Variant-specific symptoms of COVID-19 in a study of 1,542,510 adults in England

COVID-19 booster vaccine uptake and reduced risks for long-COVID: A cross-sectional study of a U.S. adult population

Long-COVID (having symptoms lasting 3 months or longer post-infection) is an emerging public health concern, yet research on whether COVID-19 booster vaccines can mitigate this condition is limited. This study examined associations between booster uptake and long-COVID prevalence among U.S. adults. Data were analyzed from 8757 adults aged 18 years or older with a history of COVID-19 infection from the 2022 National Health Interview Survey. Weighted prevalence and logistic regression models examined relationships between self-reported COVID-19 booster vaccination status and long-COVID, adjusting for sociodemographics and health factors. 19.5 % reported experiencing long-COVID. Individuals receiving the COVID-19 booster vaccine had significantly lower adjusted odds of long-COVID (OR 0.75, 95 % CI 0.61-0.93) compared to unvaccinated individuals. Overall, these findings suggest that COVID-19 booster vaccination is associated with a reduced prevalence of long-COVID among the U.S. adult population, underscoring the importance of optimizing booster uptake to mitigate the long-term impacts of COVID-19.

Cognitive deficits and cortical volume loss in COVID-19-related hyposmia

BACKGROUND AND PURPOSE

Studies have found that up to 73% of COVID-19 patients experience hyposmia. It is unclear if the loss of smell in COVID-19 is due to damage to the peripheral or central mechanisms. This study aimed to explore the impacts of COVID-19-induced hyposmia on brain structure and cognitive functions.

METHODS

The study included 36 hyposmic (h-COV) and 21 normosmic (n-COV) participants who had recovered from mild COVID-19 infection, as well as 25 healthy controls (HCs). All participants underwent neurological examination, neuropsychiatric assessment and Sniffin' Sticks tests. High-resolution anatomical images were collected; olfactory bulb (OB) volume and cortical thickness were measured.

RESULTS

Addenbrooke's Cognitive Examination-Revised total and language sub-scores were slightly but significantly lower in the h-COV group compared to the HC group (p = 0.04 and p = 0.037). The h-COV group exhibited poorer performance in the Sniffin' Sticks test terms of discrimination score, identification score and the composite score compared to the n-COV and HC groups (p < 0.001, p = 0.001 and p = 0.002 respectively). A decrease in left and right OB volumes was observed in the h-COV group compared to the n-COV and HC groups (p = 0.003 and p = 0.006 respectively). The cortical thickness analysis revealed atrophy in the left lateral orbitofrontal cortex in the h-COV group compared to HCs. A significant low positive correlation of varying degrees was detected between discrimination and identification scores and both OB and left orbital sulci.

CONCLUSION

Temporary or permanent hyposmia after COVID-19 infection leads to atrophy in the OB and olfactory-related cortical structures and subtle cognitive problems in the long term.

New variants of COVID-19 (XBB.1.5 and XBB.1.16, the "Arcturus"): A review of highly questioned concerns, a brief comparison between different peaks in the COVID-19 pandemic, with a focused systematic review on expert recommendations for prevention, vaccination, and treatment measures in the general population and at-risk groups

INTRODUCTION

The COVID-19 pandemic has taken many forms and continues to evolve, now around the Omicron wave, raising concerns over the globe. With COVID-19 being declared no longer a "public health emergency of international concern (PHEIC)," the COVID pandemic is still far from over, as new Omicron subvariants of interest and concern have risen since January of 2023. Mainly with the XBB.1.5 and XBB.1.16 subvariants, the pandemic is still very much "alive" and "breathing."

METHODS

This review consists of five highly concerning questions about the current state of the COVID Omicron peak. We searched four main online databases to answer the first four questions. For the last one, we performed a systematic review of the literature, with keywords "Omicron," "Guidelines," and "Recommendations."

RESULTS

A total of 31 articles were included. The main symptoms of the current Omicron wave include a characteristically high fever, coughing, conjunctivitis (with itching eyes), sore throat, runny nose, congestion, fatigue, body ache, and headache. The median incubation period of the symptoms is shorter than the previous peaks. Vaccination against COVID can still be considered effective for the new subvariants.

CONCLUSION

Guidelines recommend continuation of personal protective measures, third and fourth dose boosters, along with administration of bivalent messenger RNA vaccine boosters. The consensus antiviral treatment is combination therapy using Nirmatrelvir and Ritonavir, and the consensus for pre-exposure prophylaxis is Tixagevimab and Cilgavimab combination. We hope the present paper raises awareness for the continuing presence of COVID and ways to lower the risks, especially for at-risk groups.

Association of pre-existing depression and anxiety with Omicron variant infection

Pre-existing psychiatric disorders were linked to an increased susceptibility to COVID-19 during the initial outbreak of the pandemic, while evidence during Omicron prevalence is lacking. Leveraging data from two prospective cohorts in China, we identified incident Omicron infections between January 2023 and April 2023. Participants with a self-reported history or self-rated symptoms of depression or anxiety before the Omicron pandemic were considered the exposed group, whereas the others were considered unexposed. We employed multivariate logistic regression models to examine the association of pre-existing depression or anxiety with the risk of any or severe Omicron infection indexed by medical interventions or severe symptoms. Further, we stratified the analyses by polygenic risk scores (PRSs) for COVID-19 and repeated the analyses using the UK Biobank data. We included 10,802 individuals from the Chinese cohorts (mean age = 51.1 years, 45.6% male), among whom 7841 (72.6%) were identified as cases of Omicron infection. No association was found between any pre-existing depression or anxiety and the overall risk of Omicron infection (odds ratio [OR] =1.04, 95% confidence interval [CI] 0.95-1.14). However, positive associations were noted for severe Omicron infection, either as infections requiring medical interventions (1.26, 1.02-1.54) or with severe symptoms (≥3: 1.73, 1.51-1.97). We obtained comparable estimates when stratified by COVID-19 PRS level. Additionally, using clustering method, we identified eight distinct symptom patterns and found associations between pre-existing depression or anxiety and the patterns characterized by multiple or complex severe symptoms including cough and taste and smell decline (ORs = 1.42-2.35). The results of the UK Biobank analyses corroborated findings of the Chinese cohorts. In conclusion, pre-existing depression and anxiety was not associated with the risk of Omicron infection overall but an elevated risk of severe Omicron infection, supporting the continued efforts on monitoring and possible early intervention in this high-risk population during Omicron prevalence.

Diagnostics for Public Health - Infectious Disease Surveillance and Control

AbstractAccurate diagnostics are critical in public health to ensure successful disease tracking, prevention, and control. Many of the same characteristics are desirable for diagnostic procedures in both medicine and public health: for example, low cost, high speed, low invasiveness, ease of use and interpretation, day-to-day consistency, and high accuracy. This review lays out five principles that are salient when the goal of diagnosis is to improve the overall health of a population rather than that of a particular patient, and it applies them in two important use cases: pandemic infectious disease and antimicrobial resistance.

The prevalence of feigning and concealment of Covid-19 infections in an international sample

We asked 463 participants from 21 countries whether they had feigned and/or concealed having a coronavirus infection during the pandemic period. 384 respondents (83%) reported having experienced a coronavirus infection. They were, on average, younger and reported more chronic health issues than participants who said they had never been infected. 65 (14%) admitted to having feigned the infection. Prevalence doubled (28%) when asked if they knew anyone who had feigned a coronavirus infection. Main motives for feigning were to stay at home and to obtain sick leave. As to having concealed a coronavirus infection, 56 (12%) responded affirmatively, but when asked about others, the prevalence reached 51% (n = 210). The most common reasons for concealment were to avoid letting others know and to not miss an event. Thus, both feigning and concealing infections can occur on a nontrivial scale, directly affecting prevalence rates in studies that rely on self-reported data collected from social platforms.

Histochemical Evidence for Reduced Immune Response in Nasal Mucosa of Patients with COVID-19

The primary entry point of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the nasal mucosa, where viral-induced inflammation occurs. When the immune response fails against SARS-CoV-2, understanding the altered response becomes crucial. This study aimed to compare SARS-CoV-2 immunological responses in the olfactory and respiratory mucosa by focusing on epithelia and nerves. Between 2020 and 2022, we obtained post mortem tissues from the olfactory cleft from 10 patients with histologically intact olfactory epithelia (OE) who died with or from COVID-19, along with four age-matched controls. These tissues were subjected to immunohistochemical reactions using antibodies against T cell antigens CD3, CD8, CD68, and SARS spike protein for viral evidence. Deceased patients with COVID-19 exhibited peripheral lymphopenia accompanied by a local decrease in CD3+ cells in the OE. However, SARS-CoV-2 spike protein was sparsely detectable in the OE. With regard to the involvement of nerve fibers, the present analysis suggested that SARS-CoV-2 did not significantly alter the immune response in olfactory or trigeminal fibers. On the other hand, SARS spike protein was detectable in both nerves. In summary, the post mortem investigation demonstrated a decreased T cell response in patients with COVID-19 and signs of SARS-CoV-2 presence in olfactory and trigeminal fibers.

