The chronification of post-COVID condition associated with neurocognitive symptoms, functional impairment and increased healthcare utilization

Definitions and symptoms of the post-COVID syndrome: an updated systematic umbrella review

Post-COVID syndrome (PCS) describes a persistent complex of symptoms following a COVID-19 episode, lasting at least 4 to 12 weeks, depending on the specific criteria used for its definition. It is often associated with moderate to severe impairments of daily life and represents a major burden for many people worldwide. However, especially during the first two years of the COVID-19 pandemic, therapeutic and diagnostic uncertainties were prominent due to the novelty of the disease and non-specific definitions that overlooked functional deficits and lacked objective assessment. The present work comprehensively examines the status of PCS definitions as depicted in recent reviews and meta-analyses, alongside exploring associated symptoms and functional impairments. We searched the database Pubmed for reviews and meta-analysis evaluating PCS in the period between May 31, 2022, to December 31, 2023. Out of 95 studies, 33 were selected for inclusion in our analyses. Furthermore, we extended upon prior research by systematically recording the symptoms linked with PCS as identified in the studies. We found that fatigue, neurological complaints, and exercise intolerance were the most frequently reported symptoms. In conclusion, over the past eighteen months, there has been a notable increase in quantity and quality of research studies on PCS. However, there still remains a clear need for improvement, particularly with regard to the definition of the symptoms necessary for diagnosing this syndrome. Enhancing this aspect will render future research more comparable and precise, thereby advancing and understanding PCS.

Discovery of a new long COVID mouse model via systemic histopathological comparison of SARS-CoV-2 intranasal and inhalation infection

Intranasal infection is commonly used to establish a SARS-CoV-2 mouse model due to its non-invasive procedures and a minimal effect from the operation itself. However, mice intranasally infected with SARS-CoV-2 have a high mortality rate, which limits the utility of this model for exploring therapeutic strategies and the sequelae of non-fatal COVID-19 cases. To resolve these limitations, an aerosolised viral administration method has been suggested. However, an in-depth pathological analysis comparing the two models is lacking. Here, we show that inhalation and intranasal SARS-CoV-2 (106 PFU) infection models established in K18-hACE2 mice develop unique pathological features in both the respiratory and central nervous systems, which could be directly attributed to the infection method. While the inhalation-infection model exhibited relatively milder pathological parameters, it closely mimicked the prevalent chest CT pattern observed in COVID-19 patients with focal, peripheral lesions and fibrotic scarring in the recuperating lung. We also found the evidence of direct neuron-invasion from the olfactory receptor neurons to the olfactory bulb in the intranasal model and showed the trigeminal nerve as an alternative route of transmission to the brain in inhalation infected mice. Even after viral clearance confirmed at 14 days post-infection, mild lesions were still found in the brain of inhalation-infected mice. These findings suggest that the inhalation-infection model has advantages over the intranasal-infection model in closely mimicking the pathological features of non-fatal symptoms of COVID-19, demonstrating its potential to study the sequelae and possible interventions for long COVID.

Illness presentation and quality of life in myalgic encephalomyelitis/chronic fatigue syndrome and post COVID-19 condition: a pilot Australian cross-sectional study

PURPOSE

Post COVID-19 Condition (PCC), being persistent COVID-19 symptoms, is reminiscent of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)-a chronic multi-systemic illness characterised by neurocognitive, autonomic, endocrinological and immunological disturbances. This novel cross-sectional investigation aims to: (1) compare symptoms among people with ME/CFS (pwME/CFS) and people with PCC (pwPCC) to inform developing PCC diagnostic criteria; and (2) compare health outcomes between patients and people without acute or chronic illness (controls) to highlight the illness burdens of ME/CFS and PCC.

METHODS

Sociodemographic and health outcome data were collected from n = 61 pwME/CFS, n = 31 pwPCC and n = 54 controls via validated, self-administered questionnaires, including the 36-Item Short-Form Health Survey version 2 (SF-36v2) and World Health Organization Disability Assessment Schedule version 2.0 (WHODAS 2.0). PwME/CFS and pwPCC also provided self-reported severity and frequency of symptoms derived from the Canadian and International Consensus Criteria for ME/CFS and the World Health Organization case definition for PCC.

