Clinical characteristics of 310 SARS-CoV-2 Omicron variant patients and comparison with Delta and Beta variant patients in China

Enteral nutrition therapy for elderly patients with common-type COVID-19, a retrospective study based on medical records

BACKGROUND

The objective was to investigate the implications of enteral nutrition for elderly patients with common-type coronavirus disease 2019 (COVID-19).

METHODS

Data were retrospectively extracted from medical records. Enteral nutritional supplementation was recommended for patients with a nutritional risk score >3. The preferred method was oral administration, and preparations included Ensure and TPF-T. Continuous variables were compared using analysis of two-tailed Student's t-tests or one-way analysis of variance for normally distributed data and the rank sum test for non-normally distributed data. Categorical variables were compared using the χ2 test or Fisher's exact test. Values of p <0.05 were considered to be statistically significant.

RESULTS

The mortality rate in the whole cohort was 9.54%. A total of 474 patients tested negative and were discharged; among them, 173 patients received enteral nutrition while 301 patients did not. There were significant correlations between mortality and age, serum albumin concentration, prognostic nutritional index, underlying severe disease status and diet condition. In patients with a poor diet, early use of enteral nutrition is associated with faster conversion to a negative polymerase chain reaction test.

CONCLUSIONS

The prognosis of elderly patients with common-type COVID-19 was related to their nutritional status. Enteral nutritional supplementation is the preferred method of nutrition because it is the simplest and most widely accepted method for patients. For patients with poor diet conditions, enteral nutritional intervention should be performed early.

Characteristics of symptoms among outpatients following the discontinuation of the dynamic zero-COVID-19 policy in China: insights from an online nationwide cross-sectional survey in 2022

Background

After the cessation of the dynamic zero-coronavirus disease 2019 (COVID-19) policy in China, a large number of people were infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) without being hospitalized, but few studies investigated the symptoms of this population. In this study, we aimed to describe the symptom characteristics of this population and to provide information for further understanding of COVID-19.

Methods

An online nationwide anonymous survey questionnaire on symptoms was conducted through WeChat to probe participants infected with SARS-CoV-2 between December 2022 and January 2023. In order to guarantee the promptness of data collection while maximizing the coverage of diverse populations, we opted for the convenient sampling method. Demographic information, incidence and severity of main symptoms, and vaccination status were collected in the questionnaire. Descriptive analysis was utilized to elucidate the epidemiological characteristics of the overall population; comparative analysis was conducted to highlight the differences in symptom variations among distinct subgroups.

Results

A total of 4,836 valid questionnaires were collected, with 64.8% testing positive for COVID-19 and 35.2% exhibiting symptoms but not having undergone testing. Among the COVID-19-positive respondents, 64.3% (n=2,016) were female, with a median age of 39.0 (33.0, 47.0) years, and 95.8% (n=3,002) had received multiple vaccine doses. The prevalent comorbidities included allergic rhinitis (10.1%), hypertension (6.1%), and diabetes (3.5%). The most frequently reported symptoms were fever (n=2,941, 93.9%), fatigue (n=2,871, 91.6%), expectoration (n=2,847, 90.8%), nasal congestion (n=2,735, 87.2%), and myalgia (n=2,712, 86.5%). Vaccinated individuals, non-smokers, and males exhibited significantly higher rates of respiratory symptoms. Myalgia (35.3%), fatigue (31.5%), and sore throat (30.9%) were the symptoms with the highest incidence of severe occurrence, and this varied between age groups. Except for sneezing, age of 60 years or older was negatively correlated with severe manifestations for all symptoms. Conversely, smoking was positively associated with severe symptoms for nearly all conditions.

Conclusions

The study highlights common systemic and respiratory symptoms among non-hospitalized COVID-19 patients in China, varying by gender, age, and underlying diseases. These findings are clinically important for early identification, diagnosis, treatment evaluation, and global management of COVID-19.

Prevalence of infection and reinfection among health care workers in a hospital of Northern China between BA.5/BF.7 and XBB.1.5 wave

BACKGROUND

To analyze the epidemiological characteristics of the SARS-CoV-2 infection and reinfection associated with the emergence of Omicron variant in Healthcare workers (HCWs).

