High-dimensional characterization of post-acute sequelae of COVID-19

Identifying Post-Acute Sequelae of SARS-CoV-2 Among Children in New York State Medicaid Managed Care

Persons who contract COVID-19 are at risk of developing post-acute sequelae of SARS-CoV-2 (PASC). The objective of this study was to describe the incidence of PASC in a pediatric Medicaid population. Using a retrospective cohort of children enrolled in New York State Medicaid Managed Care we compared incident diagnoses between children with a positive laboratory test for SARS-CoV-2 in 2021 to children without a positive test in 2021 and children with a viral respiratory diagnosis in 2019. Logistic regression models estimated adjusted odds ratios using the Cohen's d statistic to assess the strength of associations. Most unadjusted incidence of clinical outcomes were less than 1% for all cohorts. Relative to the 2021 comparison cohort, significant increases among SARS-CoV-2 cases were observed in sequela of infectious disease conditions, general signs and symptoms, and pericarditis and pericardial disease and for the 2019 comparison, sequela of infectious disease conditions and suicidal ideation. However, associations were mostly determined to be weak or marginal. In this low socioeconomic status pediatric population, incidence of new clinical sequelae was low with mostly weak or marginal increases associated with SARS-CoV-2 infection. Though the incidence was low, some outcomes may be severe. Observed associations may have been impacted by pandemic behavior modification including social distancing policies.

Structural basis of rosmarinic acid inhibitory mechanism on SARS-CoV-2 main protease

The SARS-CoV-2 coronavirus is characterized by high mutation rates and significant infectivity, posing ongoing challenges for therapeutic intervention. To address potential challenges in the future, the continued development of effective drugs targeting SARS-CoV-2 remains an important task for the scientific as well as the pharmaceutical community. The main protease (Mpro) of SARS-CoV-2 is an ideal therapeutic target for COVID-19 drug development, leading to the introduction of various inhibitors, both covalent and non-covalent, each characterized by unique mechanisms of action and possessing inherent strengths and limitations. Natural products, being compounds naturally present in the environment, offer advantages such as low toxicity and diverse activities, presenting a viable source for antiviral drug development. Here, we identified a natural compound, rosmarinic acid, which exhibits significant inhibitory effects on the Mpro of the SARS-CoV-2. Through detailed structural biology analysis, we elucidated the precise crystal structure of the complex formed between rosmarinic acid and SARS-CoV-2 Mpro, revealing the molecular basis of its inhibitory mechanism. These findings not only enhance our understanding of the antiviral action of rosmarinic acid, but also provide valuable structural information and mechanistic insights for the further development of therapeutic strategies against SARS-CoV-2.

A Practical Approach to Tailor the Term Long COVID for Diagnostics, Therapy and Epidemiological Research for Improved Long COVID Patient Care

The term long COVID (LC) effectively describes the broad long-term disease burden of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infections, encompassing individual suffering and significant socioeconomic impacts. However, its general use hampers precise epidemiological research, diagnostics and therapeutic strategies. Misinterpretations occur, for example, when population surveys are compared to studies using health record data, because both refer to these data as LC. This also emphasizes the need for different terminology. The National Institute for Health and Care Excellence (NICE) rapid guideline differentiates ongoing symptomatic COVID-19 from post-COVID conditions, yet real-world observations challenge these two subgroup definitions. We propose refining the term LC into three subgroups: ongoing symptomatic COVID-19, SARS-CoV-2 induced or exacerbated diseases and post-acute COVID condition. This stratification aids targeted diagnostics, treatment and epidemiological research. Subgroup-specific documentation using the International Classification of Diseases, Tenth Revision (ICD-10) codes ensures accurate tracking and understanding of long-term effects. The subgroup of post-acute COVID condition again includes various symptoms, syndromes and diseases like post-exertional malaise (PEM), dysautonomia or cognitive dysfunctions. In this regard, differentiation, especially considering PEM, is crucial for effective diagnostics and treatment.

Cardiovascular Manifestations of Long COVID: A Review

The acute phase of severe acute respiratory syndrome coronavirus 2 [coronavirus disease (COVID)] infection has many well-documented cardiovascular manifestations, however, the long-term sequelae are less understood. In this focused review, we explore the risk factors, character, and rates of cardiovascular events in patients with Long COVID, which is defined as symptoms occurring more than 4 weeks following initial infection. Research has identified increased rates of cerebrovascular disease, dysrhythmias, ischemic and inflammatory heart disease, cardiopulmonary symptoms, and thrombotic events among those with Long COVID, though the risk rates and potential mechanisms behind each cardiovascular event vary. Finally, we discuss the current gaps in the literature as well as how COVID compares to other viral infections when it comes to causing long-term cardiovascular sequelae.

Kotton C, V. Riella L. Post-acute Sequelae of COVID-19 Among Solid Organ Transplant Recipients: Insights From the Omicron Period

Background

In solid organ transplant recipients (SOTRs), studies investigating post-acute sequelae of SARS-CoV-2 infection (PASC) are limited, and risk factors for their development require further investigation.

Methods

In this cross-sectional study, we evaluated PASC symptoms among SOTRs followed at our institutions who had COVID-19 during the Omicron period from December 28, 2021, to November 4, 2022. Participants were surveyed using a newly published PASC score containing 13 symptoms experienced for ≥30 d. PASC was defined as a score of ≥12.

Results

Of 299 SOTRs invited, 93 completed the survey and were analyzed. The mean age was 58 y and 43% were women. Forty-six individuals (49%) reported experiencing ≥1 PASC symptom for ≥30 d, of whom 13 (14%) met the PASC definition. Multivariable analysis showed that female sex (adjusted odds ratio [aOR] = 0.32; 95% confidence interval [CI], 0.12-0.83), years from transplantation (aOR = 0.90 per additional year; 95% CI, 0.81-0.99), and tixagevimab-cilgavimab preexposure prophylaxis (aOR = 0.33; 95% CI, 0.12-0.84) were associated with significantly lower odds of developing ≥1 PASC symptom.

Conclusions

PASC symptoms are common in SOTRs infected during the Omicron period. PASC symptoms are less frequent in those with a longer time since transplant and in those who received tixagevimab-cilgavimab. New SARS-CoV-2 prevention and treatment strategies should also evaluate PASC symptoms as outcomes.

Covid-19 Anxiety Scale (CAS): A Validity and Reliability Study

In this study, our aim was to develop a valid and reliable scale to determine the social anxiety level of people regarding COVID-19. A total of 420 people participated in the research. Explanatory and confirmatory factor analyses were used to test the validity and reliability of the scale. As a result of the explanatory factor analysis, it was determined that the scale consisted of 22 items and four sub-dimensions. These sub-dimensions were named "negative thinking", "sociability", "fear" and "vaccination". In examination of the fit indices obtained from the confirmatory factor analysis results, it was seen that the four-factor scale structure was high and acceptable. Based on these results, we concluded that the COVID-19 social anxiety scale (CAS) was valid and reliable for examining the level of social anxiety of people during the pandemic periods.

Non-Covalent Inhibitors of SARS-CoV-2 Papain-Like Protease (PLpro): In Vitro and In Vivo Antiviral Activity

The SARS-CoV-2 papain-like protease (PLpro), essential for viral processing and immune response disruption, is a promising target for treating acute infection of SARS-CoV-2. To date, there have been no reports of PLpro inhibitors with both submicromolar potency and animal model efficacy. To address the challenge of PLpro's featureless active site, a noncovalent inhibitor library with over 50 new analogs was developed, targeting the PLpro active site by modulating the BL2-loop and engaging the BL2-groove. Notably, compounds 42 and 10 exhibited strong antiviral effects and were further analyzed pharmacokinetically. 10, in particular, showed a significant lung accumulation, up to 12.9-fold greater than plasma exposure, and was effective in a mouse model of SARS-CoV-2 infection, as well as against several SARS-CoV-2 variants. These findings highlight the potential of 10 as an in vivo chemical probe for studying PLpro inhibition in SARS-CoV-2 infection.

Characteristics Associated With Long-Term Outcomes in Severe COVID-19 Patients After a Post-Acute Care Hospitalization: A Prospective Cohort Study

OBJECTIVES

To describe characteristics associated with long-term outcomes in severe COVID-19 patients admitted to a post-acute care facility (PACF).

DESIGN

Prospective cohort.

SETTING AND PARTICIPANTS

Consecutive severe COVID-19 admitted to a PACF from April 2020 to August 2021.

METHODS

Patients were followed for 180 days after discharge. Functional outcomes were measured by the modified Barthel index and further stratified into good outcome (for those independent, mildly dependent, or moderately dependent) and into bad outcome (for those severely dependent, completely dependent, or dead). Multivariate binary logistic regression was performed to evaluate between patients' characteristics and long-term outcomes.

