Comparative symptomatology of infection with SARS-CoV-2 variants Omicron (B.1.1.529) and Delta (B.1.617.2) from routine contact tracing data in England

Risk factors for COVID-19 transmission in England: a multilevel modelling study using routine contact tracing data

Contact tracing for COVID-19 in England operated from May 2020 to February 2022. The clinical, demographic and exposure information collected on cases and their contacts offered a unique opportunity to study secondary transmission. We aimed to quantify the relative impact of host factors and exposure settings on secondary COVID-19 transmission risk using 550,000 sampled transmission links between cases and their contacts. Links, or 'contact episodes', were established where a contact subsequently became a case, using an algorithm accounting for incubation period, setting, and contact date. A mixed-effects logistic regression model was used to estimate adjusted odds of transmission. Of sampled episodes, 8.7% resulted in secondary cases. Living with a case (71% episodes) was the most significant risk factor (aOR = 2.6, CI = 1.9-3.6). Other risk factors included unvaccinated status (aOR = 1.2, CI = 1.2-1.3), symptoms, and older age (66-79 years; aOR = 1.4, CI = 1.4-1.5). Whilst global COVID-19 strategies emphasized protection outside the home, including education, travel, and gathering restrictions, this study evidences the relative importance of household transmission. There is a need to reconsider the contribution of household transmission to future control strategies and the requirement for effective infection control within households.

Comparison of sinonasal symptoms in upper respiratory tract infections during the infectious diseases season of November 2023 to March 2024-a cross-sectional study

Introduction

Upper respiratory tract infections (URTIs) are among the most common reasons for patients consulting a general practitioner (GP) during the infectious diseases season, with viruses being the predominant cause. The COVID-19 pandemic has significantly impacted GPs' perception of these infections. The pandemic's progression, especially with the emergence of the Omicron variant, has complicated the diagnosis and treatment of URTIs, with evolving symptoms.

Aim

The aim of this study was to assess the differences in symptoms reported by patients with various infections, such as COVID-19, influenza, common cold, and post-viral rhinosinusitis, during the infectious diseases season of November 2023 to March 2024.

Materials and methods

The study was conducted in a primary health care clinic, providing care for a population of approximately 10,000 people, among adult patients presenting with URTI symptoms during the 2023/2024 infectious diseases season. Patients qualified for the study were swabbed for SARS-CoV-2, influenza A and B and respiratory syncytial virus (RSV) antigens. Symptoms were assessed with the use of a semi-structured questionnaire.

Results

Of the 1810 patients presenting with symptoms of URTIs, 276 patients were included in the study. Among patients with COVID-19, symptoms of nasal obstruction (p = 0.005) and nasal discharge (p = 0.001) were less common than in those with influenza or common cold. However, these nasal symptoms were significantly more frequent among patients with COVID-19 who had confirmed previous immunization (COVID-19 history or vaccination) (p = 0.028).

Conclusion

The incidence of individual sinonasal symptoms varies significantly depending on the aetiological agent of the URTI. This observation may not only help clinicians make the correct diagnosis, but also suggests an inflammatory response in the nasal mucosa and paranasal sinuses that is dependent on the aetiological agent. The study also indicates that this response is altered within the same virus species following immunization.

Limitations

The study's limitations include a small sample size (276 patients), focus on one season and one GP practice, and reliance on clinical signs and antigen tests. Nonetheless, the findings provide valuable insights. Further research with larger patient groups and extended follow-up periods is required to confirm these findings.

Predicting Deterioration from Wearable Sensor Data in People with Mild COVID-19

Coronavirus has caused many casualties and is still spreading. Some people experience rapid deterioration that is mild at first. The aim of this study is to develop a deterioration prediction model for mild COVID-19 patients during the isolation period. We collected vital signs from wearable devices and clinical questionnaires. The derivation cohort consisted of people diagnosed with COVID-19 between September and December 2021, and the external validation cohort collected between March and June 2022. To develop the model, a total of 50 participants wore the device for an average of 77 h. To evaluate the model, a total of 181 infected participants wore the device for an average of 65 h. We designed machine learning-based models that predict deterioration in patients with mild COVID-19. The prediction model, 10 min in advance, showed an area under the receiver characteristic curve (AUC) of 0.99, and the prediction model, 8 h in advance, showed an AUC of 0.84. We found that certain variables that are important to model vary depending on the point in time to predict. Efficient deterioration monitoring in many patients is possible by utilizing data collected from wearable sensors and symptom self-reports.