METHODS

We enrolled 760 HCWs who received 2-4 vaccination doses of COVID-19 and followed by BA.5/BF.7 and/or XBB.1.5 breakthrough infections between December 2022 and July 2023. Serum sample from each individual were collected approximately 1,3 and 6 months after last exposure. IgM, IgG and Total antibodies against SARS-CoV-2 were measured by chemiluminescent immunoassay. Meanwhile, we created an Enterprise WeChat link for HCWs to self-report SARS-CoV-2 infections, symptoms and post COVID-19 conditions.

RESULTS

Our study revealed that the reinfection rate among HCWs reached 26.1%. The main symptoms were fever (91.2% vs 60.1%), cough (78.8% vs 58.0%), and sore throat (75.4% vs 59.6%) during infection and reinfection in Omicron BA.5/BF.7 and XBB.1.5 wave, and the interval for reinfection ranged from 91 to 210 days (median 152). Fatigue (23.6%), memory loss (18.8%) and coughing (18.6%) were the most prevalent long COVID symptoms, with a higher prevalence among female HCWs.

CONCLUSIONS

HCWs reinfection with SARS-CoV-2 causes milder symptoms, but high reinfection rate and short intervals. Strengthen infection prevention and control is crucial to mitigating infection risk and improving health services.

Changes in Clinical Features and Severity of COVID-19 with the Emergence of Omicron Variants: A Shift Towards a Common Disease

Background

The emergence of the Omicron variant of severe acute respiratory syndrome coronavirus-2 has significantly altered the clinical features and severity of coronavirus disease 2019 (COVID-19).

Objective

This study aims to evaluate whether the clinical factors that previously predicted COVID-19 remain valid following the emergence of the Omicron variant.

Methods

This cross-sectional study was conducted at Showa University Fujigaoka Hospital from April 2022 to March 2023. A total of 576 patients with suspected COVID-19 were included, of which 258 (44.8%) were diagnosed with COVID-19 based on real-time reverse-transcription polymerase chain reaction tests. Clinical data were collected retrospectively, and multivariate logistic regression was used to analyze factors associated with a COVID-19 diagnosis.

Results

Of the 258 patients diagnosed with COVID-19, 60% had mild disease, and the overall severity was lower than in previous reports prior to the emergence of the Omicron variant. In the multivariate analysis, only C-reactive protein (CRP) levels were significantly associated with COVID-19 (odds ratio, 0.3164; 95% confidence interval, 0.2077-0.4819), while factors such as age, sex, body mass index, lactate dehydrogenase, and comorbidities were not significantly associated. Non-COVID-19 cases were primarily bacterial infections, accounting for 57.2% of the non-COVID-19 diagnoses. Mortality rates did not differ significantly between the COVID-19 and non-COVID-19 groups.

Conclusion

The clinical characteristics of COVID-19 have become less distinct since the emergence of the Omicron variant, with CRP being the primary marker associated with a COVID-19 diagnosis. As COVID-19 continues to transition towards a more common infectious disease, distinguishing it will become increasingly challenging.

A Comparative Study of Clinical Characteristics and COVID-19 Vaccine Effectiveness Against SARS-CoV-2 Variants: Wild-Type, Alpha, Delta, and Omicron in Beijing, China

Background

To compare the clinical characteristics of symptoms and laboratory findings across SARS-CoV-2 variants (Wild-type, Alpha, Delta, Omicron) and assess the effectiveness of COVID-19 vaccines in preventing symptoms and laboratory abnormalities.

Methods

We conducted a retrospective cohort study of individuals with SARS-CoV-2 infection at Beijing Ditan Hospital, Capital Medical University. Patients were grouped by the SARS-CoV-2 variant (Wild-type, Alpha, Delta, Omicron) based on whole-genome sequencing. Thirteen symptoms and 22 laboratory indices were compared across variants, and Omicron patients were further analyzed by vaccination status with generalized estimating equations (GEE) model.

