Prevalence and Duration of Acute Loss of Smell or Taste in COVID-19 Patients

Frequency of SARS-CoV-2 Infections among Healthcare Workers in Germany: 3-Year Follow-Up Study

The emergence of SARS-CoV-2 in 2019 led to a global pandemic with a significant impact on healthcare systems. Healthcare workers were particularly vulnerable due to frequent contact with COVID-19 patients. Despite vaccination, they remained at higher risk as the vaccines provided limited protection against infection with viral variants, like Delta or Omicron BA.1 and BA.5. Three years after the onset of the pandemic, we evaluated SARS-CoV-2 infection frequencies among healthcare workers with varying levels of patient contact: high-risk (frequent COVID-19 patient contact), intermediate-risk (non-COVID-19 patient contact), and low-risk (no patient contact). We assessed their cellular and humoral immune responses based on their vaccination status and number of prior infections. SARS-CoV-2-specific antibodies were measured by immunoglobulin ELISA, and neutralizing antibody titers were determined against the viral variants D614G, Delta, and Omicron BA.1 and BA.5. Cellular immune responses were analyzed using an interferon-γ ELISpot. Notably, three years into the pandemic, healthcare workers in daily contact with COVID-19 patients did not have higher infection rates compared to healthcare workers with non-COVID-19 patient contact or no patient contact. Immune responses were similar across all groups, highlighting the effectiveness of vaccination and current hygiene standards in preventing virus transmission from patients to staff.

The long-term effect of COVID-19 infection on olfaction and taste; a prospective analysis

PURPOSE

To estimate long-term prognosis of chemosensory dysfunctions among patients recovering from COVID-19 disease.

METHODS

Between April 2020 and July 2022, we conducted a prospective, observational study enrolling 48 patients who experienced smell and/or taste dysfunction during the acute-phase of COVID-19. Patients were evaluated for chemosensory function up to 24 months after disease onset.

RESULTS

During the acute-phase of COVID-19, 80% of patients reported anosmia, 15% hyposmia, 63% ageusia, and 33% hypogeusia. At two years' follow-up, 53% still experienced smell impairment, and 42% suffered from taste impairment. Moreover, 63% of patients who reported parosmia remained with olfactory disturbance. Interestingly, we found a negative correlation between visual analogue scale scores for smell and taste impairments during the acute-phase of COVID-19 and the likelihood of long-term recovery.

CONCLUSION

Our study sheds light on the natural history and long-term follow-up of chemosensory dysfunction in patients recovering from COVID-19 disease. Most patients who initially suffered from smell and/or taste disturbance did not reach full recovery after 2 years follow-up. The severity of impairment may serve as a prognostic indicator for full recovery.

Histopathology of the Tongue in a Hamster Model of COVID-19

Objective

With altered sense of taste being a common symptom of coronavirus disease 2019 (COVID-19), our objective was to investigate the presence and distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) within the tongue over the course of infection.

Methods

Golden Syrian hamsters were inoculated intranasally with SARS-CoV-2 and tongues were collected at 2, 3, 5, 8, 17, 21, 35, and 42 days post-infection (dpi) for analysis. In order to test for gross changes in the tongue, the papillae of the tongue were counted. Paraffin-embedded thin sections of the tongues were labeled for the presence of SARS-CoV-2 antigen.

Results

There was no difference in fungiform or filiform papillae density throughout the course of infection. SARS-CoV-2 antigen was observed in the circumvallate papillae taste buds (3-35 dpi) and autonomic ganglia (5-35 dpi), as well as in the serous and mucous salivary glands of the posterior tongue (2-42 dpi).

Conclusion

The presence and distribution of SARS-CoV-2 suggest that the virus could cause taste disturbance by infecting the circumvallate taste buds. This effect could be exacerbated by a diminished secretion of saliva caused by infection of the serous salivary glands and the autonomic ganglia which innervate them.