Changes in symptoms and characteristics of COVID-19 patients across different variants: two years study using neural network analysis

BACKGROUND

Considering the fact that COVID-19 has undergone various changes over time, its symptoms have also varied. The aim of this study is to describe and compare the changes in personal characteristics, symptoms, and underlying conditions of individuals infected with different strains of COVID-19.

METHODS

This descriptive-analytical study was conducted on 46,747 patients who underwent PCR testing during a two-year period from February 22, 2020 to February 23, 2022, in South Khorasan province, Iran. Patient characteristics and symptoms were extracted based on self-report and the information system. The data were analyzed using logistic regression and artificial neural network approaches. The R software was used for analysis and a significance level of 0.05 was considered for the tests.

RESULTS

Among the 46,747 cases analyzed, 23,239 (49.7%) were male, and the mean age was 51.48 ± 21.41 years. There was a significant difference in symptoms among different variants of the disease (p < 0.001). The factors with a significant positive association were myalgia (OR: 2.04; 95% CI, 1.76 - 2.36), cough (OR: 1.93; 95% CI, 1.68-2.22), and taste or smell disorder (OR: 2.62; 95% CI, 2.1 - 3.28). Additionally, aging was found to increase the likelihood of testing positive across the six periods.

CONCLUSION

We found that older age, myalgia, cough and taste/smell disorder are better factors compared to dyspnea or high body temperature, for identifying a COVID-19 patient. As the disease evolved, chills and diarrhea, demonstrated prognostic strength as in Omicron.

Effectiveness of kumquat decoction for the improvement of cough caused by SARS-CoV-2 Omicron variants, a multicentre, prospective observational study

BACKGROUND

Kumquat decoction is a traditional Chinese medicine formula and has been widely used to alleviate the coronavirus disease 2019 (COVID-19)-related cough in China. However, the effectiveness and safety of kumquat decoction remain unclear.

PURPOSE

To assess the effectiveness and safety of kumquat decoction for COVID-19-related cough.

STUDY DESIGN

A multicentre, prospective observational study.

METHODS

We enrolled consecutive patients with mild-to-moderate COVID-19 from December 31, 2022, to January 3, 2023, during the Omicron phase in Yangshuo County, China. The primary outcome was the time from study baseline to sustained cough resolution by the last follow-up day on January 31, 2023. The effectiveness was evaluated by Cox proportional hazards models based on propensity score analyses. The secondary outcomes were the resolution of cough and other COVID-19-related symptoms by Days 3, 5, and 7.

RESULTS

Of 1434 patients, 671 patients were excluded from the analysis of cough resolution. Among the remaining 763 patients, 481 (63.04%) received kumquat decoction, and 282 (36.96%) received usual care. The median age was 38.0 (interquartile range [IQR] 29.0, 50.0) years, and 55.7% were women. During a median follow-up of 7.000 days, 68.2% of patients in the kumquat group achieved sustained cough resolution (93.77 per 1000 person-days) compared to 39.7% in the usual care group (72.94 per 1000 person-days). The differences in restricted mean survival time (RMST) (kumquat decoction minus usual care group) for cough resolution were -0.742 days (95% CI, -1.235 to -0.250, P = 0.003) on Day 7. In the main analysis using propensity-score matching, the adjusted hazard ratio (HR) for cough resolution (kumquat decoction vs. usual care group) was 1.94 (95% CI, 1.48 to 2.53, P < 0.001). Similar findings were found in multiple sensitivity analyses. In addition, the use of kumquat decoction was associated with the resolution of cough, and a stuffy nose on Days 5 and 7, as well as the resolution of sore throat on Day 7 following medication.

CONCLUSION

In this study among patients with COVID-19-related cough, receiving kumquat decoction was associated with an earlier resolution of cough symptoms.

COVID-19-Associated Chemosensory Loss Continues to Decline

Chemosensory losses have long been considered a cardinal symptom of COVID-19 infection. Recent studies have shown changing symptom profiles with COVID-19, including decreasing incidence of olfactory losses. We accessed the National COVID Cohort Collaborative database to identify patients with and without smell and taste loss within 2 weeks of COVID-19 diagnosis. Peak prevalence time intervals for variants were determined from Covariants.org. Using rates of chemosensory loss during the peak time interval for "Untyped" variants as baseline (4/27/2020-6/18/2020), odds ratios for COVID-19-associated smell or taste disturbance fell for each of the Alpha (0.744), Delta (0.637), Omicron K (0.139), Omicron L (0.079), Omicron C (0.061), and Omicron B (0.070) peak intervals. These data suggest that during the recent Omicron waves and potentially moving forward, the presence or absence of smell and taste disturbances may no longer have predictive value in the diagnosis of COVID-19 infection.