Using SCENTinel® to predict SARS-CoV-2 infection: insights from a community sample during dominance of Delta and Omicron variants

Introduction

Based on a large body of previous research suggesting that smell loss was a predictor of COVID-19, we investigated the ability of SCENTinel®, a newly validated rapid olfactory test that assesses odor detection, intensity, and identification, to predict SARS-CoV-2 infection in a community sample.

Methods

Between April 5, 2021, and July 5, 2022, 1,979 individuals took one SCENTinel® test, completed at least one physician-ordered SARS-CoV-2 PCR test, and endorsed a list of self-reported symptoms.

Results

Among the of SCENTinel® subtests, the self-rated odor intensity score, especially when dichotomized using a previously established threshold, was the strongest predictor of SARS-CoV-2 infection. SCENTinel® had high specificity and negative predictive value, indicating that those who passed SCENTinel® likely did not have a SARS-CoV-2 infection. Predictability of the SCENTinel® performance was stronger when the SARS-CoV-2 Delta variant was dominant rather than when the SARS-CoV-2 Omicron variant was dominant. Additionally, SCENTinel® predicted SARS-CoV-2 positivity better than using a self-reported symptom checklist alone.

Discussion

These results indicate that SCENTinel® is a rapid assessment tool that can be used for population-level screening to monitor abrupt changes in olfactory function, and to evaluate spread of viral infections like SARS-CoV-2 that often have smell loss as a symptom.

The changing clinical presentation of COVID-19 in children during the course of the pandemic

AIM

To investigate the evolution of clinical symptoms of COVID-19 in children throughout the pandemic.

METHODS

In this national prospective surveillance study, symptoms in children hospitalised with COVID-19 were collected from all paediatric hospitals in Switzerland between March 2020 and March 2023. Data was analysed across four time periods, according to the predominantly circulating SARS-CoV-2 variant: T1 (wild-type), T2 (Alpha), T3 (Delta) and T4 (Omicron), as well as by age group.

RESULTS

The study included 1323 children. The proportion of children admitted to an intensive care unit remained stable throughout the pandemic. However, the pattern and frequency of clinical manifestations changed over time. Respiratory symptoms were less prevalent during T1 (wild-type), fever during T2 (Alpha) and rash during T4 (Omicron). In contrast, fever and neurological symptoms were more prevalent during T4 (Omicron). Newly described symptoms during T4 (Omicron) included conjunctivitis, laryngotracheitis and seizures. Fever was more prevalent among neonates and infants whereas respiratory symptoms were more common among infants. Gastrointestinal symptoms were more frequent among toddlers, while both toddlers and school-aged children presented with neurological symptoms more often than other age groups.

CONCLUSION

Continuous surveillance is required to detect changes in manifestations and there by be prepared for the optimal management of complications in children with COVID-19.

Outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 in a Rural Community Hospital during Omicron Predominance

Healthcare-associated infections due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has increased since the discovery of the Omicron variant. We describe a SARS-CoV-2 outbreak in the medicine-surgery unit of a rural community hospital at the time of high community transmission of Omicron variant in our county. The outbreak occurred in the medicine-surgery unit of an 89-bed rural community hospital in northern Maine. The characteristics of the patients and healthcare workers (HCWs) affected by the outbreak are described. Patient and HCW data collected as part of the outbreak investigation were used in this report. The outbreak control measures implemented are also described. A total of 24 people tested positive for SARS-CoV-2 including 11 patients and 13 HCWs. A total of 12 of the 24 (50%) persons were symptomatic, and rhinorrhea was the most common symptom noted (8/12, 67%). None of the symptomatic persons had gastrointestinal symptoms or symptoms of a loss of sense of smell or taste. All HCWs were vaccinated and 8 of the 11 patients were vaccinated. Outbreak control measures in the affected unit included implementation of full PPE (N95 respirators, eye protection, gowns and gloves) during all patient care, serial testing of employees and patients in the affected unit, cohorting positive patients, closing visitation and thorough environmental cleaning including use of ultraviolet (UV) light disinfection. This outbreak exemplifies the high transmissibility of the Omicron variant of SARS-CoV-2. The outbreak occurred despite a well-established infection control program. We noted that serial testing, use of N95 respirators during all patient care and UV disinfection were some of the measures that could be successful in outbreak control.

COVID-19 in non-hospitalised adults caused by either SARS-CoV-2 sub-variants Omicron BA.1, BA.2, BA.4/5 or Delta associates with similar illness duration, symptom severity and viral kinetics, irrespective of vaccination history

BACKGROUND

SARS-CoV-2 variant Omicron rapidly evolved over 2022, causing three waves of infection due to sub-variants BA.1, BA.2 and BA.4/5. We sought to characterise symptoms and viral loads over the course of COVID-19 infection with these sub-variants in otherwise-healthy, vaccinated, non-hospitalised adults, and compared data to infections with the preceding Delta variant of concern (VOC).

METHODS

In a prospective, observational cohort study, healthy vaccinated UK adults who reported a positive polymerase chain reaction (PCR) or lateral flow test, self-swabbed on alternate weekdays until day 10. We compared participant-reported symptoms and viral load trajectories between infections caused by VOCs Delta and Omicron (sub-variants BA.1, BA.2 or BA.4/5), and tested for relationships between vaccine dose, symptoms and PCR cycle threshold (Ct) as a proxy for viral load using Chi-squared (χ2) and Wilcoxon tests.

RESULTS

563 infection episodes were reported among 491 participants. Across infection episodes, there was little variation in symptom burden (4 [IQR 3-5] symptoms) and duration (8 [IQR 6-11] days). Whilst symptom profiles differed among infections caused by Delta compared to Omicron sub-variants, symptom profiles were similar between Omicron sub-variants. Anosmia was reported more frequently in Delta infections after 2 doses compared with Omicron sub-variant infections after 3 doses, for example: 42% (25/60) of participants with Delta infection compared to 9% (6/67) with Omicron BA.4/5 (χ2 P < 0.001; OR 7.3 [95% CI 2.7-19.4]). Fever was less common with Delta (20/60 participants; 33%) than Omicron BA.4/5 (39/67; 58%; χ2 P = 0.008; OR 0.4 [CI 0.2-0.7]). Amongst infections with an Omicron sub-variants, symptoms of coryza, fatigue, cough and myalgia predominated. Viral load trajectories and peaks did not differ between Delta, and Omicron, irrespective of symptom severity (including asymptomatic participants), VOC or vaccination status. PCR Ct values were negatively associated with time since vaccination in participants infected with BA.1 (β = -0.05 (CI -0.10-0.01); P = 0.031); however, this trend was not observed in BA.2 or BA.4/5 infections.

CONCLUSION

Our study emphasises both the changing symptom profile of COVID-19 infections in the Omicron era, and ongoing transmission risk of Omicron sub-variants in vaccinated adults.

TRIAL REGISTRATION

NCT04750356.

Clinical Manifestations of Infections with the Omicron Sub-Lineages BA.1, BA.2, and BA.5: A Retrospective Follow-Up Analysis of Public Health Data from Mecklenburg-Western Pomerania, Germany

The Omicron variants BA.1, BA.2, and BA.5 caused several waves of SARS-CoV-2 in Germany in 2022. In this comparative study, public health data on SARS-CoV-2 infections from Mecklenburg-Western Pomerania, Germany, between January and October 2022 were examined retrospectively using Pearson's chi-squared tests and Fisher's exact tests for testing for statistical significance. Compared to BA.5 infections, BA.1 and BA.2 infections affected younger individuals aged up to 19 years significantly more often, whereas BA.5 infections occurred significantly more frequently in patients between 40 and 59 years of age when compared to BA.1 and BA.2. Infections with all three variants predominantly caused flu-like symptoms; nevertheless, there were significant differences between the reported symptoms of BA.1, BA.2, and BA.5 infections. Especially, the symptoms of 'fever', 'severe feeling of sickness', 'loss of taste', and 'loss of smell' were significantly more often present in patients with BA.5 infections compared to BA.1 and BA.2 cases. Additionally, BA.2 and BA.5 cases reported significantly more often the symptoms of 'runny nose' and 'cough' than BA.1-infected cases. Our findings indicate remarkable differences in the clinical presentations among the sub-lineages, especially in BA.5 infections. Furthermore, the study demonstrates a powerful tool to link epidemiological data with genetic data in order to investigate their potential impact on public health.