RESULTS

A total of 186 patients admitted from 17 different acute hospitals were included. Median age was 67 years, 88% of patients were previously independent, 95% were admitted to the ICU, and 85% were mechanically ventilated during the acute hospitalization. Median (interquartile range) Barthel indexes at admission, discharge, and 180-day follow-up were 9 (1-23), 81 (45-92), and 100 (98-100) (P < .001), respectively. In addition, 180-day mortality was 17.2%. Baseline functional status, comorbidities, and functional status at admission to the PACF were associated with bad outcome at 180-day follow-up, after multivariate binary logistic regression.

CONCLUSIONS AND IMPLICATIONS

Patients with severe COVID-19 admitted to a PACF had substantial functional improvements at PACF discharge and during 180-day follow-up. These findings may help prognosticate and manage post-acute severe COVID-19 patients.

Predicting Long COVID in the National COVID Cohort Collaborative Using Super Learner: Cohort Study

BACKGROUND

Postacute sequelae of COVID-19 (PASC), also known as long COVID, is a broad grouping of a range of long-term symptoms following acute COVID-19. These symptoms can occur across a range of biological systems, leading to challenges in determining risk factors for PASC and the causal etiology of this disorder. An understanding of characteristics that are predictive of future PASC is valuable, as this can inform the identification of high-risk individuals and future preventative efforts. However, current knowledge regarding PASC risk factors is limited.

OBJECTIVE

Using a sample of 55,257 patients (at a ratio of 1 patient with PASC to 4 matched controls) from the National COVID Cohort Collaborative, as part of the National Institutes of Health Long COVID Computational Challenge, we sought to predict individual risk of PASC diagnosis from a curated set of clinically informed covariates. The National COVID Cohort Collaborative includes electronic health records for more than 22 million patients from 84 sites across the United States.

METHODS

We predicted individual PASC status, given covariate information, using Super Learner (an ensemble machine learning algorithm also known as stacking) to learn the optimal combination of gradient boosting and random forest algorithms to maximize the area under the receiver operator curve. We evaluated variable importance (Shapley values) based on 3 levels: individual features, temporal windows, and clinical domains. We externally validated these findings using a holdout set of randomly selected study sites.

RESULTS

We were able to predict individual PASC diagnoses accurately (area under the curve 0.874). The individual features of the length of observation period, number of health care interactions during acute COVID-19, and viral lower respiratory infection were the most predictive of subsequent PASC diagnosis. Temporally, we found that baseline characteristics were the most predictive of future PASC diagnosis, compared with characteristics immediately before, during, or after acute COVID-19. We found that the clinical domains of health care use, demographics or anthropometry, and respiratory factors were the most predictive of PASC diagnosis.

CONCLUSIONS

The methods outlined here provide an open-source, applied example of using Super Learner to predict PASC status using electronic health record data, which can be replicated across a variety of settings. Across individual predictors and clinical domains, we consistently found that factors related to health care use were the strongest predictors of PASC diagnosis. This indicates that any observational studies using PASC diagnosis as a primary outcome must rigorously account for heterogeneous health care use. Our temporal findings support the hypothesis that clinicians may be able to accurately assess the risk of PASC in patients before acute COVID-19 diagnosis, which could improve early interventions and preventive care. Our findings also highlight the importance of respiratory characteristics in PASC risk assessment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1101/2023.07.27.23293272.

A practical framework for Long COVID treatment in primary care

Long COVID is a complex, multisystem illness with a poorly understood pathophysiology, absence of specific diagnostic tests or criteria, or evidence-based treatments. With over 200 identified symptoms and approximately 10% of COVID-19 cases resulting in Long COVID, it is a challenge to provide comprehensive treatment at a scale commensurate with the illness burden. The diverse manifestations of Long COVID, encompassing numerous medical specialties, typically place primary care providers (PCPs) at the forefront of management, navigating an evolving landscape of research and lack of evidence-based guidelines. This paper presents a pragmatic, structured framework for Long COVID management in primary care, integrating current knowledge and best practices. The approach is individualized, addressing Long COVID's broad symptomatology through a four-step framework. The first step focuses on energy management strategies, emphasizing the prevention of post-exertional malaise, a cardinal feature of Long COVID. The second step, intentional rehabilitation, employs carefully titrated multidisciplinary modalities to address physical, cognitive, and emotional domains. The third step utilizes symptomatic management through both pharmacological and non-pharmacological interventions, targeting debilitating symptoms like fatigue, insomnia, and chronic pain. The fourth step outlines an approach to trialing experimental, targeted therapies that may impact Long COVID's underlying pathophysiology. These treatments, while experimental and lacking quality evidence in Long COVID, may be available off-label on an individual basis following a thorough risk-benefit discussion. This stepwise framework can equip PCPs to effectively address the most common and disabling symptoms of Long COVID, individualize care, and remain attuned to the evolving scientific understanding of the condition.

Long-term impacts of COVID-19 in patients with prior heart failure in Korea: A nationwide cohort study using the common data model

Limited data are available on the long-term prognosis and monitoring period after coronavirus disease 2019 (COVID-19) infection in the population with prior heart failure (HF). We aimed to exam the association of COVID-19 with clinical prognosis in populations with prior HF and evaluate prognosis within 30 days and 30 days to 1 year after infection. Based on insurance benefit claims sent to the Health Insurance Review and Assessment Service of Korea from January 2018 to April 2022, 9,822,577 patients were selected and converted to the Observational Medical Outcomes Partnership-common data model by the Big Data Department of Health Insurance Review and Assessment Service of Korea. In the dataset, 1,565,274 patients exhibited diagnosis of HF based on the International Statistical Classification of Diseases and Related Health Problems 10 codes. They were divided into 2 groups according to COVID-19 infection, and propensity-score-matching analysis was performed. The clinical outcome was all-cause mortality. Among the 1,565,274 patients with an HF diagnosis, 1,152,975 patients were classified into the HF with the COVID-19 group and 412,299 patients in the HF without COVID-19 group. We created 200,780 matched pairs by propensity-score-matching analysis. Within 30 days of COVID-19, the HF with COVID-19 group had a higher risk of all-cause death compared with the HF without COVID-19 group (hazard ratio [HR]: 2.19, 95% confidence interval [CI]: 2.04-2.36, P < .01). Thirty days to 1 year after COVID-19 infection, the HF with COVID-19 group exhibited a higher risk of all-cause death (HR: 2.04, 95% CI: 1.83-2.27, P < .01). In populations with prior HF, COVID-19 is associated with a higher risk of all-cause mortality within 30 days and this risk remains augmented up to 1 year after the acute phase of COVID-19. Our findings suggest that greater attention may be crucial in populations with prior HF for a prolonged period after COVID-19 infection.

Potential use of sodium glucose co-transporter 2 inhibitors during acute illness: a systematic review based on COVID-19

OBJECTIVE

SGLT-2i are increasingly recognized for their benefits in patients with cardiometabolic risk factors. Additionally, emerging evidence suggests potential applications in acute illnesses, including COVID-19. This systematic review aims to evaluate the effects of SGLT-2i in patients facing acute illness, particularly focusing on SARS-CoV-2 infection.

METHODS

Following PRISMA guidelines, a systematic search of PubMed, Scopus, medRxiv, Research Square, and Google Scholar identified 22 studies meeting inclusion criteria, including randomized controlled trials and observational studies. Data extraction and quality assessment were conducted independently.

RESULTS

Out of the 22 studies included in the review, six reported reduced mortality in DM-2 patients taking SGLT-2i, while two found a decreased risk of hospitalization. Moreover, one study demonstrated a lower in-hospital mortality rate in DM-2 patients under combined therapy of metformin plus SGLT-2i. However, three studies showed a neutral effect on the risk of hospitalization. No increased risk of developing COVID-19 was associated with SGLT-2i use in DM-2 patients. Prior use of SGLT-2i was not associated with ICU admission and need for MV. The risk of acute kidney injury showed variability, with inconsistent evidence regarding diabetic ketoacidosis.

CONCLUSION

Our systematic review reveals mixed findings on the efficacy of SGLT-2i use in COVID-19 patients with cardiometabolic risk factors. While some studies suggest potential benefits in reducing mortality and hospitalizations, others report inconclusive results. Further research is needed to clarify optimal usage and mitigate associated risks, emphasizing caution in clinical interpretation.

COVID-19 Neuroimaging Update: Pathophysiology, Acute Findings, and Post-Acute Developments

COVID-19 has prominent effects on the nervous system with important manifestations on neuroimaging. In this review, we discuss the neuroimaging appearance of acute COVID-19 that became evident during the early stages of the pandemic. We highlight the underlying pathophysiology mediating nervous system effects and neuroimaging appearances including systemic inflammatory response such as cytokine storm, coagulopathy, and para/post-infections immune mediated phenomena. We also discuss the nervous system manifestations of COVID-19 and the role of imaging as the pandemic has evolved over time, including related to the development of vaccines and the emergence of post-acute sequalae such as long COVID.