Long COVID prevalence, risk factors and impact of vaccination in the paediatric population: A survey study in Singapore

Introduction

Information on the quality of health of children and younger persons (CYPs) after SARS-COV-2 infection remains scarce, especially from Asia. In this study, we utilised an online survey to investigate Long COVID prevalence in CYPs in Singapore.

Method

The study was an anonymised online survey of physical and functional symptoms, made available from 14 October 2022 to 15 January 2023. Caregivers of CYPs aged 0 to 18 years were invited to complete the survey on behalf of their CYPs. Participants provided demographic information and their history of SARS-CoV-2 infection status to allow classification into cases and controls for analysis.

Results

A total of 640 completed responses were analysed, 471 (73.6%) were cases and 169 (26.4%) were controls. The prevalence of Long COVID ≥3 months post-infection was 16.8%. This decreased to 8.7% ≥6 months post-infection. Cases had higher odds of developing Long COVID (odds ratio [OR] 2.42, 95% confidence interval [CI] 1.31-4.74). The most common symptoms of Long COVID were persistent cough (7.4%), nasal congestion (7.6%) and fatigue (3.0%). Male gender was significantly associated with higher odds of Long COVID (adjusted OR 1.71 [1.04-2.83]). Vaccinated CYPs had lower odds of Long COVID but this was not statically significant (adjusted OR 0.65, 95% CI 0.34-1.25).

Conclusion

About 1 in 6 CYPs in Singapore developed Long COVID with persistence of 1 or more symptoms ≥3 months post-infection, and approximately half will recover by 6 months. Male gender was associated with higher odds of Long COVID, and vaccination could potentially be protective against Long COVID in CYPs.

Evolution of SARS-CoV-2 Variants: Implications on Immune Escape, Vaccination, Therapeutic and Diagnostic Strategies

The COVID-19 pandemic caused by SARS-CoV-2 is associated with a lower fatality rate than its SARS and MERS counterparts. However, the rapid evolution of SARS-CoV-2 has given rise to multiple variants with varying pathogenicity and transmissibility, such as the Delta and Omicron variants. Individuals with advanced age or underlying comorbidities, including hypertension, diabetes and cardiovascular diseases, are at a higher risk of increased disease severity. Hence, this has resulted in an urgent need for the development of better therapeutic and preventive approaches. This review describes the origin and evolution of human coronaviruses, particularly SARS-CoV-2 and its variants as well as sub-variants. Risk factors that contribute to disease severity and the implications of co-infections are also considered. In addition, various antiviral strategies against COVID-19, including novel and repurposed antiviral drugs targeting viral and host proteins, as well as immunotherapeutic strategies, are discussed. We critically evaluate strategies of current and emerging vaccines against SARS-CoV-2 and their efficacy, including immune evasion by new variants and sub-variants. The impact of SARS-CoV-2 evolution on COVID-19 diagnostic testing is also examined. Collectively, global research and public health authorities, along with all sectors of society, need to better prepare against upcoming variants and future coronavirus outbreaks.

Pathogenesis and progression of anosmia and dysgeusia during the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is the causative agent of COVID-19 which was detected in late 2019 in Wuhan, China. As of September 2022, there have been over 612 million confirmed cases of COVID-19 with over 6.5 million associated deaths. In many cases, anosmia and dysgeusia have been identified as primary symptoms of COVID-19 infection in patients. While the loss of smell (anosmia) and loss of taste (dysgeusia) due to COVID-19 infection is transient in most patients, many report that these symptoms persist following recovery. Understanding the pathogenesis of these symptoms is paramount to early treatment of the infection. We conducted a literature review of Google Scholar and PubMed to find and analyze studies discussing anosmia and dysgeusia in the context of COVID-19 to understand the progression and management of these symptoms. The mechanism for dysgeusia is largely unknown; however, pathogenesis of anosmia includes inflammation and cytokine release resulting from the infection that alters neuronal signaling, thus inducing the loss of smell that patients experience. Anosmia may be managed and potentially resolved sooner with a combination therapy of olfactory training and budesonide irrigation of the nasal cavity. It is important to note that the variants of SARS-CoV-2 are genetically distinguished from the original virion due to a mutation in their spike proteins, giving them a different symptom profile regarding anosmia and dysgeusia. This variability in symptomatology is an area of study that needs to be further explored.

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.