Risk perception as a motivational resource during the COVID-19 pandemic: the role of vaccination status and emerging variants

BACKGROUND

People's perceived risk of being infected and having severe illness was conceived as a motivational source of adherence to behavioral measures during the COVID-19 crisis.

METHODS

We used online self-reported data, spanning 20 months of the COVID-19 crisis in Belgium (n = 221,791; 34.4% vaccinated; July 2020 - March 2022) to study the association between risk perception and motivation.

RESULTS

Both perceived infection probability and severity fluctuated across time as a function of the characteristics of emerging variants, with unvaccinated persons perceiving decreasingly less risk compared to vaccinated ones. Perceived severity (and not perceived probability) was the most critical predictor of autonomous motivation for adherence to health-protective measures, a pattern observed at both the between-day and between-person level among both vaccinated and unvaccinated individuals. An integrated process model further indicated that on days with higher hospitalization load, participants reported being more adherent because risk severity and autonomous motivation for adherence were more elevated on these days.

CONCLUSIONS

These findings suggest that risk severity served as a critical and dynamic resource for adherence to behavioral measures because it fostered greater autonomous regulation.

Virus-mediated cell fusion of SARS-CoV-2 variants

SARS-CoV-2 has the ability to form large multi-nucleated cells known as syncytia. Little is known about how syncytia affect the dynamics of the infection or severity of the disease. In this manuscript, we extend a mathematical model of cell-cell fusion assays to estimate both the syncytia formation rate and the average duration of the fusion phase for five strains of SARS-CoV-2. We find that the original Wuhan strain has the slowest rate of syncytia formation (6.4×10-4/h), but takes only 4.0 h to complete the fusion process, while the Alpha strain has the fastest rate of syncytia formation (0.36 /h), but takes 7.6 h to complete the fusion process. The Beta strain also has a fairly fast syncytia formation rate (9.7×10-2/h), and takes the longest to complete fusion (8.4 h). The D614G strain has a fairly slow syncytia formation rate (2.8×10-3/h), but completes fusion in 4.0 h. Finally, the Delta strain is in the middle with a syncytia formation rate of 3.2×10-2/h and a fusing time of 6.1 h. We note that for these SARS-CoV-2 strains, there appears to be a tradeoff between the ease of forming syncytia and the speed at which they complete the fusion process.

[Post-COVID patients with persistent chemosensory symptoms are rare in the general population]

OBJECTIVE

The prevalence of long-/post-COVID-associated chemosensory symptoms is reported in the literature to be significantly higher than clinical reality reflects.

METHODS

1. N= 4062 adults acutely infected with SARS-CoV-2 and their symptoms transmitted by the Jena health office to the Robert Koch Institute between March 2020 and September 2021 were evaluated. 2. Part of the same cohort (N = 909 of 4062) answered an extensive questionnaire at least 3 months after the start of the infection, including existing chemosensory post-COVID-associated complaints. 3. Fourteen post-COVID Jena patients with chemosensory symptoms who had become acutely infected during the same period were diagnosed, treated and advised in our ENT specialist outpatient clinic.

RESULTS

The prevalence of chemosensory symptoms at the onset of infection was 19% (600/3187). About every second written respondent of the formerly acutely infected (441/890) remembered chemosensory symptoms during their COVID-19 infection. Of these, around 38% (167/441) complained of persistent chemosensory post-COVID symptoms after an average of 14.5 months. Only 2.3% (14/600) of the previously acutely infected patients with chemosensory symptoms sought medical help in a special consultation. Quantitative chemosensory damage could only be objectified in half, i.e. 1.2% (7/600) of the total cohort.

CONCLUSIONS

Despite a high prevalence of subjective chemosensory symptoms in acutely and formerly SARS-CoV-2 infected people, there is only a low need for specialized treatment, so that, unlike other post-COVID-associated complaints, the healthcare system as a whole appears to be less significantly burdened.

Identification of differences in the magnitude and specificity of SARS-CoV-2 nucleocapsid antibody responses in naturally infected and vaccinated individuals

As there are limited data on B-cell epitopes for the nucleocapsid protein in SARS-CoV-2, we sought to identify the immunodominant regions within the N protein, recognized by patients with varying severity of natural infection with the Wuhan strain (WT), delta, omicron, and in those who received the Sinopharm vaccines, which is an inactivated, whole virus vaccine. Using overlapping peptides representing the N protein, with an in-house ELISA, we mapped the immunodominant regions within the N protein, in seronegative (n = 30), WT infected (n = 30), delta infected (n = 30), omicron infected + vaccinated (n = 20) and Sinopharm (BBIBP-CorV) vaccinees (n = 30). We then investigated the sensitivity and specificity of these immunodominant regions and analyzed their conservation with other SARS-CoV-2 variants of concern, seasonal human coronaviruses, and bat Sarbecoviruses. We identified four immunodominant regions aa 29-52, aa 155-178, aa 274-297, and aa 365-388, which were highly conserved within SARS-CoV-2 and the bat coronaviruses. The magnitude of responses to these regions varied based on the infecting SARS-CoV-2 variants, >80% of individuals gave responses above the positive cut-off threshold to many of the four regions, with some differences with individuals who were infected with different VoCs. These regions were found to be 100% specific, as none of the seronegative individuals gave any responses. As these regions were highly specific with high sensitivity, they have a potential to be used to develop diagnostic assays and to be used in development of vaccines.

Vaccine Effectiveness against SARS-CoV-2 Infection during the Circulation of Alpha, Delta, or Omicron Variants: A Retrospective Cohort Study in a Tertiary Hospital in Serbia

The COVID-19 pandemic prompted rapid vaccine development and deployment worldwide. Despite widespread vaccination efforts, understanding the effectiveness of vaccines in hospitalized patients remains a critical concern. This retrospective cohort study, conducted at a tertiary healthcare centre in Serbia, tracked patients hospitalized during different waves of COVID-19 variants-Alpha, Delta, and Omicron. Data collection included demographics, comorbidities, symptoms, and vaccination status. Among 3593 patients, those with prior exposure to COVID-19 cases or hospital treatment showed higher positivity rates. Symptom prevalence varied across waves, with coughs persisting. Patients without chronic diseases were more frequent among those testing negative. Vaccine effectiveness varied, with Sinopharm demonstrating a 45.6% effectiveness initially and Pfizer-BioNTech showing an effectiveness of up to 74.8% within 0-84 days after the second dose. Mixed-dose strategies, notably Sinopharm as a primary dose followed by a Pfizer-BioNTech booster, suggested increased protection. Despite substantial vaccination availability, a significant portion of hospitalized patients remained unvaccinated. This study underscores the dynamic nature of vaccine effectiveness and advocates for booster strategies to address evolving challenges in combating COVID-19, particularly in hospitalized patients.

Limitations of the Cough Sound-Based COVID-19 Diagnosis Artificial Intelligence Model and its Future Direction: Longitudinal Observation Study

BACKGROUND

The outbreak of SARS-CoV-2 in 2019 has necessitated the rapid and accurate detection of COVID-19 to manage patients effectively and implement public health measures. Artificial intelligence (AI) models analyzing cough sounds have emerged as promising tools for large-scale screening and early identification of potential cases.

OBJECTIVE

This study aimed to investigate the efficacy of using cough sounds as a diagnostic tool for COVID-19, considering the unique acoustic features that differentiate positive and negative cases. We investigated whether an AI model trained on cough sound recordings from specific periods, especially the early stages of the COVID-19 pandemic, were applicable to the ongoing situation with persistent variants.

METHODS

We used cough sound recordings from 3 data sets (Cambridge, Coswara, and Virufy) representing different stages of the pandemic and variants. Our AI model was trained using the Cambridge data set with subsequent evaluation against all data sets. The performance was analyzed based on the area under the receiver operating curve (AUC) across different data measurement periods and COVID-19 variants.

RESULTS

The AI model demonstrated a high AUC when tested with the Cambridge data set, indicative of its initial effectiveness. However, the performance varied significantly with other data sets, particularly in detecting later variants such as Delta and Omicron, with a marked decline in AUC observed for the latter. These results highlight the challenges in maintaining the efficacy of AI models against the backdrop of an evolving virus.