Long COVID science, research and policy

Long COVID represents the constellation of post-acute and long-term health effects caused by SARS-CoV-2 infection; it is a complex, multisystem disorder that can affect nearly every organ system and can be severely disabling. The cumulative global incidence of long COVID is around 400 million individuals, which is estimated to have an annual economic impact of approximately $1 trillion-equivalent to about 1% of the global economy. Several mechanistic pathways are implicated in long COVID, including viral persistence, immune dysregulation, mitochondrial dysfunction, complement dysregulation, endothelial inflammation and microbiome dysbiosis. Long COVID can have devastating impacts on individual lives and, due to its complexity and prevalence, it also has major ramifications for health systems and economies, even threatening progress toward achieving the Sustainable Development Goals. Addressing the challenge of long COVID requires an ambitious and coordinated-but so far absent-global research and policy response strategy. In this interdisciplinary review, we provide a synthesis of the state of scientific evidence on long COVID, assess the impacts of long COVID on human health, health systems, the economy and global health metrics, and provide a forward-looking research and policy roadmap.

COVID-19 in the Initiation and Progression of Atherosclerosis: Pathophysiology During and Beyond the Acute Phase

The incidence of atherosclerotic cardiovascular disease is increasing globally, especially in low- and middle-income countries, despite significant efforts to reduce traditional risk factors. Premature subclinical atherosclerosis has been documented in association with several viral infections. The magnitude of the recent COVID-19 pandemic has highlighted the need to understand the association between SARS-CoV-2 and atherosclerosis. This review examines various pathophysiological mechanisms, including endothelial dysfunction, platelet activation, and inflammatory and immune hyperactivation triggered by SARS-CoV-2 infection, with specific attention on their roles in initiating and promoting the progression of atherosclerotic lesions. Additionally, it addresses the various pathogenic mechanisms by which COVID-19 in the post-acute phase may contribute to the development of vascular disease. Understanding the overlap of these syndromes may enable novel therapeutic strategies. We further explore the need for guidelines for closer follow-up for the often-overlooked evidence of atherosclerotic cardiovascular disease among patients with recent COVID-19, particularly those with cardiometabolic risk factors.

Blood DNA methylation in post-acute sequelae of COVID-19 (PASC): a prospective cohort study

BACKGROUND

DNA methylation integrates environmental signals with transcriptional programs. COVID-19 infection induces changes in the host methylome. While post-acute sequelae of COVID-19 (PASC) is a long-term complication of acute illness, its association with DNA methylation is unknown. No universal blood marker of PASC, superseding single organ dysfunctions, has yet been identified.

METHODS

In this single centre prospective cohort study, PASC, post-COVID without PASC, and healthy participants were enrolled to investigate their symptoms association with peripheral blood DNA methylation data generated with state-of-the-art whole genome sequencing. PASC-induced quality-of-life deterioration was scored with a validated instrument, SF-36. Analyses were conducted to identify potential functional roles of differentially methylated loci, and machine learning algorithms were used to resolve PASC severity.

FINDINGS

103 patients with PASC (22.3% male, 77.7% female), 15 patients with previous COVID-19 infection but no PASC (40.0% male, 60.0% female), and 27 healthy volunteers (48.1% male, 51.9% female) were enrolled. Whole genome methylation sequencing revealed 39 differentially methylated regions (DMRs) specific to PASC, each harbouring an average of 15 consecutive positions, that differentiate patients with PASC from the two control groups. Motif analyses of PASC-regulated DMRs identify binding domains for transcription factors regulating circadian rhythm and others. Some DMRs annotated to protein coding genes were associated with changes of RNA expression. Machine learning support vector algorithm and random forest hierarchical clustering reveal 28 unique differentially methylated positions (DMPs) in the genome discriminating patients with better and worse quality of life.

INTERPRETATION

Blood DNA methylation levels identify PASC, stratify PASC severity, and suggest that DNA motifs are targeted by circadian rhythm-regulating pathways in PASC.

FUNDING

This project has been funded by the following agencies: NIH-AI173035 (A. Jaitovich and R. Alisch); and NIH-AG066179 (R. Alisch).

Psychosocial Factors Associated With Long-Term Cognitive Impairment Among COVID-19 Survivors: A Cross-Sectional Study

ABSTRACT

COVID-19 survivors complained of the experience of cognitive impairments, which also called "brain fog" even recovered. The study aimed to describe long-term cognitive change and determine psychosocial factors in COVID-19 survivors. A cross-sectional study was recruited 285 participants from February 2020 to April 2020 in 17 hospitals in Sichuan Province. Cognitive function, variables indicative of the virus infection itself, and psychosocial variables were collected by telephone interview. Univariate logistic regression and Lasso logistic regression models were used for variable selection which plugged into a multiple logistics model. Overall prevalence of moderate or severe cognitive impairment was 6.3%. Logistic regression showed that sex, religion, smoking status, occupation, self-perceived severity of illness, sleep quality, perceived mental distress after COVID-19, perceived discrimination from relatives and friends, and suffered abuse were associated with cognitive impairment. The long-term consequences of cognitive function are related to multiple domains, in which psychosocial factors should be taken into consideration.

Short- and long-term neuropsychiatric outcomes in long COVID in South Korea and Japan

We investigated whether SARS-CoV-2 infection is associated with short- and long-term neuropsychiatric sequelae. We used population-based cohorts from the Korean nationwide cohort (discovery; n = 10,027,506) and the Japanese claims-based cohort (validation; n = 12,218,680) to estimate the short-term (<30 days) and long-term (≥30 days) risks of neuropsychiatric outcomes after SARS-CoV-2 infection compared with general population groups or external comparators (people with another respiratory infection). Using exposure-driven propensity score matching, we found that both the short- and long-term risks of developing neuropsychiatric sequelae were elevated in the discovery cohort compared with the general population and those with another respiratory infection. A range of conditions including Guillain-Barré syndrome, cognitive deficit, insomnia, anxiety disorder, encephalitis, ischaemic stroke and mood disorder exhibited a pronounced increase in long-term risk. Factors such as mild severity of COVID-19, increased vaccination against COVID-19 and heterologous vaccination were associated with reduced long-term risk of adverse neuropsychiatric outcomes. The time attenuation effect was the strongest during the first six months after SARS-CoV-2 infection, and this risk remained statistically significant for up to one year in Korea but beyond one year in Japan. The associations observed were replicated in the validation cohort. Our findings contribute to the growing evidence base on long COVID by considering ethnic diversity.

Use of a risk assessment tool to determine the origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

The origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is contentious. Most studies have focused on a zoonotic origin, but definitive evidence such as an intermediary animal host is lacking. We used an established risk analysis tool for differentiating natural and unnatural epidemics, the modified Grunow-Finke assessment tool (mGFT) to study the origin of SARS-COV-2. The mGFT scores 11 criteria to provide a likelihood of natural or unnatural origin. Using published literature and publicly available sources of information, we applied the mGFT to the origin of SARS-CoV-2. The mGFT scored 41/60 points (68%), with high inter-rater reliability (100%), indicating a greater likelihood of an unnatural than natural origin of SARS-CoV-2. This risk assessment cannot prove the origin of SARS-CoV-2 but shows that the possibility of a laboratory origin cannot be easily dismissed.

Modifiable lifestyle factors and the risk of post-COVID-19 multisystem sequelae, hospitalization, and death

Effective prevention strategies for post-COVID complications are crucial for patients, clinicians, and policy makers to mitigate their cumulative burden. This study evaluated the association of modifiable lifestyle factors (smoking, alcohol intake, BMI, physical activity, sedentary time, sleep duration, and dietary habits) with COVID-19 multisystem sequelae, death, and hospitalization in the UK Biobank cohort (n = 68,896). A favorable lifestyle (6-10 healthy factors; 46.4%) was associated with a 36% lower risk of multisystem sequelae (HR, 0.64; 95% CI, 0.58-0.69; ARR at 210 days, 7.08%; 95% CI, 5.98-8.09) compared to an unfavorable lifestyle (0-4 factors; 12.3%). Risk reductions spanned all 10 organ systems, including cardiovascular, coagulation, metabolic, gastrointestinal, kidney, mental health, musculoskeletal, respiratory disorders, and fatigue. This beneficial effect was largely attributable to direct lifestyle impacts independent of corresponding pre-infection comorbidities (71% for any sequelae). A favorable lifestyle was also related to the risk of post-COVID death (HR 0.59, 0.52-0.66) and hospitalization (HR 0.78, 0.73-0.84). These associations persisted across acute and post-acute infection phases, irrespective of hospitalization status, vaccination, or SARS-CoV-2 variant. These findings underscore the clinical and public health importance of adhering to a healthy lifestyle in mitigating long-term COVID-19 adverse impacts and enhancing future pandemic preparedness.