Results

One thousand four hundred and thirteen participants were included for the analysis as following: Wild-type group (N=322), Alpha group (N=67), Delta group (N=98), and Omicron group (N=926). Omicron patients showed the highest proportion (30.1%) of respiratory symptoms across groups. Patients displayed normal laboratory manifestation, except for inflammatory markers, coagulation function index and glucose. Meanwhile, the Omicron variant was featured by higher inflammatory biomarkers (serum amyloid A protein [SAA] and C-reactive protein [CRP]). In addition, Omicron patients with three or more vaccine doses had fewer symptoms and higher values of SAA and CRP compared to those with fewer than three doses. Results of GEE showed, when compared with ≤ 1 vaccine dose, red blood cell count, white blood cell count, neutrophil count, platelet count, haemoglobin, and C-reactive protein in patients with ≥ 3 doses of vaccine significantly increased; while aspartic transaminase, creatine kinase, blood urea nitrogen, activated partial thromboplastin time, prothrombin time and thrombin time dramatically decreased, respectively.

Conclusion

Omicron variant resulted in abnormal inflammatory response. Individuals with three or more vaccine doses are more likely to experience fewer symptoms and have stronger protection against the virus. This study highlights key differences in symptom onset and laboratory profiles across SARS-CoV-2 variants, reinforcing the importance of three vaccine doses in providing strong protection against the Omicron variant.

Impact of preexisting digestive problems on the gastrointestinal symptoms of patients with omicron variant of SARS-CoV-2 infection

OBJECTIVE

This study focused on the gastrointestinal (GI) symptoms in the omicron variant infection and the related factors based on digestive health.

METHODS

A cross-sectional study was conducted on individuals infected with the omicron variant. A structured questionnaire was developed to gather their demographic characteristics, preexisting digestive problems (diseases & symptoms), and clinical manifestations during the infection.

RESULTS

11,484 questionnaires were received from online platforms. 7,929 infected participants were selected based on inclusion and exclusion criteria. Among them, 4,225 (53.3%) were females, and the mean age was 36.0±8.8 years old. In general, the proportion of GI symptoms in the omicron variant infection was 31.4% (62.6% and 25.0% in participants with pre-existing digestive problems and those without, respectively). The participants with pre-existing digestive problems exhibited more severe clinical manifestations during infection compared to those without. Notably, participants with gastrointestinal symptoms during the infection had more severe clinical manifestations, regardless of basic digestive health. Upper, rather than lower GI symptoms were more closely associated with the severity of the clinical manifestations. NSAIDs may increase the occurrence of GI symptoms in participants with a healthy digestive system but not in those with preexisting digestive problems.

CONCLUSION

Patients infected with the omicron variant may experience more severe clinical symptoms if they have gastrointestinal issues. Digestive health strongly influences the occurrence of gastrointestinal symptoms and the severity of clinical manifestations.

Associations between clinical data, vaccination status, antibody responses, and post-COVID-19 symptoms in Thais infected with SARS-CoV-2 Delta and Omicron variants: a 1-year follow-up study

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), led to a global pandemic from 2020. In Thailand, five waves of outbreaks were recorded, with the fourth and fifth waves driven by the Delta and Omicron variants, resulting in over 20,000 new confirmed cases daily at their peaks.

METHODS

This cross-sectional study investigated the associations between clinical symptoms, vaccination status, antibody responses, and post-COVID-19 sequelae in COVID-19 patients. Plasma samples and clinical data were collected from participants admitted to hospitals in Thailand between July 2021 and August 2022, with follow-ups conducted for one year. The study included 110 participants infected with either the Delta (n = 46) or Omicron (n = 64) variants. Virus genotypes were confirmed by RT-PCR of nasal swab RNA and partial nucleotide sequencing of the S gene. IgG and IgA antibody levels against the receptor-binding domain (RBD) of SARS-CoV-2 Delta and Omicron variants were measured in plasma samples using ELISA.