CONCLUSIONS

While AI models analyzing cough sounds offer a promising noninvasive and rapid screening method for COVID-19, their effectiveness is challenged by the emergence of new virus variants. Ongoing research and adaptations in AI methodologies are crucial to address these limitations. The adaptability of AI models to evolve with the virus underscores their potential as a foundational technology for not only the current pandemic but also future outbreaks, contributing to a more agile and resilient global health infrastructure.

Comparative analysis of symptom profile and risk of death associated with infection by SARS-CoV-2 and its variants in Hong Kong

The recurrent multiwave nature of coronavirus disease 2019 (COVID-19) necessitates updating its symptomatology. We characterize the effect of variants on symptom presentation, identify the symptoms predictive and protective of death, and quantify the effect of vaccination on symptom development. With the COVID-19 cases reported up to August 25, 2022 in Hong Kong, an iterative multitier text-matching algorithm was developed to identify symptoms from free text. Multivariate regression was used to measure associations between variants, symptom development, death, and vaccination status. A least absolute shrinkage and selection operator technique was used to identify a parsimonious set of symptoms jointly associated with death. Overall, 70.9% (54 450/76 762) of cases were symptomatic with 102 symptoms identified. Intrinsically, the wild-type and delta variant caused similar symptoms among unvaccinated symptomatic cases, whereas the wild-type and omicron BA.2 subvariant had heterogeneous patterns, with seven symptoms (fatigue, fever, chest pain, runny nose, sputum production, nausea/vomiting, and sore throat) more frequent in the BA.2 cohort. With ≥2 vaccine doses, BA.2 was more likely than delta to cause fever among symptomatic cases. Fever, blocked nose, pneumonia, and shortness of breath remained jointly predictive of death among unvaccinated symptomatic elderly in the wild-type-to-omicron transition. Number of vaccine doses required for reducing occurrence varied by symptoms. We substantiate that omicron has a different clinical presentation compared to previous variants. Syndromic surveillance can be bettered with reduced reliance on symptom-based case identification, increased weighing on symptoms predictive of death in outcome prediction, individual-based risk assessment in care homes, and incorporating free-text symptom reporting.

Employee investigation and contact tracing program in a pediatric cancer hospital to mitigate the spread of COVID-19 among the workforce, patients, and caregivers

Background

Case investigations and contact tracing are essential disease control measures used by health departments. Early in the pandemic, they were seen as a key strategy to stop COVID-19 spread. The CDC urged rapid action to scale up and train a large workforce and collaborate across public and private agencies to halt COVID-19 transmission.

Methods

We developed a program for case investigation and contact tracing that followed CDC and local health guidelines, compliant with the Occupational Safety and Health Administration (OSHA) regulations and tailored to the needs and resources of our institution. Program staff were trained and assessed for competency before joining the program.

Results

From March 2020 to May 2021, we performed 838 COVID-19 case investigations, which led to 136 contacts. Most employees reported a known SARS-CoV-2 exposure from the community (n = 435) or household (n = 343). Only seven (5.1%) employees were determined as more likely than not to have SARS-CoV-2 infection related to workplace exposure, and when so, lapses in following the masking recommendations were identified. Between June 2021-February 2022, our program adjusted to the demand of the different waves, particularly omicron, by significantly reducing the amount of data collected. No transmission from employees to patients or caregivers was observed during this period.

Conclusion

Prompt implementation of case investigation and contact tracing is possible, and it effectively reduces workplace exposures. This approach can be adapted to suit the specific needs and requirements of various healthcare settings, particularly those serving the most vulnerable patient populations.

Extracting symptoms from free-text responses using ChatGPT among COVID-19 cases in Hong Kong

OBJECTIVES

To investigate the feasibility and performance of Chat Generative Pretrained Transformer (ChatGPT) in converting symptom narratives into structured symptom labels.

METHODS

We extracted symptoms from 300 deidentified symptom narratives of COVID-19 patients by a computer-based matching algorithm (the standard), and prompt engineering in ChatGPT. Common symptoms were those with a prevalence >10% according to the standard, and similarly less common symptoms were those with a prevalence of 2-10%. The precision of ChatGPT was compared with the standard using sensitivity and specificity with 95% exact binomial CIs (95% binCIs). In ChatGPT, we prompted without examples (zero-shot prompting) and with examples (few-shot prompting).

RESULTS

In zero-shot prompting, GPT-4 achieved high specificity (0.947 [95% binCI: 0.894-0.978]-1.000 [95% binCI: 0.965-0.988, 1.000]) for all symptoms, high sensitivity for common symptoms (0.853 [95% binCI: 0.689-0.950]-1.000 [95% binCI: 0.951-1.000]), and moderate sensitivity for less common symptoms (0.200 [95% binCI: 0.043-0.481]-1.000 [95% binCI: 0.590-0.815, 1.000]). Few-shot prompting increased the sensitivity and specificity. GPT-4 outperformed GPT-3.5 in response accuracy and consistent labelling.

DISCUSSION

This work substantiates ChatGPT's role as a research tool in medical fields. Its performance in converting symptom narratives to structured symptom labels was encouraging, saving time and effort in compiling the task-specific training data. It potentially accelerates free-text data compilation and synthesis in future disease outbreaks and improves the accuracy of symptom checkers. Focused prompt training addressing ambiguous descriptions impacts medical research positively.

SARS-CoV-2 infection in immunosuppression evolves sub-lineages which independently accumulate neutralization escape mutations

One mechanism of variant formation may be evolution during long-term infection in immunosuppressed people. To understand the viral phenotypes evolved during such infection, we tested SARS-CoV-2 viruses evolved from an ancestral B.1 lineage infection lasting over 190 days post-diagnosis in an advanced HIV disease immunosuppressed individual. Sequence and phylogenetic analysis showed two evolving sub-lineages, with the second sub-lineage replacing the first sub-lineage in a seeming evolutionary sweep. Each sub-lineage independently evolved escape from neutralizing antibodies. The most evolved virus for the first sub-lineage (isolated day 34) and the second sub-lineage (isolated day 190) showed similar escape from ancestral SARS-CoV-2 and Delta-variant infection elicited neutralizing immunity despite having no spike mutations in common relative to the B.1 lineage. The day 190 isolate also evolved higher cell-cell fusion and faster viral replication and caused more cell death relative to virus isolated soon after diagnosis, though cell death was similar to day 34 first sub-lineage virus. These data show that SARS-CoV-2 strains in prolonged infection in a single individual can follow independent evolutionary trajectories which lead to neutralization escape and other changes in viral properties.

Evaluating the accessibility and capacity of SARS-CoV-2 vaccination and analyzing convenience-related factors during the Omicron variant epidemic in Beijing, China

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination service system lacks standardized indicators to assess resource allocation. Moreover, data on specific vaccination-promoting measures is limited. This study aimed to evaluate vaccination accessibility and capacity and investigate convenience-related factors in China during the Omicron variant epidemic. We collected information on SARS-CoV-2 vaccination services among vaccination sites in Beijing. Analysis was performed using nearest neighbor, Ripley's K, hot spot analysis, and generalized estimating equations. Overall, 299 vaccination sites were included. The demand for the SARS-CoV-2 vaccine increased with the increase in daily new cases, and the number of staff administering vaccines should be increased in urban areas at the beginning of the epidemic. Providing vaccination for both children and adults, extending vaccination service hours, and offering a wider range of vaccine categories significantly increased the doses of vaccines administered (all P < .05). The provision of mobile vaccination vehicles effectively increased the doses of vaccines administered to individuals aged ≥ 60 years (P < .05). The allocation of SARS-CoV-2 vaccination services should be adjusted according to geographic location, population size, and vaccination demands. Simultaneous provision of vaccination services for children and their guardians, flexible service hours, prompt innovative vaccine production, and tailored vaccination strategies can foster vaccination uptake.

Oxygen Therapy During Activities of Daily Living Rehabilitation and Outcome in Patients With Severe-to-critical COVID-19

Objective

To primarily study the duration of supplemental oxygen use while performing ADLs (activities of daily living) and associations leading to a more prolonged oxygen therapy during these tasks. Secondary objectives include (1) studying the presence of COVID-19 related complications during inpatient rehabilitation and after discharge and (2) describing functional outcomes of participants after supplemental oxygen liberation and hospital discharge.

Design

Explorative prospective observational cohort study.