Sample-to-Answer Detection of SARS-CoV-2 Viremia Using Thermally Responsive Alkane Partitions

The diagnosis of bloodborne viral infections (viremia) is currently relegated to central laboratories because of the complex procedures required to detect viruses in blood samples. The development of point-of-care diagnostics for viremia would enable patients to receive a diagnosis and begin treatment immediately instead of waiting days for results. Point-of-care systems for viremia have been limited by the challenges of integrating multiple precise steps into a fully automated (i.e., sample-to-answer), compact, low-cost system. We recently reported the development of thermally responsive alkane partitions (TRAPs), which enable the complete automation of diagnostic assays with complex samples. Here we report the use of TRAPs for the sample-to-answer detection of viruses in blood using a low-cost portable device and easily manufacturable cassettes. Specifically, we demonstrate the detection of SARS-CoV-2 in spiked blood samples, and we show that our system detects viremia in COVID-19 patient samples with good agreement to conventional RT-qPCR. We anticipate that our sample-to-answer system can be used to rapidly diagnose SARS-CoV-2 viremia at the point of care, leading to better health outcomes for patients with severe COVID-19 disease, and that our system can be applied to the diagnosis of other life-threatening bloodborne viral diseases, including Hepatitis C and HIV.

Inflammation in the COVID-19 airway is due to inhibition of CFTR signaling by the SARS-CoV-2 spike protein

SARS-CoV-2-contributes to sickness and death in COVID-19 patients partly by inducing a hyper-proinflammatory immune response in the host airway. This hyper-proinflammatory state involves activation of signaling by NFκB, and unexpectedly, ENaC, the epithelial sodium channel. Post-infection inflammation may also contribute to "Long COVID"/PASC. Enhanced signaling by NFκB and ENaC also marks the airway of patients suffering from cystic fibrosis, a life-limiting proinflammatory genetic disease due to inactivating mutations in the CFTR gene. We therefore hypothesized that inflammation in the COVID-19 airway might similarly be due to inhibition of CFTR signaling by SARS-CoV-2 spike protein, and therefore activation of both NFκB and ENaC signaling. We used western blot and electrophysiological techniques, and an organoid model of normal airway epithelia, differentiated on an air-liquid-interface (ALI). We found that CFTR protein expression and CFTR cAMP-activated chloride channel activity were lost when the model epithelium was exposed to SARS-CoV-2 spike proteins. As hypothesized, the absence of CFTR led to activation of both TNFα/NFκB signaling and α and γ ENaC. We had previously shown that the cardiac glycoside drugs digoxin, digitoxin and ouabain blocked interaction of spike protein and ACE2. Consistently, addition of 30 nM concentrations of the cardiac glycoside drugs, prevented loss of both CFTR protein and CFTR channel activity. ACE2 and CFTR were found to co-immunoprecipitate in both basal cells and differentiated epithelia. Thus spike-dependent CFTR loss might involve ACE2 as a bridge between Spike and CFTR. In addition, spike exposure to the epithelia resulted in failure of endosomal recycling to return CFTR to the plasma membrane. Thus, failure of CFTR recovery from endosomal recycling might be a mechanism for spike-dependent loss of CFTR. Finally, we found that authentic SARS-CoV-2 virus infection induced loss of CFTR protein, which was rescued by the cardiac glycoside drugs digitoxin and ouabain. Based on experiments with this organoid model of small airway epithelia, and comparisons with 16HBE14o- and other cell types expressing normal CFTR, we predict that inflammation in the COVID-19 airway may be mediated by inhibition of CFTR signaling by the SARS-CoV-2 spike protein, thus inducing a cystic fibrosis-like clinical phenotype. To our knowledge this is the first time COVID-19 airway inflammation has been experimentally traced in normal subjects to a contribution from SARS-CoV-2 spike-dependent inhibition of CFTR signaling.

Molecular overlaps of neurological manifestations of COVID-19 and schizophrenia from a proteomic perspective

COVID-19, a complex multisystem disorder affecting the central nervous system, can also have psychiatric sequelae. In addition, clinical evidence indicates that a diagnosis of a schizophrenia spectrum disorder is a risk factor for mortality in patients with COVID-19. In this study, we aimed to explore brain-specific molecular aspects of COVID-19 by using a proteomic approach. We analyzed the brain proteome of fatal COVID-19 cases and compared it with differentially regulated proteins found in postmortem schizophrenia brains. The COVID-19 proteomic dataset revealed a strong enrichment of proteins expressed by glial and neuronal cells and processes related to diseases with a psychiatric and neurodegenerative component. Specifically, the COVID-19 brain proteome enriches processes that are hallmark features of schizophrenia. Furthermore, we identified shared and distinct molecular pathways affected in both conditions. We found that brain ageing processes are likely present in both COVID-19 and schizophrenia, albeit possibly driven by distinct processes. In addition, alterations in brain cell metabolism were observed, with schizophrenia primarily impacting amino acid metabolism and COVID-19 predominantly affecting carbohydrate metabolism. The enrichment of metabolic pathways associated with astrocytic components in both conditions suggests the involvement of this cell type in the pathogenesis. Both COVID-19 and schizophrenia influenced neurotransmitter systems, but with distinct impacts. Future studies exploring the underlying mechanisms linking brain ageing and metabolic dysregulation may provide valuable insights into the complex pathophysiology of these conditions and the increased vulnerability of schizophrenia patients to severe outcomes.

Postacute Sequelae of SARS-CoV-2 Infection in the Pre-Delta, Delta, and Omicron Eras

BACKGROUND

Postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) can affect many organ systems. However, temporal changes during the coronavirus disease 2019 (Covid-19) pandemic, including the evolution of SARS-CoV-2, may have affected the risk and burden of PASC. Whether the risk and burden of PASC have changed over the course of the pandemic is unclear.

METHODS

We used health records of the Department of Veterans Affairs to build a study population of 441,583 veterans with SARS-CoV-2 infection between March 1, 2020, and January 31, 2022, and 4,748,504 noninfected contemporaneous controls. We estimated the cumulative incidence of PASC at 1 year after SARS-CoV-2 infection during the pre-delta, delta, and omicron eras of the Covid-19 pandemic.

RESULTS

Among unvaccinated persons infected with SARS-CoV-2, the cumulative incidence of PASC during the first year after infection was 10.42 events per 100 persons (95% confidence interval [CI], 10.22 to 10.64) in the pre-delta era, 9.51 events per 100 persons (95% CI, 9.26 to 9.75) in the delta era, and 7.76 events per 100 persons (95% CI, 7.57 to 7.98) in the omicron era (difference between the omicron and pre-delta eras, -2.66 events per 100 persons [95% CI, -2.93 to -2.36]; difference between the omicron and delta eras, -1.75 events per 100 persons [95% CI, -2.08 to -1.42]). Among vaccinated persons, the cumulative incidence of PASC at 1 year was 5.34 events per 100 persons (95% CI, 5.10 to 5.58) during the delta era and 3.50 events per 100 persons (95% CI, 3.31 to 3.71) during the omicron era (difference between the omicron and delta eras, -1.83 events per 100 persons; 95% CI, -2.14 to -1.52). Vaccinated persons had a lower cumulative incidence of PASC at 1 year than unvaccinated persons (difference during the delta era, -4.18 events per 100 persons [95% CI, -4.47 to -3.88]; difference during the omicron era, -4.26 events per 100 persons [95% CI, -4.49 to -4.05]). Decomposition analyses showed 5.23 (95% CI, 4.97 to 5.47) fewer PASC events per 100 persons at 1 year during the omicron era than during the pre-delta and delta eras combined; 28.11% of the decrease (95% CI, 25.57 to 30.50) was attributable to era-related effects (changes in the virus and other temporal effects), and 71.89% (95% CI, 69.50 to 74.43) was attributable to vaccines.

CONCLUSIONS

The cumulative incidence of PASC during the first year after SARS-CoV-2 infection decreased over the course of the pandemic, but the risk of PASC remained substantial even among vaccinated persons who had SARS-CoV-2 infection in the omicron era. (Supported by the Department of Veterans Affairs.).

