patients in the short term, although the biases within the studies do not permit us to make firm assumptions. The association between post-COVID symptoms and SARS-CoV-2 RNA in the samples tested is also conflicting. The lack of comparative group without post-COVID symptoms limits the generalizability of viral persistence in post-COVID-19 condition.

Host factors of SARS-CoV-2 in infection, pathogenesis, and long-term effects

SARS-CoV-2 is the causative virus of the devastating COVID-19 pandemic that results in an unparalleled global health and economic crisis. Despite unprecedented scientific efforts and therapeutic interventions, the fight against COVID-19 continues as the rapid emergence of different SARS-CoV-2 variants of concern and the increasing challenge of long COVID-19, raising a vast demand to understand the pathomechanisms of COVID-19 and its long-term sequelae and develop therapeutic strategies beyond the virus per se. Notably, in addition to the virus itself, the replication cycle of SARS-CoV-2 and clinical severity of COVID-19 is also governed by host factors. In this review, we therefore comprehensively overview the replication cycle and pathogenesis of SARS-CoV-2 from the perspective of host factors and host-virus interactions. We sequentially outline the pathological implications of molecular interactions between host factors and SARS-CoV-2 in multi-organ and multi-system long COVID-19, and summarize current therapeutic strategies and agents targeting host factors for treating these diseases. This knowledge would be key for the identification of new pathophysiological aspects and mechanisms, and the development of actionable therapeutic targets and strategies for tackling COVID-19 and its sequelae.

COVID-19: Unveiling the Neuropsychiatric Maze-From Acute to Long-Term Manifestations

The SARS-CoV-2 virus has spread rapidly despite implementing strategies to reduce its transmission. The disease caused by this virus has been associated with a diverse range of symptoms, including common neurological manifestations such as dysgeusia, anosmia, and myalgias. Additionally, numerous cases of severe neurological complications associated with this disease have been reported, including encephalitis, stroke, seizures, and Guillain-Barré syndrome, among others. Given the high prevalence of neurological manifestations in this disease, the objective of this review is to analyze the mechanisms by which this virus can affect the nervous system, from its direct invasion to aberrant activation of the immune system and other mechanisms involved in the symptoms, including neuropsychiatric manifestations, to gain a better understanding of the disease and thus facilitate the search for effective therapeutic strategies.

Post-COVID-19 Condition in Military Personnel

INTRODUCTION

During the COVID-19 pandemic, a significant number of individuals experienced persistent symptoms, collectively termed post-COVID-19 condition (PCC) by the World Health Organization. While civilian prevalence has been extensively studied, little is known about PCC in military personnel. This article highlights the need for increased awareness, documentation, and research on PCC within the military context, utilizing the Defense Health Agency database.

MATERIALS AND METHODS

A keyword search of the PubMed, CINAHL, and Web of Science databases was performed utilizing the keywords: military, post-COVID conditions, long COVID-19, and post-COVID19 syndrome. A five-stage integrative review framework was used to analyze 40 reports and research articles published from 2019 to 2023 to assess the current state of PCC research, including epidemiology, severe acute respiratory syndrome coronavirus 2 variants, pathophysiology, and prevalence in military personnel.

RESULTS

Our review revealed a notable gap in research on PCC within the military population, with only a few mentions in the literature. A key finding was the association between immunization status, symptom severity, and ethnicity in PCC development.

CONCLUSION

To comprehensively address PCC in military personnel, it is imperative to foster both awareness and documentation. Creating a centralized Defense Health Agency-DoD repository for active duty service members with PCC diagnoses offers a valuable opportunity to conduct trend analysis, identify missed cases, and better understand the individual and military readiness implications of this condition. Additionally, to address the educational needs of clinicians, it is essential to develop continuing medical education and continuing nursing education programs focusing on PCC signs, symptoms, and their impact on readiness. Furthermore, randomized controlled trials and longitudinal experimental clinical trials are essential for monitoring service members over time, providing valuable insights into the course of PCC and potential interventions. These research endeavors collectively contribute to improving the health, readiness, and care of military personnel affected by PCC.