Setting

Rehabilitation center within a tertiary hospital, caring for post-COVID patients.

Participants

Twenty-three (N=23) community-dwelling persons with severe-to-critical COVID-19 disease and ongoing oxygen therapy needs. There was a preponderance of men (69.6%), with mean age of 69.5 (range 46-85) years.

Interventions

Inpatient pulmonary rehabilitation.

Main Outcome Measures

The primary outcome was the duration of supplemental oxygen use (from initiation till wean) for ambulation, toileting, dressing, and showering. Secondary outcomes included the presence of COVID-19 related complications (during rehabilitation and after discharge) and post-discharge functional status.

Results

After rehabilitation center transfer, all subjects only required oxygen therapy during task(s) performance, and not at rest. ADLs that took the shortest and longest time for supplemental oxygen weaning were dressing (mean 38.4±SD 17.1 days) and showering (mean 47.7±SD 18.1 days), respectively. The mean duration of oxygen therapy application was 48.6±SD 18.3 days. On multivariable analysis, mechanical ventilation and exertional desaturation were significantly associated with prolonged duration for oxygen therapy in all ADLs.

Conclusion

The duration of needful oxygen therapy was dissimilar for different ADLs. Showering, which required the longest duration of supplemental oxygen wean, might prove to be the rate-limiting ADL for discharge home.

A Danish questionnaire study of acute symptoms of SARS-CoV-2 infection by variant, vaccination status, sex and age

It is not well-described how the acute symptoms of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) differ by variant, vaccination, sex and age. A cross-sectional questionnaire study linked to national testing- and registry data was conducted among 148,874 SARS-CoV-2 first time reverse transcription polymerase chain reaction (RT-PCR) test-positive individuals and corresponding date-matched symptomatic test-negative controls. Major SARS-CoV-2 variants (Index/wild type, Alpha, Delta and Omicron) were defined using periods of predominance. Risk differences (RDs) were estimated for each of 21 predefined acute symptoms comparing: (1) test-positive and -negative individuals, by variant period, (2) vaccinated and unvaccinated test-positives, by variant period, (3) individuals tested positive during the Omicron and Delta periods, by vaccination status, and (4) vaccinated Omicron test-positive and -negative individuals, by age and sex. Compared to pre-Omicron, RDs between test-positive and test-negative individuals during the Omicron period were lower for most symptoms. RDs for altered sense of smell (dysosmia) and taste (dysgeusia) were highest for Delta (RD = 50.8 (49.4-52.0) and RD = 54.7 (53.4-56.0), respectively) and lowest for Omicron (RD = 12.8 (12.1-13.5) and RD = 11.8 (11.1-12.4), respectively). Across variants, vaccinated individuals reported fewer symptoms. During Omicron, females and 30-59 year-old participants reported more symptoms.

A multi-country analysis of COVID-19 hospitalizations by vaccination status

BACKGROUND

Individuals vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), when infected, can still develop disease that requires hospitalization. It remains unclear whether these patients differ from hospitalized unvaccinated patients with regard to presentation, coexisting comorbidities, and outcomes.

METHODS

Here, we use data from an international consortium to study this question and assess whether differences between these groups are context specific. Data from 83,163 hospitalized COVID-19 patients (34,843 vaccinated, 48,320 unvaccinated) from 38 countries were analyzed.

FINDINGS

While typical symptoms were more often reported in unvaccinated patients, comorbidities, including some associated with worse prognosis in previous studies, were more common in vaccinated patients. Considerable between-country variation in both in-hospital fatality risk and vaccinated-versus-unvaccinated difference in this outcome was observed.

CONCLUSIONS

These findings will inform allocation of healthcare resources in future surges as well as design of longer-term international studies to characterize changes in clinical profile of hospitalized COVID-19 patients related to vaccination history.

FUNDING

This work was made possible by the UK Foreign, Commonwealth and Development Office and Wellcome (215091/Z/18/Z, 222410/Z/21/Z, 225288/Z/22/Z, and 220757/Z/20/Z); the Bill & Melinda Gates Foundation (OPP1209135); and the philanthropic support of the donors to the University of Oxford's COVID-19 Research Response Fund (0009109). Additional funders are listed in the "acknowledgments" section.

[Persistent olfactory impairment after COVID-19-recommendations of the Working Group on Olfactology and Gustology of the German Society of Oto-rhino-laryngology, Head and Neck Surgery]

This article does not intend to comprehensively review the existing literature on coronavirus disease 2019 (COVID-19)-associated smell disorders, but aims to summarize scientific evidence for otorhinolaryngological practice and provide recommendations for diagnosis and treatment of persistent smell disorders following COVID-19.

Odds of COVID-19-associated asthma exacerbations in children higher during Omicron wave

BACKGROUND

We aimed to determine the association of COVID-19 variant wave with asthma exacerbations in children with asthma.

METHODS

We conducted a retrospective cross-sectional study of children in the Western Pennsylvania COVID-19 Registry (WPACR). We extracted data for all children in the WPACR with asthma and compared their acute clinical presentation and outcomes during the Pre-Delta (7/1/20-6/30/21), Delta (8/1/21-12/14/21), and Omicron (12/15/21-8/30/22) waves. We conducted multivariable logistic regression analyses of SARS-CoV-2-associated asthma exacerbations, adjusting for characteristics that have been associated with COVID-19 outcomes in prior studies.

RESULTS

Among 573 children with asthma in the WPACR during the study period, the proportion of children with COVID-19 who had an asthma exacerbation was higher during the Omicron wave than during the prior two variant waves (40.2% vs. 22.6% vs. 26.2%, p = 0.002; unadjusted OR = 2.12 [95% confidence interval (CI) = 1.39-3.22], p < 0.001). In our multivariable regression models, the odds of an asthma exacerbation were 2.8 times higher during the Omicron wave than during prior waves (adjusted OR = 2.80 [95% CI = 1.70-4.61]). Results were similar after additionally adjusting for asthma severity but were no longer significant after additionally adjusting for poor asthma control.

CONCLUSION

The proportion of children with asthma experiencing an asthma exacerbation during SARS-CoV-2 infection was higher during Omicron than prior variant waves, adding to the body of evidence that COVID-19-associated respiratory symptoms vary by variant. These findings provide additional support for vaccination and prevention.

Association of SARS-CoV-2 viral load with abnormal laboratory characteristics and clinical outcomes in hospitalised COVID-19 patients

We conducted a retrospective, analytical cross-sectional and single-centre study that included 190 hospitalised COVID-19 patients in the Fujian Provincial Hospital South Branch between December 2022 and January 2023 to analyse the correlation of viral loads of throat swabs with clinical progression and outcomes. To normalise the Ct value as quantification of viral loads, we used RNase P gene as internal control gene and subtracted the Ct value of SARS-CoV-2 N gene from the Ct value of RNase P gene, termed △Ct. Most patients were discharged (84.2%), and only 10 (5.6%) individuals who had a lower △Ct value died. The initial △Ct value of participants was also significantly correlated with some abnormal laboratory characteristics, and the duration time of SARS-CoV-2 was longer in patients with severe symptoms and a lower △Ct value at admission. Our study suggested that the △Ct value may be used as a predictor of disease progression and outcomes in hospitalised COVID-19 patients.

Meta-Analysis of COVID-19 Metabolomics Identifies Variations in Robustness of Biomarkers

The global COVID-19 pandemic resulted in widespread harms but also rapid advances in vaccine development, diagnostic testing, and treatment. As the disease moves to endemic status, the need to identify characteristic biomarkers of the disease for diagnostics or therapeutics has lessened, but lessons can still be learned to inform biomarker research in dealing with future pathogens. In this work, we test five sets of research-derived biomarkers against an independent targeted and quantitative Liquid Chromatography-Mass Spectrometry metabolomics dataset to evaluate how robustly these proposed panels would distinguish between COVID-19-positive and negative patients in a hospital setting. We further evaluate a crowdsourced panel comprising the COVID-19 metabolomics biomarkers most commonly mentioned in the literature between 2020 and 2023. The best-performing panel in the independent dataset-measured by F1 score (0.76) and AUROC (0.77)-included nine biomarkers: lactic acid, glutamate, aspartate, phenylalanine, β-alanine, ornithine, arachidonic acid, choline, and hypoxanthine. Panels comprising fewer metabolites performed less well, showing weaker statistical significance in the independent cohort than originally reported in their respective discovery studies. Whilst the studies reviewed here were small and may be subject to confounders, it is desirable that biomarker panels be resilient across cohorts if they are to find use in the clinic, highlighting the importance of assessing the robustness and reproducibility of metabolomics analyses in independent populations.