COVID-19-related chemosensory changes: Findings from a prospective national database

Objective

The aim of this study was to review findings from a large prospective national database of chemosensory disturbances associated with coronavirus disease 2019 (COVID-19) infection.

Data Sources

The Virginia Commonwealth University Smell and Taste Center national database of COVID-19 chemosensory disturbances.

Methods

A series of online surveys, first opened on April 10, 2020, was made accessible nationwide to any adult with sudden chemosensory dysfunction since January 2020. Participants received subsequent follow-up surveys 14 days, 1 month, 3 months, and 6 months after enrollment. An additional survey was sent to all participants on May 28, 2022 to assess long-term outcomes. Information pertaining to demographics, symptoms, comorbidities, treatments, and life impact was collected.

Results

Of 363 participants who reported complete smell recovery, 51.2% recovered within 1 month, 70% within 3 months, and 79% within 6 months, while 8.8% took over 1 year to completely recover. Among all participants, 7.5% had no smell recovery. Positive predictors of recovery included age <40, male gender, and the presence of nasal congestion. Negative predictors included difficulty breathing and prior head injury. Many participants reported a decrease in quality of life and the presence of potential safety hazards associated with decreased smell loss.

Conclusions

Most subjects with COVID-19-related chemosensory dysfunction recover, with the majority noting complete recovery within weeks of infection. Those aged over 40 years and female gender were associated with lower rates of recovery. A considerable number of participants reported significant impact on quality of life and safety.

Olfactory immunology: the missing piece in airway and CNS defence

The olfactory mucosa is a component of the nasal airway that mediates the sense of smell. Recent studies point to an important role for the olfactory mucosa as a barrier to both respiratory pathogens and to neuroinvasive pathogens that hijack the olfactory nerve and invade the CNS. In particular, the COVID-19 pandemic has demonstrated that the olfactory mucosa is an integral part of a heterogeneous nasal mucosal barrier critical to upper airway immunity. However, our insufficient knowledge of olfactory mucosal immunity hinders attempts to protect this tissue from infection and other diseases. This Review summarizes the state of olfactory immunology by highlighting the unique immunologically relevant anatomy of the olfactory mucosa, describing what is known of olfactory immune cells, and considering the impact of common infectious diseases and inflammatory disorders at this site. We will offer our perspective on the future of the field and the many unresolved questions pertaining to olfactory immunity.

COVID-19: Unveiling the Neuropsychiatric Maze-From Acute to Long-Term Manifestations

The SARS-CoV-2 virus has spread rapidly despite implementing strategies to reduce its transmission. The disease caused by this virus has been associated with a diverse range of symptoms, including common neurological manifestations such as dysgeusia, anosmia, and myalgias. Additionally, numerous cases of severe neurological complications associated with this disease have been reported, including encephalitis, stroke, seizures, and Guillain-Barré syndrome, among others. Given the high prevalence of neurological manifestations in this disease, the objective of this review is to analyze the mechanisms by which this virus can affect the nervous system, from its direct invasion to aberrant activation of the immune system and other mechanisms involved in the symptoms, including neuropsychiatric manifestations, to gain a better understanding of the disease and thus facilitate the search for effective therapeutic strategies.

Long-COVID impacts taste and olfactory in individuals with substance use disorder: A retrospective cohort study from the TriNetX US Collaborative Networks

Substance use disorder (SUD) exacerbates the impact of Long-COVID, particularly increasing the risk of taste and olfactory disorders. Analyzing retrospective cohort data from TriNetX and over 33 million records (Jan 2020-Dec 2022), this study focused on 1,512,358 participants, revealing that SUD significantly heightens the likelihood of experiencing taste disturbances and anosmia in Long-COVID sufferers. Results indicated that individuals with SUD face a higher incidence of sensory impairments compared to controls, with older adults and women being particularly vulnerable. Smokers with SUD were found to have an increased risk of olfactory and taste dysfunctions. The findings underscore the importance of early screening, diagnosis, and interventions for Long-COVID patients with a history of SUD, suggesting a need for clinicians to monitor for depression and anxiety linked to sensory dysfunction for comprehensive care.