RESULTS

Pneumonia was found to be associated with Delta variant infections, while sore throat, congestion or runny nose, and headache were linked to Omicron infections. Vaccination with fewer than two doses and diabetes mellitus were significantly associated with higher disease severity. Specific IgG and IgA antibodies against the RBD of the Delta variant generally rose by day 14 and were maintained for up to two months, whereas the pattern of antibody response to the Omicron variant was less clear. Antibody risings were found to be positively associated with pneumonia, certain underlying conditions (obesity, hypertension, dyslipidemia, and diabetes mellitus), and age ≥ 60 years. Delta variant infections were associated with forgetfulness, hair loss, and headache during the 1-year post-infection period. Females were more likely to experience hair loss, forgetfulness, and joint pain, while older age was associated with joint pain.

CONCLUSIONS

This study enhances our understanding of SARS-CoV-2 infections in Thais, particularly concerning the Delta and Omicron variants. The findings can inform public health planning and response strategies for future outbreaks of SARS-CoV-2 or other emerging viral diseases.

The Risk of Exacerbation of Myasthenia Gravis After COVID-19 Omicron Infection

OBJECTIVE

The aim of this study is to ascertain whether COVID-19 Omicron infection is associated with exacerbations in these myasthenia gravis (MG) patients.

RESULT

In total, 289 MG patients (comprising 60% females, with an average age of 46 ± 15 years) were enrolled. A total of 80.9% of MG patients reported a COVID-19 infection, with the majority experiencing a benign course (88%). MG patients who experienced COVID-19 infection demonstrated a higher likelihood of MG exacerbation, compared to those without the infection (18.8% vs. 7.3%, p = 0.039). In the survival analysis, after adjusting for confounding factors, the hazard ratio (HR) for exacerbation post-infection was found to be 3.38 (95% CI 1.20-9.53, p = 0.021). Compared to the exacerbation rates observed in JTA21, an increase was noted in DTM23 among COVID-19-infected MG patients (4.4% vs. 17.2%, p < 0.001).

CONCLUSION

The COVID-19 is the risk of MG exacerbation.

Differential immunometabolic responses to Delta and Omicron SARS-CoV-2 variants in golden syrian hamsters

Delta (B.1.617.2) and Omicron (B.1.1.529) variants of SARS-CoV-2 represents unique clinical characteristics. However, their role in altering immunometabolic regulations during acute infection remains convoluted. Here, we evaluated the differential immunopathogenesis of Delta vs. Omicron variants in Golden Syrian hamsters (GSH). The Delta variant resulted in higher virus titers in throat swabs and the lungs and exhibited higher lung damage with immune cell infiltration than the Omicron variant. The gene expression levels of immune mediators and metabolic enzymes, Arg-1 and IDO1 in the Delta-infected lungs were significantly higher compared to Omicron. Further, Delta/Omicron infection perturbed carbohydrates, amino acids, nucleotides, and TCA cycle metabolites and was differentially regulated compared to uninfected lungs. Collectively, our data provide a novel insight into immunometabolic/pathogenic outcomes for Delta vs. Omicron infection in the GSH displaying concordance with COVID-19 patients associated with inflammation and tissue injury during acute infection that offered possible new targets to develop potential therapeutics.

Optimal timing for awake prone positioning in Covid-19 patients: Insights from an observational study from two centers

BACKGROUND

The widespread application and interest in awake prone positioning stems from its ease and availability and its ability to enhance patients' oxygenation. Nevertheless, due to the absence of consensus over the regimen of awake prone positioning, the efficacy of awake prone positioning remains uncertain.

OBJECTIVE

To explore the optimal regimen for awake prone positioning, including the timing of initiation, ideal daily duration, and strategies for improving patient comfort and encouraging adherence.

DESIGN

Retrospective observational study.

SETTING(S)

Two university-affiliated hospitals in Shanghai.

PARTICIPANTS

Between December 2022 and February 2023, a total of 475 patients with COVID-19-related pneumonia who received awake prone positioning were observed.

METHODS

The data were collected from the hospital's electronic medical record system. The differentiation efficiency of peripheral blood oxygen saturation [SpO2]:fractional oxygen concentration in inspired air [FiO2] ratio at first awake prone positioning for different outcomes was tested by the area under the receiver operating characteristic curve. The Cox proportional hazard regression model was used to analyze the relationship between time to occurrence of 28-day outcomes and collected variables. Kaplan-Meier curves were plotted with the percentage of 28-day outcomes according to the SpO2:FiO2 ratio at first awake prone positioning after controlling covariates through Cox regression.