Early referring saved lives in kidney transplant recipients with COVID-19: a beneficial role of telemedicine

Introduction

There is a strong impetus for the use of telemedicine for boosting early detection rates and enabling early treatment and remote monitoring of COVID-19 cases, particularly in chronically ill patients such as kidney transplant recipients (KTRs). However, data regarding the effectiveness of this practice are lacking.

Methods

In this retrospective, observational study with prospective data gathering we analyzed the outcomes of all confirmed COVID-19 cases (n = 955) in KTRs followed at our center between March 1, 2020, and April 30, 2022. Risk factors of COVID-19 related mortality were analyzed with focus on the role of early referral to the transplant center, which enabled early initiation of treatment and remote outpatient management. This proactive approach was dependent on the establishment and use of a telemedicine system, which facilitated patient-physician communication and expedited diagnostics and treatment. The main exposure evaluated was early referral of KTRs to the transplantation center after confirmed or suspected COVID-19 infection. The primary outcome was the association of early referral to the transplantation center with the risk of death within 30 days following a COVID-19 diagnosis, evaluated by logistic regression.

Results

We found that KTRs who referred their illness to the transplant center late had a higher 30-day mortality (4.5 vs. 13.6%, p < 0.001). Thirty days mortality after the diagnosis of COVID-19 was independently associated with late referral to the transplant center (OR 2.08, 95% CI 1.08-3.98, p = 0.027), higher age (OR 1.09, 95% CI 1.05-1.13, p < 0.001), higher body mass index (OR 1.06, 95% CI 1.01-1.12, p = 0.03), and lower eGFR (OR 0.96, 95% CI 0.94-0.98, p < 0.001) in multivariable logistic regression. Furthermore, KTRs who contacted the transplant center late were older, had longer time from transplantation, lived farther from the center and presented with higher Charlson comorbidity index.

Discussion

A well-organized telemedicine program can help to protect KTRs during an infectious disease outbreak by facilitating pro-active management and close surveillance. Furthermore, these results can be likely extrapolated to other vulnerable populations, such as patients with chronic kidney disease, diabetes or autoimmune diseases requiring the use of immunosuppression.

True prevalence of long COVID in children: a narrative review

Contrary to what is true for adults, little is known about pediatric long COVID (LC). Studies enrolling children are relatively few and extremely heterogeneous. This does not allow to draw definitive conclusions on the frequency and pathogenesis of pediatric LC and limits the development of appropriate and effective measures to contain the clinical, social and economic impact of this condition on the pediatric population. Depending on the methods used to collect and analyze data, studies have found that the incidence rate of pediatric LC may vary from about 25% to less than 5%. However, despite true prevalence of pediatric LC cannot be exactly defined, studies comparing children with previous COVID-19 and uninfected controls have shown that most of the clinical manifestations detected in infected children, mainly mood symptoms, mental health disorders and heart abnormalities could be diagnosed with similar frequency and severity in uninfected subjects also. This seems to indicate that SARS-CoV-2 is the cause of pediatric LC only in a part of children and other factors play a relevant role in this regard. Pandemic itself with the persistent disruption of child lives may have caused persistent stress in all the pediatric population causing mood symptoms, mental health disorders or several organ and body system functional alterations, regardless SARS-CoV-2 infection. These suppositions suggest the need for long-term physical control of all the children after COVID-19 especially when they were already suffering from an underlying disease or have had a severe disease. Moreover, attention should be paid to the assessment of change in children's emotional and behavioral functioning in order to assure adequate interventions for the best emotional and behavioral well being. However, whatever its origin, it seems highly likely that the prevalence of the pediatric LC is set to decline in the future. Preliminary observations seem to suggest that recently developed SARS-CoV-2 variants are associated with less severe COVID-19. This suggests that, as already seen in adults, a lower number of pediatric virus-associated LC cases should occur. Furthermore, the use of COVID-19 vaccines, reducing incidence and severity of SARS-CoV-2 infection, may reduce risk of LC development. Finally, elimination of restrictive measures should significantly reduce mood symptoms and mental health disorders.

Remote psychophysical testing of smell in patients with persistent olfactory dysfunction after COVID-19

Olfactory dysfunction associated with coronavirus 2 (SARS-CoV-2) infection is in most cases transient, recovering spontaneously within a few days. However, in some patients it persists for a long time, affects their everyday life and endangers their health. Hence, we focused on patients with persistent loss of smell. The aim of this study was to evaluate olfactory dysfunction using a standardized test. Due to the pandemic, olfactory testing was performed online. Smell tests (Odorized Markers Test, OMT) were sent home to the patients. Together with the smell self-testing, participants reported and assessed several parameters (age, sex, subjective assessment of smell and taste, nasal patency, etc.) in an online questionnaire. Based on the questionnaire outcomes, the results were sent to the patients along with a list of participating otolaryngologists who provided them with professional care. From March to June 2021, 1025 patients requested smell testing, of these, 824 met the inclusion criteria of this study. The duration of the olfactory dysfunction at the time of testing ranged from 1 month to 1 year. Using the OMT, impaired smell ability-anosmia or hyposmia-was confirmed in 82.6% of participants. A total of 17.4% of participants were determined to be normosmic however, more than 50% of them complained of parosmia and/or phantosmia. Our study demonstrates the relevance of psychophysical smell testing and its suitability for remote use during the pandemic. This study also revealed several correlations between prolonged olfactory dysfunction and the monitored parameters.

Symptom profiles of community cases infected by influenza, RSV, rhinovirus, seasonal coronavirus, and SARS-CoV-2 variants of concern

Respiratory viruses that were suppressed through previous lockdowns during the COVID-19 pandemic have recently started to co-circulate with SARS-CoV-2. Understanding the clinical characteristics and symptomatology of different respiratory viral infections can help address the challenges related to the identification of cases and the understanding of SARS-CoV-2 variants' evolutionary patterns. Flu Watch (2006-2011) and Virus Watch (2020-2022) are household community cohort studies monitoring the epidemiology of influenza, respiratory syncytial virus, rhinovirus, seasonal coronavirus, and SARS-CoV-2, in England and Wales. This study describes and compares the proportion of symptoms reported during illnesses infected by common respiratory viruses. The SARS-CoV-2 symptom profile increasingly resembles that of other respiratory viruses as new strains emerge. Increased cough, sore throat, runny nose, and sneezing are associated with the emergence of the Omicron strains. As SARS-CoV-2 becomes endemic, monitoring the evolution of its symptomatology associated with new variants will be critical for clinical surveillance.

Impact of the first wave of COVID-19 on Crohn's disease after the end of "zero-COVID" policy in China

Background

The incidence and severity of coronavirus disease 2019 (COVID-19) among Crohn's disease (CD) patients are unknown in China. This study aimed to clarify the clinical courses and outcomes of CD patients in the first COVID-19 wave after the end of "zero-COVID" policy in China.

Methods

Clinical characteristics, including vaccination doses and medications of 880 CD patients from a prospective cohort were collected for analysis.

Results

Of the enrolled patients (n = 880) who underwent nucleic acid or antigen testing for COVID-19 from Dec 7, 2022, to Jan 7, 2023, 779 (88.5%) were infected with COVID-19. Among the infected patients, 755 (96.9%) were mild, 14 (1.8%) were moderate, one patient with leukemia died of cerebral hemorrhage (mortality, 0.1%) and only 9 (1.2%) were asymptomatic. Fever, cough, headache and appetite loss were the most frequently observed symptoms in general, respiratory, neurological and gastrointestinal manifestations, respectively. The age and disease duration were significantly higher (40/32, 5.6/3.6, all p < 0.05) in moderate patients than those in mild patients. All other clinical characteristics, including CD activity and medication exposure, showed no significant differences between the above two groups. Furthermore, no significant difference in vaccination or comorbidities was observed between the two groups.

Conclusion

Most CD patients contracted the Omicron infection and experienced mild disease courses in the first COVID-19 wave attack after China ended the "zero-COVID" policy irrespective of vaccination dose or comorbidities.