Long-Term effects of COVID-19: a review of current perspectives and mechanistic insights

Although SARS-CoV-2, responsible for COVID-19, is primarily a respiratory infection, a broad spectrum of cardiac, pulmonary, neurologic, and metabolic complications can occur. More than 50 long-term symptoms of COVID-19 have been described, and as many as 80% of patients may develop ≥1 long-term symptom. To summarize current perspectives of long-term sequelae of COVID-19, we conducted a PubMed search describing the long-term cardiovascular, pulmonary, gastrointestinal, and neurologic effects post-SARS-CoV-2 infection and mechanistic insights and risk factors for the above-mentioned sequelae. Emerging risk factors of long-term sequelae include older age (≥65 years), female sex, Black or Asian race, Hispanic ethnicity, and presence of comorbidities. There is an urgent need to better understand ongoing effects of COVID-19. Prospective studies evaluating long-term effects of COVID-19 in all body systems and patient groups will facilitate appropriate management and assess burden of care. Clinicians should ensure patients are followed up and managed appropriately, especially those in at-risk groups. Healthcare systems worldwide need to develop approaches to follow-up and support patients recovering from COVID-19. Surveillance programs can enhance prevention and treatment efforts for those most vulnerable.

Assessment of olfactory recovery after COVID-19: cross-sectional study

OBJECTIVE

This study aimed to evaluate recovery patterns of olfactory dysfunction among recovered COVID-19 patients, both subjective and objective, and correlate this recovery to the severity of the disease.

METHODS

The study recruited 200 patients and assigned them to two equal groups, one of them was a control group. The olfactory function of the study group was assessed via subjective and objective methods at baseline and then monthly for three months, with changes in smell function reported at each visit. These patients underwent chemosensory testing using the Sniffin' Sticks test and completed the validated Arabic version of the Questionnaire of Olfactory Disorders-Negative Statements (QOD-NS).

RESULTS

Olfactory dysfunction occurred on the first day of COVID-19 symptoms in 37% of participants. Subjective reports suggested smell recovery in 55% after 3 months, but Sniffin' Sticks showed only 1% with normal function, indicating persistent deficits in others. This study revealed smell recovery for 93% of participants (median 14 days), with most (58%) recovering within 2 weeks. No significant links were found between demographics, COVID-smell loss timing, and recovery speed.

CONCLUSION

Three months after COVID-19, many patients perceive smell recovery, but objective tests reveal shockingly high rates of persistent dysfunction. Further follow-up with objective tests is vital to assess the true burden and potential long-term effects of smell loss.

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.

Long-term smell loss experiences after COVID-19: A qualitative study

OBJECTIVES

Sudden smell loss is one of the early symptoms of COVID-19. Although it is stated that the loss of smell and taste following COVID-19 improves within a few weeks, there are also cases that do not improve for a long time. The aim of this study is to reveal long-term smell loss experiences after COVID-19.

METHODS

A qualitative approach was adopted. We conducted semistructured interviews with 11 participants who had smell loss for at least 3 months. Interviews were recorded, transcribed and evaluated using a thematic analysis for qualitative data.

RESULTS

Nutrition and appetite, personal hygiene, threats to safety and emotional changes were the main themes created by the authors and were the areas where participant expressions focused. The participants used oral/nasal corticosteroid therapy for smell loss and received short-term olfactory training, but could not find a solution.

CONCLUSIONS

Long-term smell loss problems, which were neglected during the pandemic period, should be carefully evaluated due to their negative effects. Understanding and focusing on the negative effects of loss of smell may contribute to the solution of long-term smell loss problems.

PATIENT AND PUBLIC CONTRIBUTION

Eleven participants who experienced long-term loss of smell following COVID-19 contributed to the study. They enriched the study by describing the effects of their experiences. There was no other participation or contribution from the public to the research.