RESULTS

The best efficiency in predicting patient outcomes was achieved when the cutoff SpO2:FiO2 ratio at first awake prone positioning was 200. Patients with a reduced SpO2:FiO2 ratio (≤200) experienced more adverse respiratory outcomes (RR = 5.42, 95%CI [3.35, 8.76], p < 0·001) and higher mortality (RR = 16.64, 95%CI [5.53, 50.13], p < 0.001). Patients with a SpO2:FiO2 ratio of ≥200 at first awake prone positioning, longer duration between first awake prone positioning and admission, more awake prone positioning days, and better awake prone positioning completion were significantly protected from 28-day adverse respiratory outcomes and mortality.

CONCLUSIONS

Initiating awake prone positioning with a SpO2:FiO2 ratio exceeding 200, increasing the number of awake prone positioning days, prolonging the time between first awake prone positioning and admission, and achieving better completion of awake prone positioning were found to be significantly associated with reduced adverse respiratory outcomes and mortality.

REGISTRATION

ClinicalTrials.gov; No.: NCT05795751; URL: www.

CLINICALTRIALS

gov.

Molecular characterization of SARS-CoV-2 Omicron clade and clinical presentation in children

Since its emergence, SARS-CoV-2 Omicron clade has shown a marked degree of variability and different clinical presentation compared with previous clades. Here we demonstrate that at least four Omicron lineages circulated in children since December 2021, and studied until November 2022: BA.1 (33.6%), BA.2 (40.6%), BA.5 (23.7%) and BQ.1 (2.1%). At least 70% of infections concerned children under 1 year, most of them being infected with BA.2 lineages (n = 201, 75.6%). Looking at SARS-CoV-2 genetic variability, 69 SNPs were found to be significantly associated in pairs, (phi <  - 0.3 or > 0.3 and p-value < 0.001). 16 SNPs were involved in 4 distinct clusters (bootstrap > 0.75). One of these clusters (A23040G, A27259C, T23617G, T23620G) was also positively associated with moderate/severe COVID-19 presentation (AOR [95% CI] 2.49 [1.26-4.89] p-value: 0.008) together with comorbidities (AOR [95% CI] 2.67 [1.36-5.24] p-value: 0.004). Overall, these results highlight the extensive SARS-CoV-2 Omicron circulation in children, mostly aged < 1 year, and provide insights on viral diversification even considering low-abundant SNPs, finally suggesting the potential contribution of viral diversification in affecting disease severity.

Intestinal immunological events of acute and resolved SARS-CoV-2 infection in non-human primates

SARS-CoV-2 infection has been associated with intestinal mucosal barrier damage, leading to microbial and endotoxin translocation, heightened inflammatory responses, and aggravated disease outcomes. This study aimed to investigate the immunological mechanisms associated with impaired intestinal barrier function. We conducted a comprehensive analysis of gut damage and inflammation markers and phenotypic characterization of myeloid and lymphoid populations in the ileum and colon of SARS-CoV-2-exposed macaques during both the acute and resolved infection phases. Our findings revealed a significant accumulation of terminally differentiated and activated CD4+ and CD8+ T cells, along with memory B cells, within the gastrointestinal tract up to 43 days after exposure to SARS-CoV-2. This robust infection-induced immune response was accompanied by a notable depletion of plasmacytoid dendritic cells, myeloid dendritic cells, and macrophages, particularly affecting the colon during the resolved infection phase. Additionally, we identified a population of CX3CR1Low inflammatory macrophages associated with intestinal damage during active viral replication. Elevated levels of immune activation and gut damage markers, and perturbation of macrophage homeostasis, persisted even after the resolution of the infection, suggesting potential long-term clinical sequelae. These findings enhance our understanding of gastrointestinal immune pathology following SARS-CoV-2 infection and provide valuable information for developing and testing medical countermeasures.

Clinical characteristics and high risk factors of patients with Omicron variant strain infection in Hebei, China

Objective

The Omicron variant has a weaker pathogenicity compared to the Delta variant but is highly transmissible and elderly critically ill patients account for the majority. This study has significant implications for guiding clinical personalized treatment and effectively utilizing healthcare resources.