RESULTS

Both illness cohorts similarly experienced key ME/CFS symptoms. Few differences in symptoms were observed, with memory disturbances, muscle weakness, lymphadenopathy and nausea more prevalent, light-headedness more severe, unrefreshed sleep more frequent, and heart palpitations less frequent among pwME/CFS (all p < 0.05). The ME/CFS and PCC participants' SF-36v2 or WHODAS 2.0 scores were comparable (all p > 0.05); however, both cohorts returned significantly lower scores in all SF-36v2 and WHODAS 2.0 domains when compared with controls (all p < 0.001).

CONCLUSION

This Australian-first investigation demonstrates the congruent and debilitating nature of ME/CFS and PCC, thereby emphasising the need for multidisciplinary care to maximise patient health outcomes.

SARS-CoV-2 Infection and Postacute Risk of Non-Coronavirus Disease 2019 Infectious Disease Hospitalizations: A Nationwide Cohort Study of Danish Adults Aged ≥50 Years

BACKGROUND

Reports suggest that the potential long-lasting health consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may involve persistent dysregulation of some immune populations, but the potential clinical implications are unknown. We investigated the associated risk of hospitalization due to non-coronavirus disease 2019 (COVID-19) infectious diseases following the postacute phase of SARS-CoV-2 infection.

METHODS

By cross-linking data from the comprehensive Danish test and surveillance system for COVID-19 together with nationwide healthcare and demographic registers, we established a study cohort of 2 430 694 individuals aged ≥50 years, from 1 January 2021 to 10 December 2022, with no evidence of SARS-CoV-2 infection prior to study entry. Using Poisson regression, we compared the outcome rates of non-COVID-19 infectious disease hospitalizations following the acute phase of (a first) SARS-CoV-2 infection (defined as ≥29 days since the day of infection) in recovered individuals with rates among SARS-CoV-2-uninfected individuals.

RESULTS

Among 2 430 694 included individuals (mean age, 66.8 [standard deviation, 11.3] years), 930 071 acquired SARS-CoV-2 infection during follow-up totaling 4 519 913 person-years. The postacute phase of SARS-CoV-2 infection was associated with an incidence rate ratio (IRR) of 0.90 (95% confidence interval [CI]: .88-.92) for any infectious disease hospitalization. Findings (IRR [95% CI]) were similar for upper respiratory tract (1.08 [.97-1.20]), lower respiratory tract (0.90 [.87-.93]), influenza (1.04 [.94-1.15]), gastrointestinal (1.28 [.78-2.09]), skin (0.98 [.93-1.03]), urinary tract (1.01 [.96-1.08]), certain invasive bacterial (0.96 [.91-1.01]), and other (0.96 [.92-1.00]) infectious disease hospitalizations and in subgroups.

CONCLUSIONS

Our study does not support an increased susceptibility to non-COVID-19 infectious disease hospitalization following SARS-CoV-2 infection.

Exercise ventilatory response after COVID-19: comparison between ambulatory and hospitalized patients

Inefficient ventilatory response during cardiopulmonary exercise testing (CPET) has been suggested as a cause of post-COVID-19 dyspnea. It has been described in hospitalized patients (HOSP) with lung parenchymal sequelae but also after mild infection in ambulatory patients (AMBU). We hypothesize that AMBU and HOSP have different ventilatory responses to exercise, due to different etiologies. We analyzed CPET realized between July 2020 and May 2022 of patients with persisting respiratory symptoms 3 mo after COVID-19. Chest computed tomography (CT) scan, pulmonary function tests, quality of life, and respiratory questionnaires were collected. CPET data were specifically explored as a function of ventilation (V̇e) and time. Seventy-nine consecutive patients were included (42 AMBU and 37 HOSP, median: 54 [44-60] yr old, 57% female). Patients were hospitalized for a median of 20 [8-34] days, with pneumonia (41%) or acute respiratory distress syndrome (ARDS; 30%). Among HOSP, 12(32%) patients had abnormal values for spirometry and 18(51%) for carbon monoxide diffusing capacity (P < 0.001). CPET showed no differences between AMBU and HOSP in peak absolute O2 uptake (V̇o2) (1.59 [1.22-2.11] mL·min-1; P = 0.65). Tidal volume (VT) as a function of V̇e, was lower in AMBU than in HOSP (P < 0.01) toward the end of exercise. The slope of the V̇e-CO2 production was higher than normal in both groups (30.9 [26.1-34.3]; P = 0.96). In conclusion, the severity of COVID-19 did not influence the exercise capacity, but AMBU demonstrated a less efficient ventilatory response to exercise as compared with HOSP. CPET with exploration of data as a function of V̇e and throughout the exercise better unveil ventilatory inefficiency.NEW & NOTEWORTHY We evaluated the exercise ventilatory response in patients with persisting dyspnea after severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. We found that despite similar peak power and peak absolute O2 uptake, tidal volume as a function of ventilation was lower in ambulatory than in hospitalized patients toward the end of exercise, reflecting ventilatory inefficiency. We call for evaluation of minute ventilation with the exploration of data throughout the exercise and not only peak data to better unveil ventilatory inefficiency.