Short-term exposure to ambient air pollution and COVID-19 severity during SARS-CoV-2 Delta and Omicron waves: A multicenter study

Air pollution may affect the clinical course of respiratory diseases, including COVID-19. This study aimed to evaluate the relationship between exposure of adult patients to mean 24 h levels of particulate matter sized <10 μm (PM₁₀ ) and <2.5 μm (PM_2.5 ) and benzo(a)pyrene (B(a)P) during a week before their hospitalization due to SARS-CoV-2 infection and symptomatology, hyperinflammation, coagulopathy, the clinical course of disease, and outcome. The analyses were conducted during two pandemic waves: (i) dominated by highly pathogenic Delta variant (n = 1440) and (ii) clinically less-severe Omicron (n = 785), while the analyzed associations were adjusted for patient's age, BMI, gender, and comorbidities. The exposure to mean 24 h B(a)P exceeding the limits was associated with increased odds of fever and fatigue as early COVID-19 symptoms, hyperinflammation due to serum C-reactive protein >200 mg/L and interleukin-6 >100 pg/mL, coagulopathy due to  d-dimer >2 mg/L and fatal outcome. Elevated PM₁₀ and PM_{2. 5} levels were associated with higher odds of respiratory symptoms, procalcitonin >0.25 ng/mL and interleukin >100 pg/mL, lower oxygen saturation, need for oxygen support, and death. The significant relationships between exposure to air pollutants and the course and outcomes of COVID-19 were observed during both pandemic waves. Short-term exposure to elevated PM and B(a)P levels can be associated with a worse clinical course of COVID-19 in patients requiring hospitalization and, ultimately, contribute to the health burden caused by SARS-CoV-2 variants of higher and lower clinical significance.

Tracking the first SARS-CoV-2 Omicron BA.5.1.3 outbreak in China

The SARS-CoV-2 is still undergoing rapid evolution, resulting in the emergence of several variants of concern, especially the Omicron variants (B.1.1.529), which are surging worldwide. In this study, we tracked Omicron subvariant BA.5.1.3 as the causative agent in the Hainan Province wave in China, which started on 1 August 2022. This was China's first case of Omicron subvariant BA.5.1.3 and led to an indefinite total lockdown in Hainan with more than 8,500 confirmed cases. We obtained 391 whole genomes from positive nasopharyngeal swab samples in the city of Sanya in Hainan Province, which was the center of this outbreak. More than half of the infected cases were female (58%, 227/391) with a median age of 37.0 years (IQR 23.0-53.0). Median Ct values were 24.9 (IQR 22.6-27.3) and 25.2 (IQR 22.9-27.6) for ORF1ab and N genes, respectively. The total single-nucleotide polymorphism (SNP) numbers of Omicron BA.5.1.3 sampled in Sanya (median 69.0, IQR = 69.0-70.0) compared to those worldwide (median 63.0, IQR = 61.0-64.0) showed a significant difference (p < 0.05). Unique core mutations, including three non-synonymous mutations in ORF1ab (Y1064N, S2844G, and R3574K) and one synonymous mutation in ORF3a (S74S), were found. Phylogenetic analysis showed that virus from Sanya formed an independent sub-clade within the BA.5.1.3 subvariant, and could be divided into 15 haplotypes based on the S gene. The most recent common ancestor for the virus from Sanya was estimated as appearing on 5 July 2022, with 95% HPD ranging from 15 May to 20 September 2022. Thanks to our results, we were also able to delineate the mutational profile of this outbreak and highlight the importance of global genomic surveillance and data sharing.

COVID-19, post-acute COVID-19 syndrome (PACS, "long COVID") and post-COVID-19 vaccination syndrome (PCVS, "post-COVIDvac-syndrome"): Similarities and differences

Worldwide there have been over 760 million confirmed coronavirus disease 2019 (COVID-19) cases, and over 13 billion COVID-19 vaccine doses have been administered as of April 2023, according to the World Health Organization. An infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to an acute disease, i.e. COVID-19, but also to a post-acute COVID-19 syndrome (PACS, "long COVID"). Currently, the side effects of COVID-19 vaccines are increasingly being noted and studied. Here, we summarise the currently available indications and discuss our conclusions that (i) these side effects have specific similarities and differences to acute COVID-19 and PACS, that (ii) a new term should be used to refer to these side effects (post-COVID-19 vaccination syndrome, PCVS, colloquially "post-COVIDvac-syndrome"), and that (iii) there is a need to distinguish between acute COVID-19 vaccination syndrome (ACVS) and post-acute COVID-19 vaccination syndrome (PACVS) - in analogy to acute COVID-19 and PACS ("long COVID"). Moreover, we address mixed forms of disease caused by natural SARS-CoV-2 infection and COVID-19 vaccination. We explain why it is important for medical diagnosis, care and research to use the new terms (PCVS, ACVS and PACVS) in order to avoid confusion and misinterpretation of the underlying causes of disease and to enable optimal medical therapy. We do not recommend to use the term "Post-Vac-Syndrome" as it is imprecise. The article also serves to address the current problem of "medical gaslighting" in relation to PACS and PCVS by raising awareness among the medical professionals and supplying appropriate terminology for disease.

Plasma metabolomic characterization of SARS-CoV-2 Omicron infection

Omicron variants of SARS-CoV-2 have spread rapidly worldwide; however, most infected patients have mild or no symptoms. This study aimed to understand the host response to Omicron infections by performing metabolomic profiling of plasma. We observed that Omicron infections triggered an inflammatory response and innate immune, and adaptive immunity was suppressed, including reduced T-cell response and immunoglobulin antibody production. Similar to the original SARS-CoV-2 strain circulating in 2019, the host developed an anti-inflammatory response and accelerated energy metabolism in response to Omicron infection. However, differential regulation of macrophage polarization and reduced neutrophil function has been observed in Omicron infections. Interferon-induced antiviral immunity was not as strong in Omicron infections as in the original SARS-CoV-2 infections. The host response to Omicron infections increased antioxidant capacity and liver detoxification more than in the original strain. Hence, these findings suggest that Omicron infections cause weaker inflammatory alterations and immune responses than the original SARS-CoV-2 strain.

SARS-CoV-2 before and after Omicron: two different viruses and two different diseases?

For the first time in the history of medicine, it has been possible to describe-after a spillover-the evolution of a new human virus spreading in a non-immune population. This allowed not only to observe the subsequent emersion of variants endowed with features providing the virus with an evolutionary advantage, but also the shift of the pathways of virus replication and the acquisition of immunoevasive features. These characteristics had a remarkable influence on the diffusion of the SARS-CoV-2 and on the clinical presentation and prognosis of COVID-19, aspects that are described and commented in this review.

Variant-Related Differences in Laboratory Biomarkers among Patients Affected with Alpha, Delta and Omicron: A Retrospective Whole Viral Genome Sequencing and Hospital-Setting Cohort Study

During the COVID-19 pandemic, different SARS-CoV-2 variants of concern (VOC) with specific characteristics have emerged and spread worldwide. At the same time, clinicians routinely evaluate the results of certain blood tests upon patient admission as well as during hospitalization to assess disease severity and the overall patient status. In the present study, we searched for significant cell blood count and biomarker differences among patients affected with the Alpha, Delta and Omicron VOCs at admission. Data from 330 patients were retrieved regarding age, gender, VOC, cell blood count results (WBC, Neut%, Lymph%, Ig%, PLT), common biomarkers (D-dimers, urea, creatinine, SGOT, SGPT, CRP, IL-6, suPAR), ICU admission and death. Statistical analyses were performed using ANOVA, the Kruskal-Wallis test, two-way ANOVA, Chi-square, T-test, the Mann-Whitney test and logistic regression was performed where appropriate using SPSS v.28 and STATA 14. Age and VOC were significantly associated with hospitalization, whereas significant differences among VOC groups were found for WBC, PLT, Neut%, IL-6, creatinine, CRP, D-dimers and suPAR. Our analyses showed that throughout the current pandemic, not only the SARS-CoV-2 VOCs but also the laboratory parameters that are used to evaluate the patient's status at admission are subject to changes.

COVID-19 Patterns in Araraquara, Brazil: A Multimodal Analysis

The epidemiology of COVID-19 presented major shifts during the pandemic period. Factors such as the most common symptoms and severity of infection, the circulation of different variants, the preparedness of health services, and control efforts based on pharmaceutical and non-pharmaceutical interventions played important roles in the disease incidence. The constant evolution and changes require the continuous mapping and assessing of epidemiological features based on time-series forecasting. Nonetheless, it is necessary to identify the events, patterns, and actions that were potential factors that affected daily COVID-19 cases. In this work, we analyzed several databases, including information on social mobility, epidemiological reports, and mass population testing, to identify patterns of reported cases and events that may indicate changes in COVID-19 behavior in the city of Araraquara, Brazil. In our analysis, we used a mathematical approach with the fast Fourier transform (FFT) to map possible events and machine learning model approaches such as Seasonal Auto-regressive Integrated Moving Average (ARIMA) and neural networks (NNs) for data interpretation and temporal prospecting. Our results showed a root-mean-square error (RMSE) of about 5 (more precisely, a 4.55 error over 71 cases for 20 March 2021 and a 5.57 error over 106 cases for 3 June 2021). These results demonstrated that FFT is a useful tool for supporting the development of the best prevention and control measures for COVID-19.