Methods

The study focuses on 157 patients infected with the novel coronavirus Omicron variant, from December, 2022, to February, 2023. The objective is to analyze the baseline data, test results, imaging findings and identify risk factors associated with severe illness.

Results

Among the 157 included patients, there were 55 cases in the non-severe group (all were moderate cases) and 102 cases in the severe group (including severe and critical cases). Infection with the Omicron variant exhibits significant differences between non-severe and severe cases (baseline data, blood routine, coagulation, inflammatory markers, cardiac, liver, kidney functions, Chest CT, VTE score, etc.). A multifactorial logistic regression analysis showed that neutrophil percentage >75%, eosinophil percentage <0.4%, D-dimer >0.55 mg/L, PCT >0.25 ng/mL, LDH >250 U/L, albumin <40 g/L, A/G ratio <1.2, cholinesterase<5100 U/L, uric acid >357 mole/L and blood calcium<2.11 mmol/L were the most likely independent risk factors for severe novel coronavirus infection.

Conclusion

Advanced age, low oxygenation index, elevated neutrophil percentage, decreased eosinophil percentage, elevated PCT, elevated LDH, decreased albumin, decreased A/G ratio, elevated uric acid, decreased blood calcium, and elevated D-dimer are independent prognostic risk factors for non-severe patients progressing to severe illness. These factors should be closely monitored and actively treated to prevent or minimize the occurrence of severe illness.

Characteristics and Prognostic Factors of SARS-CoV-2 Omicron Variant Infection in Hemodialysis Patients: A Single-Center Study in China

INTRODUCTION

This study aimed to evaluate the characteristics and prognostic factors for coronavirus disease 2019 (COVID-19) patients on maintenance hemodialysis (HD).

METHODS

All admitted HD patients who were infected with SARS-CoV-2 from December 1, 2022, to January 31, 2023, were included. Patients with pneumonia were further classified into the mild, moderate, severe, and critical illness. Clinical symptoms, laboratory results, radiologic findings, treatment, and clinical outcomes were collected. Independent risk factors for progression to critical disease and in-hospital mortality were determined by the multivariate regression analysis. The receiver operating characteristic analysis with the area under the curve was used to evaluate the predictive performance of developing critical status and in-hospital mortality.

RESULTS

A total of 182 COVID-19 patients with HD were included, with an average age of the 61.55 years. Out of the total, 84 (46.1%) patients did not have pneumonia and 98 (53.8%) patients had pneumonia. Among patients with pneumonia, 48 (49.0%) had moderate illness, 26 (26.5%) severe illness, and 24 (24.5%) critical illness, respectively. Elder age [HR (95% CI): 1.07 (1.01-1.13), p <0.01], increased levels of lactate dehydrogenase (LDH) [1.01 (1.003-1.01), p <0.01], and C-reactive protein (CRP) [1.01 (1.00-1.01), p = 0.04] were risk factors for developing critical illness. Elder age [1.11 (1.03-1.19), p = 0.01], increased procalcitonin (PCT) [1.07 (1.02-1.12), p = 0.01], and LDH level [1.004 (1-1.01), p = 0.03] were factors associated with increased risk of in-hospital mortality.

CONCLUSION

Age, CRP, PCT, and LDH can be used to predict negative clinical outcomes for HD patients with COVID-19 pneumonia.

Smell, taste and chemesthesis disorders in patients with the SARS-CoV-2 during Omicron variant pandemic in China

Chemosensory disorders (including smell, taste and chemesthesis) are among the established symptoms of COVID-19 infection; however, new data indicate that the changes in chemosensory sensation caused by COVID-19 may differ among populations and COVID-19 variants. To date, few studies have focused on the influence of the SARS-CoV-2 Omicron variant on qualitative changes and quantitative reductions in chemosensory function in China. We conducted a cross-sectional study of patients with COVID-19 caused by the Omicron variant, to investigate the prevalence of chemosensory disorders and chemosensory function before and during infection, using an online questionnaire. A total of 1245 patients with COVID-19 completed the survey. The prevalence rates of smell, taste, and chemesthesis disorders were 69.2%, 67.7%, and 31.4%, respectively. Our data indicate that sex, age, smoking, and COVID-19-related symptoms, such as lack of appetite, dyspnea, and fatigue, may be associated with chemosensory disorders during COVID-19. Self-rating of chemosensory function revealed that patients experienced a general decline in smell, taste, and chemesthesis function. Further longitudinal research studies are needed to generate additional data based on objective assessment and investigate the factors influencing chemosensory function in COVID-19.