Quality of Sleep and Mental Symptoms Contribute to Health-Related Quality of Life after COVID-19 Pneumonia, a Follow-Up Study of More than 2 Years

A follow-up study was designed to assess correlations among physical signs, quality of sleep, common mental symptoms, and health-related quality of life after moderate to severe COVID-19 pneumonia. Daily changes in dyspnoea and pulse oximetry were recorded (200 days), and four evaluations (in >2 years) were performed on quality of sleep, mental symptoms, cognitive performance, and health-related quality of life. In a single center, 72 adults participated in the study (52.5 ± 13.7 years old), with no psychiatry/neurology/chronic lung/infectious diseases, chronic use of corticosteroids/immunosuppressive therapy, or pregnancy. Daily agendas showed delayed decreases in dyspnoea scores compared to pulse oximetry and heart rate recordings; however, changes in pulse oximetry were minimal. Slight changes in cognitive performance were related to the general characteristics of the participants (obesity and tobacco use) and with the severity of acute disease (MANCOVA, p < 0.001). Health-related quality of life gradually improved (MANCOVA, p < 0.004). During recovery, bad quality of sleep and mental symptoms (mainly attention/concentration) contributed to the subscores on health perception and vitality in the health-related quality of life assessment. Early mental support services including sleep hygiene could be beneficial during rehabilitation after acute COVID-19.

Identification of risk factors of Long COVID and predictive modeling in the RECOVER EHR cohorts

BACKGROUND

SARS-CoV-2-infected patients may develop new conditions in the period after the acute infection. These conditions, the post-acute sequelae of SARS-CoV-2 infection (PASC, or Long COVID), involve a diverse set of organ systems. Limited studies have investigated the predictability of Long COVID development and its associated risk factors.

METHODS

In this retrospective cohort study, we used electronic healthcare records from two large-scale PCORnet clinical research networks, INSIGHT (~1.4 million patients from New York) and OneFlorida+ (~0.7 million patients from Florida), to identify factors associated with having Long COVID, and to develop machine learning-based models for predicting Long COVID development. Both SARS-CoV-2-infected and non-infected adults were analysed during the period of March 2020 to November 2021. Factors associated with Long COVID risk were identified by removing background associations and correcting for multiple tests.

RESULTS

We observed complex association patterns between baseline factors and a variety of Long COVID conditions, and we highlight that severe acute SARS-CoV-2 infection, being underweight, and having baseline comorbidities (e.g., cancer and cirrhosis) are likely associated with increased risk of developing Long COVID. Several Long COVID conditions, e.g., dementia, malnutrition, chronic obstructive pulmonary disease, heart failure, PASC diagnosis U099, and acute kidney failure are well predicted (C-index > 0.8). Moderately predictable conditions include atelectasis, pulmonary embolism, diabetes, pulmonary fibrosis, and thromboembolic disease (C-index 0.7-0.8). Less predictable conditions include fatigue, anxiety, sleep disorders, and depression (C-index around 0.6).

CONCLUSIONS

This observational study suggests that association patterns between investigated factors and Long COVID are complex, and the predictability of different Long COVID conditions varies. However, machine learning-based predictive models can help in identifying patients who are at risk of developing a variety of Long COVID conditions.

New insights into healthy ageing, inflammageing and frailty using metabolomics

Human ageing is a normal process and does not necessarily result in the development of frailty. A mix of genetic, environmental, dietary, and lifestyle factors can have an impact on ageing, and whether an individual develops frailty. Frailty is defined as the loss of physiological reserve both at the physical and cellular levels, where systemic processes such as oxidative stress and inflammation contribute to physical decline. The newest "omics" technology and systems biology discipline, metabolomics, enables thorough characterisation of small-molecule metabolites in biological systems at a particular time and condition. In a biological system, metabolites-cellular intermediate products of metabolic reactions-reflect the system's final response to genomic, transcriptomic, proteomic, epigenetic, or environmental alterations. As a relatively newer technique to characterise metabolites and biomarkers in ageing and illness, metabolomics has gained popularity and has a wide range of applications. We will give a comprehensive summary of what is currently known about metabolomics in studies of ageing, with a focus on biomarkers for frailty. Metabolites related to amino acids, lipids, carbohydrates, and redox metabolism may function as biomarkers of ageing and/or frailty development, based on data obtained from human studies. However, there is a complexity that underpins biological ageing, due to both genetic and environmental factors that play a role in orchestrating the ageing process. Therefore, there is a critical need to identify pathways that contribute to functional decline in people with frailty.

Tissue-based T cell activation and viral RNA persist for up to 2 years after SARS-CoV-2 infection

The mechanisms of postacute medical conditions and unexplained symptoms after SARS-CoV-2 infection [Long Covid (LC)] are incompletely understood. There is growing evidence that viral persistence, immune dysregulation, and T cell dysfunction may play major roles. We performed whole-body positron emission tomography imaging in a well-characterized cohort of 24 participants at time points ranging from 27 to 910 days after acute SARS-CoV-2 infection using the radiopharmaceutical agent [18F]F-AraG, a selective tracer that allows for anatomical quantitation of activated T lymphocytes. Tracer uptake in the postacute COVID-19 group, which included those with and without continuing symptoms, was higher compared with prepandemic controls in many regions, including the brain stem, spinal cord, bone marrow, nasopharyngeal and hilar lymphoid tissue, cardiopulmonary tissues, and gut wall. T cell activation in the spinal cord and gut wall was associated with the presence of LC symptoms. In addition, tracer uptake in lung tissue was higher in those with persistent pulmonary symptoms specifically. Increased T cell activation in these tissues was also observed in many individuals without LC. Given the high [18F]F-AraG uptake detected in the gut, we obtained colorectal tissue for in situ hybridization of SARS-CoV-2 RNA and immunohistochemical studies in a subset of five participants with LC symptoms. We identified intracellular SARS-CoV-2 single-stranded spike protein-encoding RNA in rectosigmoid lamina propria tissue in all five participants and double-stranded spike protein-encoding RNA in three participants up to 676 days after initial COVID-19, suggesting that tissue viral persistence could be associated with long-term immunologic perturbations.

Habitual physical activity and COVID-19

BACKGROUND

Physical activity (PA) is known to decrease COVID-19 risk factors and can attenuate symptoms of viral infections. However, difficulty exercising and fatigue are common complaints after COVID-19. It is unknown whether prior habitual PA will improve outcomes and what the time course is until full recovery of PA after COVID-19.

METHODS

Invitations were emailed to 21,933 adults who were SARS-CoV-2 positive between March 2020 and February 2021. Participants completed intake surveys and the Physical Activity History (PAH) questionnaire regarding PA during the 3-month prior to infection. Monthly thereafter, for up to 23 months, participants were emailed surveys. Scores were computed for moderate and heavy PA. Long COVID (LC) was defined as having recurring/persistent symptoms 9 months after diagnosis.

RESULTS

Overall, 993 patients completed the intake survey (age 50.7±15.8 years, BMI 27.3±9.2, 58% women); 28% had been hospitalized. One-third had recovered to their pre-infection level of PA at 9 months post-infection; this increased to 65% at one year, and 90% at two years. Higher pre-diagnosis PA reduced odds of hospitalization (P<0.05) but not of LC. Factors predictive of poor PA recovery were higher pre-diagnosis PA, shortness of breath and fatigue during acute illness, and fatigue chronically. Participants who reported ongoing symptoms had consistently poorer recovery of habitual PA compared to those not reporting chronic symptoms.

CONCLUSIONS

Habitual PA reduced odds of hospitalization but not of LC. Thirty-five percent had not returned to pre-COVID-19 levels of PA one year after infection, representing a major public health threat.

Recovery from Severe COVID-19 Is an Independent Predictor of Electrocardiographic Abnormal P-Wave Axis

AIM

Abnormal P-wave axis (aPwa) have been correlated with an increased risk of supraventricular arrhythmias. The aim of this study was to analyze whether infection with COVID-19 may cause a predisposition for supraventricular arrhythmia in the long term, following recovery.

MATERIALS AND METHODS

In this study, a total of 252 subjects with a confirmed history of COVID-19 (recovered COVID-19) and 251 healthy subjects without a history of COVID-19 were included. The recovered COVID-19 group was divided into three subgroups designated as mild, moderate, and severe according to the severity score of their chest CT. The aPwa data were obtained using 12-lead electrocardiography (ECG) and compared between the healthy subjects and the recovered COVID-19 subgroups.

RESULTS

This study showed that in the recovered severe COVID-19 subgroup the prevalence of aPwa was significantly increased compared to the controls and the other COVID-19 subgroups. No correlation could be detected in Spearman's Rho correlation between the existence of aPwa and the number of positive PCR tests for COVID-19 and the time elapsed after infection with COVID-19. The binary logistic regression analysis showed that recovery from severe COVID-19, the severity score of the chest CT in the recovered from COVID-19 subjects, and the existence of hypertension (HT) were all independent predictors of aPwa (hazard ratio: 3.542, 95% confidence interval: 1.398-8.969, p: 0.01; hazard ratio: 0.896, 95% confidence interval: 0.840-0.955, p < 0.001; hazard ratio: 2.710, 95% confidence interval: 1.079-6.804, p: 0.03, respectively).