Predictors for reactogenicity and humoral immunity to SARS-CoV-2 following infection and mRNA vaccination: A regularized, mixed-effects modelling approach

Introduction

The influence of pre-existing humoral immunity, inter-individual demographic factors, and vaccine-associated reactogenicity on immunogenicity following COVID vaccination remains poorly understood.

Methods

Ten-fold cross-validated least absolute shrinkage and selection operator (LASSO) and linear mixed effects models were used to evaluate symptoms experienced by COVID+ participants during natural infection and following SARS-CoV-2 mRNA vaccination along with demographics as predictors for antibody (AB) responses to recombinant spike protein in a longitudinal cohort study.

Results

In previously infected individuals (n=33), AB were more durable and robust following primary vaccination when compared to natural infection alone. Higher AB were associated with experiencing dyspnea during natural infection, as was the total number of symptoms reported during the COVID-19 disease course. Both local and systemic symptoms following 1st and 2nd dose (n=49 and 48, respectively) of SARS-CoV-2 mRNA vaccines were predictive of higher AB after vaccination. Lastly, there was a significant temporal relationship between AB and days since infection or vaccination, suggesting that vaccination in COVID+ individuals is associated with a more robust immune response.

Discussion

Experiencing systemic and local symptoms post-vaccine was suggestive of higher AB, which may confer greater protection.

Development and validation of a nomogram to predict failure of 14-day negative nucleic acid conversion in adults with non-severe COVID-19 during the Omicron surge: a retrospective multicenter study

BACKGROUND

With the variability in emerging data, guidance on the isolation duration for patients with coronavirus disease 2019 (COVID-19) due to the Omicron variant is controversial. This study aimed to determine the predictors of prolonged viral RNA shedding in patients with non-severe COVID-19 and construct a nomogram to predict patients at risk of 14-day PCR conversion failure.

METHODS

Adult patients with non-severe COVID-19 were enrolled from three hospitals of eastern China in Spring 2022. Viral shedding time (VST) was defined as either the day of the first positive test or the day of symptom onset, whichever was earlier, to the date of the first of two consecutively negative PCR tests. Patients from one hospital (Cohort I, n = 2033) were randomly grouped into training and internal validation sets. Predictors of 14-day PCR conversion failure were identified and a nomogram was developed by multivariable logistic regression using the training dataset. Two hospitals (Cohort II, n = 1596) were used as an external validation set to measure the performance of this nomogram.

RESULTS

Of the 2033 patients from Cohort I, the median VST was 13.0 (interquartile range: 10.0‒16.0) days; 716 (35.2%) lasted > 14 days. In the training set, increased age [per 10 years, odds ratio (OR) = 1.29, 95% confidence interval (CI): 1.15‒1.45, P < 0.001] and high Charlson comorbidity index (OR = 1.25, 95% CI: 1.08‒1.46, P = 0.004) were independent risk factors for VST > 14 days, whereas full or boosted vaccination (OR = 0.63, 95% CI: 0.42‒0.95, P = 0.028) and antiviral therapy (OR = 0.56, 95% CI: 0.31‒0.96, P = 0.040) were protective factors. These predictors were used to develop a nomogram to predict VST > 14 days, with an area under the ROC curve (AUC) of 0.73 in the training set (AUC, 0.74 in internal validation set; 0.76 in external validation set).

CONCLUSIONS

Older age, increasing comorbidities, incomplete vaccinations, and lack of antiviral therapy are risk factors for persistent infection with Omicron variant for > 14 days. A nomogram based on these predictors could be used as a prediction tool to guide treatment and isolation strategies.

A multidimensional approach to older patients during COVID-19 pandemic: a position paper of the Special Interest Group on Comprehensive Geriatric Assessment of the European Geriatric Medicine Society (EuGMS)

PURPOSE

The COVID-19 pandemic has been a dramatic trigger that has challenged the intrinsic capacity of older adults and of society. Due to the consequences for the older population worldwide, the Special Interest Group on Comprehensive Geriatric Assessment (CGA) of the European Geriatric Medicine Society (EuGMS) took the initiative of collecting evidence on the usefulness of the CGA-based multidimensional approach to older people during the COVID-19 pandemic.

METHODS

A narrative review of the most relevant articles published between January 2020 and November 2022 that focused on the multidimensional assessment of older adults during the COVID-19 pandemic.

RESULTS

Current evidence supports the critical role of the multidimensional approach to identify older adults hospitalized with COVID-19 at higher risk of longer hospitalization, functional decline, and short-term mortality. This approach appears to also be pivotal for the adequate stratification and management of the post-COVID condition as well as for the adoption of preventive measures (e.g., vaccinations, healthy lifestyle) among non-infected individuals.

CONCLUSION

Collecting information on multiple health domains (e.g., functional, cognitive, nutritional, social status, mobility, comorbidities, and polypharmacy) provides a better understanding of the intrinsic capacities and resilience of older adults affected by SARS-CoV-2 infection. The EuGMS SIG on CGA endorses the adoption of the multidimensional approach to guide the clinical management of older adults during the COVID-19 pandemic.

Safety and Efficacy of Paxlovid Against Omicron Variants of Coronavirus Disease 2019 in Elderly Patients

INTRODUCTION

Elderly patients are the most affected and vulnerable to COVID-19 and effective therapeutic interventions are urgently required. We clarified the safety and efficacy of Paxlovid in the treatment of elderly patients with coronavirus disease 2019 (COVID-19).

METHODS

Patients aged over 60 years and with mild to moderate COVID-19 were admitted to the Zhongshan Hospital MinHang MeiLong Branch, Fudan University and received either Paxlovid treatment or only conventional therapy, between April 1 and May 31, 2022. Viral shedding time, duration of hospital stay, disease progression, and adverse events were analyzed, and multivariate Cox regression analysis was performed to detect the independent high-risk factors for COVID-19 progression in the patients.

RESULTS

A total of 163 (82 and 81 in the treatment and control groups, respectively) patients had a median age of 82 (71-89) years, and 89.0% had at least one concomitant disease. The duration of hospitalization reduced from 15 to 13 days, and viral shedding time reduced from 20 to 16.5 days after Paxlovid treatment. The differences of these two variables between the groups were significant (p < 0.01). Moreover, no serious adverse events or obvious changes in laboratory test results were observed in patients treated with Paxlovid. One patient (1.2%) treated with Paxlovid experienced rebound 56 days after negative measurement. Multivariate analysis showed that Paxlovid therapy, age, hemoglobin, and nucleic acid Ct values at admission were independent risk factors for hospitalization within 14 days, and the differences were significant (p < 0.01).

CONCLUSION

The use of Paxlovid in elderly patients may promote recovery from COVID-19 and reduce the viral load without adverse events.

CLINICAL TRIAL REGISTRATION

www.

CLINICALTRIALS

gov , ID: ChiCTR2200066990.

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.

Ocular Symptoms Associated with COVID-19 Are Correlated with the Expression Profile of Mouse SARS-CoV-2 Binding Sites

The COVID-19 pandemic has engendered significant scientific efforts in the understanding of its infectious agent SARS-CoV-2 and of its associated symptoms. A peculiar characteristic of this virus lies in its ability to challenge our senses, as its infection can lead to anosmia and ageusia. While ocular symptoms, such as conjunctivitis, optic neuritis or dry eyes, are also reported after viral infection, they have lower frequencies and severities, and their functional development is still elusive. Here, using combined technical approaches based on histological and gene profiling methods, we characterized the expression of SARS-CoV-2 binding sites (Ace2/Tmprss2) in the mouse eye. We found that ACE2 was ectopically expressed in subtissular ocular regions, such as in the optic nerve and in the Harderian/intraorbital lacrimal glands. Moreover, we observed an important variation of Ace2/Tmprss2 expression that is not only dependent on the age and sex of the animal, but also highly heterogenous between individuals. Our results thus give new insight into the expression of SARS-CoV-2 binding sites in the mouse eye and propose an interpretation of the human ocular-associated symptoms linked to SARS-CoV-2.

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.