Clinical symptom profile of hospitalized COVID-19 Brazilian patients according to SARS-CoV-2 variants

OBJECTIVES

The aim of this study was to investigate the prevalence of the main symptoms in Brazilian coronavirus disease 2019 (COVID-19) patients hospitalized during 4 distinct waves, based on their infection with different severe acute respiratory disease coronavirus 2 (SARS-CoV-2) variants.

METHODS

This study included hospitalized patients who tested positive for SARS-CoV-2 during 15 weeks around the peak of each of 4 waves: W1, ancestral strain/B.1 lineage (May 31 to September 12, 2020); W2, Gamma/P.1 variant (January 31 to May 15, 2021); W3, Omicron variant (December 5, 2021 to March 19, 2022); and W4, BA.4/BA.5 subvariants (May 22 to September 3, 2022). Symptom data were extracted from the Brazilian Severe Acute Respiratory Syndrome Database. Relative risks were calculated, and an analysis of symptom networks was performed.

RESULTS

Patients who were hospitalized during the prevalence of the Gamma/P.1 variant demonstrated a higher risk, primarily for symptoms such as fatigue, abdominal pain, low oxygen saturation, and sore throat, than patients hospitalized during the first wave. Conversely, patients who were hospitalized during the predominance of the Omicron variant exhibited a lower relative risk, particularly for symptoms such as loss of smell, loss of taste, diarrhea, fever, respiratory distress, and dyspnea. Similar results were observed in COVID-19 patients who were hospitalized during the wave of the Omicron subvariants BA.4/BA.5. A symptom network analysis, conducted to explore co-occurrence patterns among different variants, revealed significant differential profiles across the 4 waves, with the most notable difference observed between the W2 and W4 networks.

CONCLUSIONS

Overall, the relative risks and patterns of symptom co-occurrence associated with different SARS-CoV-2 variants may reflect disease severity.

SARS-CoV-2 Nsp8 induces mitophagy by damaging mitochondria

Autophagy plays an important role in the interaction between viruses and host cells. SARS-CoV-2 infection can disrupt the autophagy process in target cells. However, the precise molecular mechanism is still unknown. In this study, we discovered that the Nsp8 of SARS-CoV-2 could cause an increasing accumulation of autophagosomes by preventing the fusion of autophagosomes and lysosomes. From further investigation, we found that Nsp8 was present on mitochondria and can damage mitochondria to initiate mitophagy. The results of experiments with immunofluorescence revealed that Nsp8 induced incomplete mitophagy. Moreover, both domains of Nsp8 orchestrated their function during Nsp8-induced mitophagy, in which the N-terminal domain colocalized with mitochondria and the C-terminal domain induced auto/mitophagy. This novel finding expands our understanding of the function of Nsp8 in promoting mitochondrial damage and inducing incomplete mitophagy, which helps us to understand the etiology of COVID-19 as well as open up new pathways for creating SARS-CoV-2 treatment methods.

Risk of Thrombosis during and after a SARS-CoV-2 Infection: Pathogenesis, Diagnostic Approach, and Management

Coronavirus disease 2019 (COVID-19) increases the risk of thromboembolic events, especially in patients with severe infections requiring intensive care and cardiorespiratory support. COVID-19 patients with thromboembolic complications have a higher risk of death, and if they survive, these complications are expected to negatively affect these patients’ quality of life. Moreover, recent data reported that the risk of thromboembolism remains high months after a COVID-19 infection. Therefore, understanding the pathogenesis of thrombosis in the setting of COVID-19 may facilitate the early prevention and treatment of COVID-19-associated thromboembolism to reduce concomitant morbidity, mortality, and disability. This review will first discuss the clinical characteristics of COVID-19 infections, particularly with regard to the underlying pathophysiology. Then, the pathogenesis of COVID-19-associated thrombosis at the molecular and cellular levels will be comprehensively reviewed. Next, the clinical manifestations of venous and arterial thromboembolism in COVID-19 as well as the potential benefits of several laboratory markers of thrombosis will be further discussed. Lastly, the preventive and therapeutic management of thromboembolism during and after COVID-19 will also be explained.