CONCLUSIONS

Individuals who have recovered from severe COVID-19 have shown an increased prevalence of aPwa. The existence of aPwa was not associated with the number of positive PCR tests for COVID-19 or the time elapsed after infection with COVID-19. Therefore, recovery from severe COVID-19 is an independent predictor of electrocardiographic abnormal P-wave axis.

Comparative Analysis of Lymphocyte Populations in Post-COVID-19 Condition and COVID-19 Convalescent Individuals

Reduced lymphocyte counts in peripheral blood are one of the most common observations in acute phases of viral infections. Although many studies have already examined the impact of immune (dys)regulation during SARS-CoV-2 infection, there are still uncertainties about the long-term consequences for lymphocyte homeostasis. Furthermore, as persistent cellular aberrations have been described following other viral infections, patients with "Post-COVID-19 Condition" (PCC) may present similarly. In order to investigate cellular changes in the adaptive immune system, we performed a retrospective analysis of flow cytometric data from lymphocyte subpopulations in 106 patients with confirmed SARS-CoV-2 infection who received medical care at our institution. The patients were divided into three groups according to the follow-up date; laboratory analyses of COVID-19 patients were compared with 28 unexposed healthy controls. Regarding B lymphocyte subsets, levels of IgA + CD27+, IgG + CD27+, IgM + CD27- and switched B cells were significantly reduced at the last follow-up compared to unexposed healthy controls (UHC). Of the 106 COVID-19 patients, 56 were clinically classified as featuring PCC. Significant differences between PCC and COVID-19 convalescents compared to UHC were observed in T helper cells and class-switched B cells. However, we did not detect specific or long-lasting immune cellular changes in PCC compared to the non-post-COVID-19 condition.

Meta-analysis of Cognitive Function Following Non-severe SARS-CoV-2 Infection

To effectively diagnose and treat subjective cognitive symptoms in post-acute sequalae of COVID-19 (PASC), it is important to understand objective cognitive impairment across the range of acute COVID-19 severity. Despite the importance of this area of research, to our knowledge, there are no current meta-analyses of objective cognitive functioning following non-severe initial SARS-CoV-2 infection. The aim of this meta-analysis is to describe objective cognitive impairment in individuals with non-severe (mild or moderate) SARS-CoV-2 cases in the post-acute stage of infection. This meta-analysis was pre-registered with Prospero (CRD42021293124) and utilized the PRISMA checklist for reporting guidelines, with screening conducted by at least two independent reviewers for all aspects of the screening and data extraction process. Fifty-nine articles (total participants = 22,060) with three types of study designs met our full criteria. Individuals with non-severe (mild/moderate) initial SARS-CoV-2 infection demonstrated worse objective cognitive performance compared to healthy comparison participants. However, those with mild (nonhospitalized) initial SARS-CoV-2 infections had better objective cognitive performance than those with moderate (hospitalized but not requiring ICU care) or severe (hospitalized with ICU care) initial SARS-CoV-2 infections. For studies that used normative data comparisons instead of healthy comparison participants, there was a small and nearly significant effect when compared to normative data. There were high levels of heterogeneity (88.6 to 97.3%), likely reflecting small sample sizes and variations in primary study methodology. Individuals who have recovered from non-severe cases of SARS-CoV-2 infections may be at risk for cognitive decline or impairment and may benefit from cognitive health interventions.

Reduced olfactory bulb volume accompanies olfactory dysfunction after mild SARS-CoV-2 infection

Despite its high prevalence, the determinants of smelling impairment in COVID-19 remain not fully understood. In this work, we aimed to examine the association between olfactory bulb volume and the clinical trajectory of COVID-19-related smelling impairment in a large-scale magnetic resonance imaging (MRI) analysis. Data of non-vaccinated COVID-19 convalescents recruited within the framework of the prospective Hamburg City Health Study COVID Program between March and December 2020 were analyzed. At baseline, 233 participants underwent MRI and neuropsychological testing as well as a structured questionnaire for olfactory function. Between March and April 2022, olfactory function was assessed at follow-up including quantitative olfactometric testing with Sniffin' Sticks. This study included 233 individuals recovered from mainly mild to moderate SARS-CoV-2 infections. Longitudinal assessment demonstrated a declining prevalence of self-reported olfactory dysfunction from 67.1% at acute infection, 21.0% at baseline examination and 17.5% at follow-up. Participants with post-acute self-reported olfactory dysfunction had a significantly lower olfactory bulb volume at baseline than normally smelling individuals. Olfactory bulb volume at baseline predicted olfactometric scores at follow-up. Performance in neuropsychological testing was not significantly associated with the olfactory bulb volume. Our work demonstrates an association of long-term self-reported smelling dysfunction and olfactory bulb integrity in a sample of individuals recovered from mainly mild to moderate COVID-19. Collectively, our results highlight olfactory bulb volume as a surrogate marker that may inform diagnosis and guide rehabilitation strategies in COVID-19.

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.

Epidemiologic Features of Recovery From SARS-CoV-2 Infection

Importance

Persistent symptoms and disability following SARS-CoV-2 infection, known as post-COVID-19 condition or "long COVID," are frequently reported and pose a substantial personal and societal burden.

Objective

To determine time to recovery following SARS-CoV-2 infection and identify factors associated with recovery by 90 days.

Design, Setting, and Participants

For this prospective cohort study, standardized ascertainment of SARS-CoV-2 infection was conducted starting in April 1, 2020, across 14 ongoing National Institutes of Health-funded cohorts that have enrolled and followed participants since 1971. This report includes data collected through February 28, 2023, on adults aged 18 years or older with self-reported SARS-CoV-2 infection.

Exposure

Preinfection health conditions and lifestyle factors assessed before and during the pandemic via prepandemic examinations and pandemic-era questionnaires.

Main Outcomes and Measures

Probability of nonrecovery by 90 days and restricted mean recovery times were estimated using Kaplan-Meier curves, and Cox proportional hazards regression was performed to assess multivariable-adjusted associations with recovery by 90 days.

Results

Of 4708 participants with self-reported SARS-CoV-2 infection (mean [SD] age, 61.3 [13.8] years; 2952 women [62.7%]), an estimated 22.5% (95% CI, 21.2%-23.7%) did not recover by 90 days post infection. Median (IQR) time to recovery was 20 (8-75) days. By 90 days post infection, there were significant differences in restricted mean recovery time according to sociodemographic, clinical, and lifestyle characteristics, particularly by acute infection severity (outpatient vs critical hospitalization, 32.9 days [95% CI, 31.9-33.9 days] vs 57.6 days [95% CI, 51.9-63.3 days]; log-rank P < .001). Recovery by 90 days post infection was associated with vaccination prior to infection (hazard ratio [HR], 1.30; 95% CI, 1.11-1.51) and infection during the sixth (Omicron variant) vs first wave (HR, 1.25; 95% CI, 1.06-1.49). These associations were mediated by reduced severity of acute infection (33.4% and 17.6%, respectively). Recovery was unfavorably associated with female sex (HR, 0.85; 95% CI, 0.79-0.92) and prepandemic clinical cardiovascular disease (HR, 0.84; 95% CI, 0.71-0.99). No significant multivariable-adjusted associations were observed for age, educational attainment, smoking history, obesity, diabetes, chronic kidney disease, asthma, chronic obstructive pulmonary disease, or elevated depressive symptoms. Results were similar for reinfections.

Conclusions and Relevance

In this cohort study, more than 1 in 5 adults did not recover within 3 months of SARS-CoV-2 infection. Recovery within 3 months was less likely in women and those with preexisting cardiovascular disease and more likely in those with COVID-19 vaccination or infection during the Omicron variant wave.

Youth Caregivers of Adults in the United States: Prevalence and the Association Between Caregiving and Education

A growing proportion of individuals adopt family caregiving roles. Family caregivers are the primary providers of long-term care in the United States yet limited federal policy supports exist, despite the known negative impacts of caregiving. There is also limited information about the prevalence of youth/young adult caregivers and the impacts of caregiving at formative ages in the United States. Our objective is to estimate the prevalence of youth caregivers and examine the association of caregiving with educational investments. We use the American Time Use Survey (2013-2019) to identify and describe youth caregivers (aged 15-18) and young adult caregivers (aged 19-22) and compare them with non-caregiving peers. We estimate that there are approximately 1,623,000 youth caregivers and 1,986,000 young adult caregivers, corresponding to 9.2% and 12.7% of these age groups, respectively. However, there is a wide range in the estimated prevalence per year, from approximately 364,000 to 2.8 million youth caregivers and from 353,000 to 2.2 million young adult caregivers, depending on caregiver definition. Unlike adult caregivers, we find that young men and women were nearly equally likely to provide care. We also find that non-White individuals are disproportionately represented as youth caregivers. Compared with non-caregiving peers, both youth and young adult caregivers are less likely to be enrolled in school and, among those enrolled in school, spend significantly less time on educational activities. Considering the association of caregiving among youth/young adults and education, policies supporting youth and young adult caregivers are critical.