Correlations of Long COVID Symptoms and Inflammatory Markers of Complete Blood Count (CBC): A Cross-sectional Study

Background

Long-COVID refers to lasting unspecific symptoms like fatigue, decreased concentration and sleep issues after infection which persist for at least three months and cannot be attributed to other causes. Previous studies surveyed the association between inflammatory markers like C - reactive protein (CRP) at hospital admission and long-COVID symptoms in the preceding months. Post-COVID syndrome can affect one-third of patients. Thus early diagnosis can assist in reducing burdens on public health. We attempted to see any correlations between complete blood count (CBC) markers (like red blood cell (RBC), white blood cell (WBC), Neutrophil to lymphocyte ratio (NLR), etc.) at hospital admission and long COVID symptoms at a 6-month follow-up.

Methods

167 patients (44.9% females, mean age 49 years old) answered semi-structural interviews through telemedicine which focused on the three prominent symptoms: fatigue, loss of concentration and decreased libido. Results: Two third of patients have symptoms of long COVID and others do not have. NLR in the symptomatic group was statically higher. Patients who underwent decreased libido at a 6-month follow-up had significantly more severe lymphopenia (p = 0.028) and higher NLR values (p-value = 0.007). Poor mental concentration is associated with high WBC in numbers and polymorphonuclear (PMN) count. Other symptoms do not correlate with blood markers.

Conclusion

Utilizing available data like CBC can help predict the upcoming symptoms of previously hospitalized patients and further measures like rehabilitation. Additional investigations should be done on the effect of COVID vaccination on converting long COVID. Different variants of the virus may have different results.

Longitudinal Evaluation of an Integrated Post-COVID-19/Long COVID Management Program Consisting of Digital Interventions and Personal Support: Randomized Controlled Trial

BACKGROUND

The postacute COVID-19 syndrome (PACS) can be addressed with multidisciplinary approaches, including professional support and digital interventions.

OBJECTIVE

This research aimed to test whether patients who received a health care facilitation program including medical internet support from human personal pilots and digital interventions (intervention group [IG] and active control group [ACG]) would experience fewer symptoms and have higher work ability and social participation than an untreated comparison group (CompG). The second objective was to compare the impact of a diagnostic assessment and digital interventions tailored to patients' personal capacity (IG) with that of only personal support and digital interventions targeting the main symptoms (ACG).

METHODS

In total, 1020 patients with PACS were recruited. Using a randomized controlled trial design between the IG and the ACG, as well as propensity score matching to include the CompG, analyses were run with logistic regression and hierarchical-linear models.

RESULTS

Symptoms decreased significantly in all groups over time (βT1-T2=0.13, t549=5.67, P<.001; βT2-T4=0.06, t549=2.83, P=.01), with a main effect of the group (β=-.15, t549=-2.65, P=.01) and a more pronounced effect in the IG and ACG compared to the CompG (between groups: βT1-T2=0.14, t549=4.31, P<.001; βT2-T4=0.14, t549=4.57, P<.001). Work ability and social participation were lower in the CompG, but there was no significant interaction effect. There were no group differences between the IG and the ACG.

CONCLUSIONS

Empowerment through personal pilots and digital interventions reduces symptoms but does not increase work ability and social participation. More longitudinal research is needed to evaluate the effects of a diagnostic assessment. Social support and digital interventions should be incorporated to facilitate health care interventions for PACS.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05238415; https://classic.clinicaltrials.gov/ct2/show/NCT05238415.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1186/s12879-022-07584-z.