Prevalence of Olfactory Dysfunction with the Omicron Variant of SARS-CoV-2: A Systematic Review and Meta-Analysis

The omicron variant is thought to cause less olfactory dysfunction than previous variants of SARS-CoV-2, but the reported prevalence differs greatly between populations and studies. Our systematic review and meta-analysis provide information regarding regional differences in prevalence as well as an estimate of the global prevalence of olfactory dysfunction based on 62 studies reporting information on 626,035 patients infected with the omicron variant. Our estimate of the omicron-induced prevalence of olfactory dysfunction in populations of European ancestry is 11.7%, while it is significantly lower in all other populations, ranging between 1.9% and 4.9%. When ethnic differences and population sizes are considered, the global prevalence of omicron-induced olfactory dysfunction in adults is estimated to be 3.7%. Omicron's effect on olfaction is twofold to tenfold lower than that of the alpha or delta variants according to previous meta-analyses and our analysis of studies that directly compared the prevalence of olfactory dysfunction between omicron and previous variants. The profile of the prevalence differences between ethnicities mirrors the results of a recent genome-wide association study that connected a gene locus encoding an odorant-metabolizing enzyme, UDP glycosyltransferase, to the extent of COVID-19-related loss of smell. Our analysis is consistent with the hypothesis that this enzyme contributes to the observed population differences.

Prevalence of Olfactory Dysfunction with the Omicron Variant of SARS-CoV-2: A Systematic Review and Meta-analysis

The omicron variant is thought to cause less olfactory dysfunction than previous variants of SARS-CoV-2, but the reported prevalence differs greatly between populations and studies. Our systematic review and meta-analysis provide information about regional differences in prevalence as well as an estimate of the global prevalence of olfactory dysfunction based on 62 studies reporting on 626,035 patients infected with the omicron variant. Our estimate of the omicron-induced prevalence of olfactory dysfunction in populations of European ancestry is 11.7%, while it is significantly lower in all other populations, ranging between 1.9% and 4.9%. When ethnic differences and population sizes are taken into account, the global prevalence of omicron-induced olfactory dysfunction in adults is estimated at 3.7%. Omicron’s effect on olfaction is twofold to tenfold lower than that of the alpha or delta variant, according to previous meta-analyses and our analysis of studies that directly compared prevalence of olfactory dysfunction between omicron and previous variants. The profile of prevalence differences between ethnicities mirrors the results of a recent genome-wide association study that implicated a gene locus encoding an odorant-metabolizing enzyme, UDP glycosyltransferase, to be linked to the extent of COVID-related loss of smell. Our analysis is consistent with the hypothesis that this enzyme contributes to the observed population differences.

The Rescue of the Romanian Health System by the Emergency Departments during the Fourth Wave of COVID-19 Pandemic

The COVID-19 pandemic has led to the confrontation of the health system with the need to identify solutions for providing medical care to a very large number of patients. The main objective of our study was to describe the measures taken to provide optimal medical care to patients who presented themselves in one of the large emergency hospitals of Romania in the fourth wave of the COVID-19 pandemic. Material and Methods: We conducted a retrospective, observational study on a group of 1417 patients. The statistical analysis was performed using R. Results: The average length of stay of patients in the emergency departments was approximately 2.6 h, increasing to up to 15 days in some more severe cases. For rapid antigen tests, the highest positivity rate for SARS-CoV-2 was identified in patients aged >75 years (53%). Among the identified risk factors associated with the need for mechanical ventilation were advanced age (α < 0.001) and lack of vaccination against SARS-CoV-2 (α < 0.001). Discussion and conclusions: A method of saving the Romanian health system in full hospital bed occupancy conditions in the wards proved to be the provision of medical care in emergency departments.