Three-year outcomes of post-acute sequelae of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes post-acute sequelae of coronavirus disease 2019 (COVID-19) (PASC) in many organ systems. Risks of these sequelae have been characterized up to 2 years after infection, but longer-term follow-up is limited. Here we built a cohort of 135,161 people with SARS-CoV-2 infection and 5,206,835 controls from the US Department of Veterans Affairs who were followed for 3 years to estimate risks of death and PASC. Among non-hospitalized individuals, the increased risk of death was no longer present after the first year of infection, and risk of incident PASC declined over the 3 years but still contributed 9.6 (95% confidence interval (CI): 0.4-18.7) disability-adjusted life years (DALYs) per 1,000 persons in the third year. Among hospitalized individuals, risk of death declined but remained significantly elevated in the third year after infection (incidence rate ratio: 1.29 (95% CI: 1.19-1.40)). Risk of incident PASC declined over the 3 years, but substantial residual risk remained in the third year, leading to 90.0 (95% CI: 55.2-124.8) DALYs per 1,000 persons. Altogether, our findings show reduction of risks over time, but the burden of mortality and health loss remains in the third year among hospitalized individuals.

Generation of a humanized mAce2 and a conditional hACE2 mouse models permissive to SARS-COV-2 infection

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) remains a public health concern and a subject of active research effort. Development of pre-clinical animal models is critical to study viral-host interaction, tissue tropism, disease mechanisms, therapeutic approaches, and long-term sequelae of infection. Here, we report two mouse models for studying SARS-CoV-2: A knock-in mAce2F83Y,H353K mouse that expresses a mouse-human hybrid form of the angiotensin-converting enzyme 2 (ACE2) receptor under the endogenous mouse Ace2 promoter, and a Rosa26 conditional knock-in mouse carrying the human ACE2 allele (Rosa26hACE2). Although the mAce2F83Y,H353K mice were susceptible to intranasal inoculation with SARS-CoV-2, they did not show gross phenotypic abnormalities. Next, we generated a Rosa26hACE2;CMV-Cre mouse line that ubiquitously expresses the human ACE2 receptor. By day 3 post infection with SARS-CoV-2, Rosa26hACE2;CMV-Cre mice showed significant weight loss, a variable degree of alveolar wall thickening and reduced survival rates. Viral load measurements confirmed inoculation in lung and brain tissues of infected Rosa26hACE2;CMV-Cre mice. The phenotypic spectrum displayed by our different mouse models translates to the broad range of clinical symptoms seen in the human patients and can serve as a resource for the community to model and explore both treatment strategies and long-term consequences of SARS-CoV-2 infection.

Persistent chest pain following COVID-19 infection - A scoping review

Persistent chest pain (PCP) following acute COVID-19 infection is a commonly reported symptom with an unclear etiology, making its management challenging. This scoping review aims to address the knowledge gap surrounding the characteristics of PCP following COVID-19, its causes, and potential treatments. This is a scoping review of 64 studies, including observational (prospective, retrospective, cross-sectional, case series, and case-control) and one quasi-experimental study, from databases including Embase, PubMed/MEDLINE, Cochrane CENTRAL, Google Scholar, Cochrane Database of Systematic Reviews, and Scopus. Studies on patients with PCP following mild, moderate, and severe COVID-19 infection were included. Studies with patients of any age, with chest pain that persisted following acute COVID-19 disease, irrespective of etiology or duration were included. A total of 35 studies reported PCP symptoms following COVID-19 (0.24%-76.6%) at an average follow-up of 3 months or longer, 12 studies at 1-3 months and 17 studies at less than 1-month follow-up or not specified. PCP was common following mild-severe COVID-19 infection, and etiology was mostly not reported. Fourteen studies proposed potential etiologies including endothelial dysfunction, cardiac ischemia, vasospasm, myocarditis, cardiac arrhythmia, pneumonia, pulmonary embolism, postural tachycardia syndrome, or noted cardiac MRI (cMRI) changes. Evaluation methods included common cardiopulmonary tests, as well as less common tests such as flow-mediated dilatation, cMRI, single-photon emission computed tomography myocardial perfusion imaging, and cardiopulmonary exercise testing. Only one study reported a specific treatment (sulodexide). PCP is a prevalent symptom following COVID-19 infection, with various proposed etiologies. Further research is needed to establish a better understanding of the causes and to develop targeted treatments for PCP following COVID-19.

Human umbilical cord-derived mesenchymal stem cell transplantation improves the long COVID

No effective treatments can ameliorate symptoms of long COVID patients. Our study assessed the safety and efficacy of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) in the treatment of long COVID patients. Ten long COVID patients were enrolled and received intravenous infusions of UC-MSCs on Days 0, 7, and 14. Adverse events and clinical symptoms were recorded, and chest-high-resolution CT (HRCT) images and laboratory parameters were analyzed. During UC-MSCs treatment and follow-up, we did not observe serious adverse events, the symptoms of long COVID patients were significantly relieved in a short time, especially sleep difficulty, depression or anxiety, memory issues, and so forth, and the lung lesions were also repaired. The routine laboratory parameters did not exhibit any significant abnormalities following UC-MSCs transplantation (UMSCT). The proportion of regulatory T cells gradually increased, but it was not statistically significant until 12 months. The proportion of naive B cells was elevated, while memory B cells, class-switched B-cells, and nonswitched B-cells decreased at 1 month after infusion. Additionally, we observed a transient elevation in circulating interleukin (IL)-6 after UMSCT, while tumor necrosis factor (TNF)-α, IL-17A, and IL-10 showed no significant changes. The levels of circulating immunoglobulin (Ig) M increased significantly at month 2, while IgA increased significantly at month 6. Furthermore, the SARS-CoV-2 IgG levels remained consistently high in all patients at Month 6, and there was no significant decrease during the subsequent 12-month follow-up. UMSCT was safe and tolerable in long COVID patients. It showed potential in alleviating long COVID symptoms and improving interstitial lung lesions.

Salivary biomarkers as pioneering indicators for diagnosis and severity stratification of pediatric long COVID

Introduction

Long COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC), manifests as persistent and often debilitating symptoms enduring well beyond the initial COVID-19 infection. This disease is especially worrying in children since it can seriously alter their development. Presently, a specific diagnostic test or definitive biomarker set for confirming long COVID is lacking, relying instead on the protracted presence of symptoms post-acute infection.

Methods

We measured the levels of 13 biomarkers in 105 saliva samples (49 from children with long COVID and 56 controls), and the Pearson correlation coefficient was used to analyse the correlations between the levels of the different salivary biomarkers. Multivariate logistic regression analyses were performed to determine which of the 13 analysed salivary biomarkers were useful to discriminate between children with long COVID and controls, as well as between children with mild and severe long COVID symptoms.

Results

Pediatric long COVID exhibited increased oxidant biomarkers and decreased antioxidant, immune response, and stress-related biomarkers. Correlation analyses unveiled distinct patterns between biomarkers in long COVID and controls. Notably, a multivariate logistic regression pinpointed TOS, ADA2, total proteins, and AOPP as pivotal variables, culminating in a remarkably accurate predictive model distinguishing long COVID from controls. Furthermore, total proteins and ADA1 were instrumental in discerning between mild and severe long COVID symptoms.

Discussion

This research sheds light on the potential clinical utility of salivary biomarkers in diagnosing and categorizing the severity of pediatric long COVID. It also lays the groundwork for future investigations aimed at unravelling the prognostic value of these biomarkers in predicting the trajectory of long COVID in affected individuals.

Risk of Post-Acute Sequelae of SARS-CoV-2 Infection (PASC) Among Patients with Type 2 Diabetes Mellitus on Anti-Hyperglycemic Medications

Background

Observed activity of metformin in reducing the risk of severe COVID-19 suggests a potential use of the anti-hyperglycemic in the prevention of post-acute sequelae of SARS-CoV-2 infection (PASC). We assessed the 3-month and 6-month risk of PASC among patients with type 2 diabetes mellitus (T2DM) comparing metformin users to sulfonylureas (SU) or dipeptidyl peptidase-4 inhibitors (DPP4i) users.