[S1 guidelines for the management of postviral conditions using the example of post-COVID-19]

These S1 guidelines are an updated and expanded version of the S1 guidelines on long COVID differential diagnostic and management strategies. They summarize the state of knowledge on postviral conditions like long/post COVID at the time of writing. Due to the dynamic nature of knowledge development, they are intended to be "living guidelines". The focus is on practical applicability at the level of primary care, which is understood to be the appropriate place for initial access and for primary care and treatment. The guidelines provide recommendations on the course of treatment, differential diagnostics of the most common symptoms that can result from infections like with SARS-CoV-2, treatment options, patient management and care, reintegration and rehabilitation. The guidelines have been developed through an interdisciplinary and interprofessional process and provide recommendations on interfaces and possibilities for collaboration.

Recovery and symptom trajectories up to two years after SARS-CoV-2 infection: population based, longitudinal cohort study

OBJECTIVE

To evaluate longer term symptoms and health outcomes associated with post-covid-19 condition within a cohort of individuals with a SARS-CoV-2 infection.

DESIGN

Population based, longitudinal cohort.

SETTING

General population of canton of Zurich, Switzerland.

PARTICIPANTS

1106 adults with a confirmed SARS-CoV-2 infection who were not vaccinated before infection and 628 adults who did not have an infection.

MAIN OUTCOME MEASURES

Trajectories of self-reported health status and covid-19 related symptoms between months six, 12, 18, and 24 after infection and excess risk of symptoms at six months after infection compared with individuals who had no infection.

RESULTS

22.9% (95% confidence interval 20.4% to 25.6%) of individuals infected with SARS-CoV-2 did not fully recover by six months. The proportion of individuals who had an infection who reported not having recovered decreased to 18.5% (16.2% to 21.1%) at 12 months and 17.2% (14.0% to 20.8%) at 24 months after infection. When assessing changes in self-reported health status, most participants had continued recovery (68.4% (63.8% to 72.6%)) or had an overall improvement (13.5% (10.6% to 17.2%)) over time. Yet, 5.2% (3.5% to 7.7%) had a worsening in health status and 4.4% (2.9% to 6.7%) had alternating periods of recovery and health impairment. The point prevalence and severity of covid-19 related symptoms also decreased over time, with 18.1% (14.8% to 21.9%) reporting symptoms at 24 months. 8.9% (6.5% to 11.2%) of participants reported symptoms at all four follow-up time points, while in 12.5% (9.8% to 15.9%) symptoms were alternatingly absent and present. Symptom prevalence was higher among individuals who were infected compared with those who were not at six months (adjusted risk difference 17.0% (11.5% to 22.4%)). Excess risk (adjusted risk difference) for individual symptoms among those infected ranged from 2% to 10%, with the highest excess risks observed for altered taste or smell (9.8% (7.7% to 11.8%)), post-exertional malaise (9.4% (6.1% to 12.7%)), fatigue (5.4% (1.2% to 9.5%)), dyspnoea (7.8% (5.2% to 10.4%)), and reduced concentration (8.3% (6.0% to 10.7%)) and memory (5.7% (3.5% to 7.9%)).

CONCLUSIONS

Up to 18% of individuals who were not vaccinated before infection had post-covid-19 condition up to two years after infection, with evidence of excess symptom risk compared with controls. Effective interventions are needed to reduce the burden of post-covid-19 condition. Use of multiple outcome measures and consideration of the expected rates of recovery and heterogeneity in symptom trajectories are important in the design and interpretation of clinical trials.

REGISTRATIONS

ISRCTN18181860, .

Prevalence of Post-Coronavirus Disease Condition 12 Weeks After Omicron Infection Compared With Negative Controls and Association With Vaccination Status

BACKGROUND

Post-coronovirus disease (COVID) symptoms can persist several months after severe acute respiratory syndrome coronavirus 2 infection. Little is known, however, about the prevalence of post-COVID condition following infections from Omicron variants and how this varies according to vaccination status. This study evaluates the prevalence of symptoms and functional impairment 12 weeks after an infection by Omicron variants (BA.1 and BA.2) compared with negative controls tested during the same period.

METHODS

Outpatient individuals who tested positive or negative for COVID-19 infection between December 2021 and February 2022 at the Geneva University Hospitals were followed 12 weeks after their test date.

RESULTS

Overall, 11.7% of Omicron cases had symptoms 12 weeks after the infection compared with 10.4% of individuals who tested negative during the same period (P < .001), and symptoms were much less common in vaccinated versus nonvaccinated individuals with Omicron infection (9.7% vs 18.1%; P < .001). There were no significant differences in functional impairment at 12 weeks between Omicron cases and negative controls, even after adjusting for multiple potential confounders.

CONCLUSIONS

The differential prevalence of post-COVID symptoms and functional impairment attributed to Omicron BA.1 and BA.2 infection is low when compared with negative controls. Vaccination is associated with lower prevalence of post-COVID symptoms.

Association of Post-COVID-19 Condition Symptoms and Employment Status

Importance

Little is known about the functional correlates of post-COVID-19 condition (PCC), also known as long COVID, particularly the relevance of neurocognitive symptoms.

Objective

To characterize prevalence of unemployment among individuals who did, or did not, develop PCC after acute infection.

Design, Setting, and Participants

This survey study used data from 8 waves of a 50-state US nonprobability internet population-based survey of respondents aged 18 to 69 years conducted between February 2021 and July 2022.

Main Outcomes and Measures

The primary outcomes were self-reported current employment status and the presence of PCC, defined as report of continued symptoms at least 2 months beyond initial month of symptoms confirmed by a positive COVID-19 test.

Results

The cohort included 15 308 survey respondents with test-confirmed COVID-19 at least 2 months prior, of whom 2236 (14.6%) reported PCC symptoms, including 1027 of 2236 (45.9%) reporting either brain fog or impaired memory. The mean (SD) age was 38.8 (13.5) years; 9679 respondents (63.2%) identified as women and 10 720 (70.0%) were White. Overall, 1418 of 15 308 respondents (9.3%) reported being unemployed, including 276 of 2236 (12.3%) of those with PCC and 1142 of 13 071 (8.7%) of those without PCC; 8229 respondents (53.8%) worked full-time, including 1017 (45.5%) of those with PCC and 7212 (55.2%) without PCC. In survey-weighted regression models excluding retired respondents, the presence of PCC was associated with a lower likelihood of working full-time (odds ratio [OR], 0.71 [95% CI, 0.63-0.80]; adjusted OR, 0.84 [95% CI, 0.74-0.96]) and with a higher likelihood of being unemployed (OR, 1.45 [95% CI, 1.22-1.73]; adjusted OR, 1.23 [95% CI, 1.02-1.48]). The presence of any cognitive symptom was associated with lower likelihood of working full time (OR, 0.70 [95% CI, 0.56-0.88]; adjusted OR, 0.75 [95% CI, 0.59-0.84]).

Conclusions and Relevance

PCC was associated with a greater likelihood of unemployment and lesser likelihood of working full time in adjusted models. The presence of cognitive symptoms was associated with diminished likelihood of working full time. These results underscore the importance of developing strategies to treat and manage PCC symptoms.

The role of discrimination in the relation between COVID-19 sequelae, psychological distress, and work impairment in COVID-19 survivors

Perceived discrimination and work impairment are commonly observed in COVID-19 survivors, but their relationship has not been well understood. We aimed to evaluate the role of discrimination in the development of psychological distress and work impairment in COVID-19 survivors. From April 2020 to November 2021, 309 patients were recruited at two designated COVID-19 hospitals in Japan. Participants completed a standardized questionnaire including COVID-19 sequelae, psychological distress, impairments in work performance and perceived discrimination. The majority of participants (62.5%) experienced one or more COVID-19 sequelae. Psychological distress was observed in 36.9% and work impairment in 37.9%. In multivariate logistic regression analyses, COVID-19 sequelae and discrimination were associated with both psychological distress and work impairment. Mediation analysis demonstrated that the direct effect of sequelae on work impairment was non-significant after accounting for psychological distress, suggesting that the effect of sequelae on work impairment was mainly mediated through psychological distress. These findings were replicated in a subgroup analysis limited to patients with mild COVID-19. We conclude that discrimination plays an important role in the development of psychological distress and work impairment, and that both discrimination and psychological distress should be targets of intervention in COVID-19 survivors.