Methods

We used de-identified patient level electronic health record data from the National Covid Cohort Collaborative (N3C) between October 2021 and April 2023. Participants were adults ≥ 18 years with T2DM who had at least one outpatient healthcare encounter in health institutions in the United States prior to COVID-19 diagnosis. The outcome of PASC was defined based on the presence of a diagnosis code for the illness or using a predicted probability based on a machine learning algorithm. We estimated the 3-month and 6-month risk of PASC and calculated crude and weighted risk ratios (RR), risk differences (RD), and differences in mean predicted probability.

Results

We identified 5596 (mean age: 61.1 years; SD: 12.6) and 1451 (mean age: 64.9 years; SD 12.5) eligible prevalent users of metformin and SU/DPP4i respectively. We did not find a significant difference in risk of PASC at 3 months (RR = 0.86 [0.56; 1.32], RD = -3.06 per 1000 [-12.14; 6.01]), or at 6 months (RR = 0.81 [0.55; 1.20], RD = -4.91 per 1000 [-14.75, 4.93]) comparing prevalent users of metformin to prevalent users of SU/ DPP4i. Similar observations were made for the outcome definition using the ML algorithm.

Conclusion

The observed estimates in our study are consistent with a reduced risk of PASC among prevalent users of metformin, however the uncertainty of our confidence intervals warrants cautious interpretations of the results. A standardized clinical definition of PASC is warranted for thorough evaluation of the effectiveness of therapies under assessment for the prevention of PASC.

The causal role of gut microbiota in susceptibility of Long COVID: a Mendelian randomization study

Background

Long COVID is a major challenge facing the public. Gut microbiota is closely related to Long COVID. However, the causal effects between gut microbiota and Long COVID remains unclear.

Methods

Using summary statistics from Genome-Wide Association Studies (GWAS), Mendelian randomization (MR) analyses were performed to investigate the relationship between gut microbiota and Long COVID. The primary statistical method employed was Inverse Variance Weighted (IVW). Sensitivity analyses were then conducted to evaluate the reliability of the findings and account for potential confounding variables. Finally, a reverse MR analysis was conducted to examine potential associations between Long COVID and genetically predicted gut microbiota compositions.

Results

There were 2 positive and 1 negative causal effect between gut microbiota and Long COVID. Meta-analysis results show that genus Parasutterella (OR = 1.145, 95%CI = 1.035 ∼ 1.266, P = 0.008) and genus Oscillospira (OR = 1.425, 95%CI = 1.235 ∼ 1.645, P < 0.001) significantly increased the risk of Long COVID. And genus Eisenbergiella (OR = 0.861, 95%CI = 0.785 ∼ 0.943, P = 0.001) significantly decreased the risk of Long COVID. Neither the pleiotropy nor the heterogeneity was observed. Reverse causal effect does not hold.

Conclusion

Our research has provided genetic evidence that establishes multiple causal relationships between the gut microbiota and Long COVID, supporting the role of the gut microbiota in Long COVID. It is possible that different taxa play a role in the development of Long COVID. The causal relationships identified in this study require further investigation.

The possible mechanism and research progress of ACE2 involved in cardiovascular injury caused by COVID-19: a review

ACE2 is the earliest receptor discovered to mediate the entry of SARS-CoV-2. In addition to the receptor, it also participates in complex pathological and physiological processes, including regulating the RAS system, apelin, KKS system, and immune system. In addition to affecting the respiratory system, viral infections also interact with cardiovascular diseases. SARS-CoV-2 can directly invade the cardiovascular system through ACE2; Similarly, cardiovascular diseases such as hypertension and coronary heart disease can affect ACE2 levels and exacerbate the disease, and ACE2 dysregulation may also be a potential mechanism for long-term acute sequelae of COVID-19. Since the SARS CoV-2 epidemic, many large population studies have tried to clarify the current focus of debate, that is, whether we should give COVID-19 patients ACEI and ARB drug treatment, but there is still no conclusive conclusion. We also discussed potential disease treatment options for ACE2 at present. Finally, we discussed the researchers' latest findings on ACE2 and their prospects for future research.

Acute and Long COVID Intestinal Changes in an Experimental Model of Coronavirus in Mice

The COVID-19 pandemic, which emerged in early 2020, has had a profound and lasting impact on global health, resulting in over 7.0 million deaths and persistent challenges. In addition to acute concerns, there is growing attention being given to the long COVID health consequences for survivors of COVID-19 with documented cases of cardiovascular abnormalities, liver disturbances, lung complications, kidney issues, and noticeable cognitive deficits. Recent studies have investigated the physiological changes in various organs following prolonged exposure to murine hepatitis virus-1 (MHV-1), a coronavirus, in mouse models. One significant finding relates to the effects on the gastrointestinal tract, an area previously understudied regarding the long-lasting effects of COVID-19. This research sheds light on important observations in the intestines during both the acute and the prolonged phases following MHV-1 infection, which parallel specific changes seen in humans after exposure to SARS-CoV-2. Our study investigates the histopathological alterations in the small intestine following MHV-1 infection in murine models, revealing significant changes reminiscent of inflammatory bowel disease (IBD), celiac disease. Notable findings include mucosal inflammation, lymphoid hyperplasia, goblet cell hyperplasia, and immune cell infiltration, mirroring pathological features observed in IBD. Additionally, MHV-1 infection induces villous atrophy, altered epithelial integrity, and inflammatory responses akin to celiac disease and IBD. SPIKENET (SPK) treatment effectively mitigates intestinal damage caused by MHV-1 infection, restoring tissue architecture and ameliorating inflammatory responses. Furthermore, investigation into long COVID reveals intricate inflammatory profiles, highlighting the potential of SPK to modulate intestinal responses and restore tissue homeostasis. Understanding these histopathological alterations provides valuable insights into the pathogenesis of COVID-induced gastrointestinal complications and informs the development of targeted therapeutic strategies.

Risks of incident major osteoporotic fractures following SARS-CoV-2 infection among older individuals: a population-based cohort study in Hong Kong

Population-based epidemiological studies on post-acute phase coronavirus 2019 (COVID-19)-related fractures in older adults are lacking. This study aims to examine the risk of incident major osteoporotic fractures following SARS-CoV-2 infection among individuals aged ≥50, compared to individuals without COVID-19. It was a retrospective, propensity-score matched, population-based cohort study of COVID-19 patients and non-COVID individuals identified from the electronic database of the Hong Kong Hospital Authority from January 2020 to March 2022. The primary outcome was a composite of major osteoporotic fractures (hip, clinical vertebral, and upper limb). COVID-19 patients were 1:1 matched to controls using propensity-score according to age, sex, vaccination status, medical comorbidities and baseline medications. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models. A total of 429 459 COVID-19 patients were included, 1:1 matched to non-COVID individuals. Upon median follow-up of 11 months, COVID-19 patients had higher risks of major osteoporotic fractures (5.08 vs 3.95 per 1000 persons; HR 1.22 95%CI [1.15-1.31]), hip fractures (2.71 vs 1.94; 1.33 [1.22-1.46]), clinical vertebral fractures (0.42 vs 0.31; 1.29 [1.03-1.62]), and falls (13.83 vs 10.36; 1.28 [1.23-1.33]). Subgroup analyses revealed no significant interaction. In acute (within 30 days) and post-acute phases (beyond 30 days) following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we consistently observed a significant increase in fractures and falls risks. Our study demonstrated increased risk of major osteoporotic fractures after SARS-CoV-2 infection in both acute and post-acute phases in older adults, partly due to increased fall risk. Clinicians should be aware of musculoskeletal health of COVID-19 survivors.

Dizziness-related disability in persons with post-COVID condition: A cross sectional study

BACKGROUND

Dizziness is a common symptom in post-COVID condition (PCC) which may have a large impact on several life domains. However, knowledge on dizziness-severity and disability in PCC is sparse.

OBJECTIVE

The aim was to describe the severity of dizziness-related disability in individuals with PCC, and how it is manifested in daily life.

METHODS

A questionnaire regarding symptoms of PCC, health, and dizziness-related handicap was administered online, and 524 persons with PCC and dizziness were included.

RESULTS

Mean score of the Dizziness Handicap Inventory was 35.2 (24.0) and 51.8%, were classified as having moderate/severe dizziness-related disability. The percentage of maximum value for the subscales were: Physical manifestation, 48%, Emotional Impact, 36% and Catastrophic Impact, 17%. The greatest influence on physical movements was when bending forward, head shaking or doing strenuous physical activities or household chores.

CONCLUSIONS

Half had moderate or severe dizziness-related disability and the physical manifestations occurred mostly during specific or strenuous body movements. This indicate a vestibular impairment that may be effectively managed with vestibular rehabilitation. Assessment and treatment of dizziness might be an essential part in PCC rehabilitation and future research should continue to explore the potential causal pathways of dizziness in PCC.