Pathophysiological, immunological, and inflammatory features of long COVID

The COVID-19 pandemic continues to cause severe global disruption, resulting in significant excess mortality, overwhelming healthcare systems, and imposing substantial social and economic burdens on nations. While most of the attention and therapeutic efforts have concentrated on the acute phase of the disease, a notable proportion of survivors experience persistent symptoms post-infection clearance. This diverse set of symptoms, loosely categorized as long COVID, presents a potential additional public health crisis. It is estimated that 1 in 5 COVID-19 survivors exhibit clinical manifestations consistent with long COVID. Despite this prevalence, the mechanisms and pathophysiology of long COVID remain poorly understood. Alarmingly, evidence suggests that a significant proportion of cases within this clinical condition develop debilitating or disabling symptoms. Hence, urgent priority should be given to further studies on this condition to equip global public health systems for its management. This review provides an overview of available information on this emerging clinical condition, focusing on the affected individuals' epidemiology, pathophysiological mechanisms, and immunological and inflammatory profiles.

Olfactory immune response to SARS-CoV-2

Numerous pathogens can infect the olfactory tract, yet the pandemic caused by SARS-CoV-2 has strongly emphasized the importance of the olfactory mucosa as an immune barrier. Situated in the nasal passages, the olfactory mucosa is directly exposed to the environment to sense airborne odorants; however, this also means it can serve as a direct route of entry from the outside world into the brain. As a result, olfactotropic infections can have serious consequences, including dysfunction of the olfactory system, CNS invasion, dissemination to the lower respiratory tract, and transmission between individuals. Recent research has shown that a distinctive immune response is needed to protect this neuronal and mucosal tissue. A better understanding of innate, adaptive, and structural immune barriers in the olfactory mucosa is needed to develop effective therapeutics and vaccines against olfactotropic microbes such as SARS-CoV-2. Here, we summarize the ramifications of SARS-CoV-2 infection of the olfactory mucosa, review the subsequent immune response, and discuss important areas of future research for olfactory immunity to infectious disease.

Prevalence and Factors Associated with Olfactory Dysfunction in Individuals with COVID-19 in Brazil: A Study of 20,669 Cases from 2020 to 2021

OBJECTIVE

The aim of the study is to determine the prevalence and factors associated with olfactory dysfunction in individuals with COVID-19 in the first 2 years of the pandemic in Brazil.

MATERIALS AND METHODS

This is a prevalent study involving the confirmed cases of COVID-19 recorded in the municipality between the years 2020 and 2021. Individuals symptomatic for COVID-19, with a positive laboratory result and aged 12 or older were included in this study. Measures of central tendency and dispersion were used in the description of continuous variables and frequency was used for categorical variables. The Shapiro-Wilk test was used to evaluate data distribution.

RESULTS

Data from 20,669 individuals were analyzed. The prevalence of olfactory disorders was 17.9% and increased from 11.5% to 21.9% between 2020 and 2021. A female gender predominance was observed among individuals who reported anosmia, with 61.1% (n = 564) in 2020 and 61.7% (n = 1,713) in 2021. On the other hand, the median age of individuals with olfactory disorders was lower than that of the group without disorders (35 [IQR 27-46] vs. 39 [IQR 29-50]; p < 0.001). Smell disturbances were present in 18.2% (n = 3,634) of patients who recovered and in 7.1% (n = 38) of those who died. Furthermore, in 2021, a prevalence rate of 30.6% for olfactory disorders was linked to obesity as a comorbidity.

CONCLUSION

The prevalence of olfactory disorders was lower compared to other studies, with cough and fever being negatively related to olfactory dysfunction and headache, coryza, and taste disorders being positively related. Obesity was the only associated comorbidity.

Human-derived air-liquid interface cultures decipher Alzheimer's disease-SARS-CoV-2 crosstalk in the olfactory mucosa

BACKGROUND

The neurological effects of the coronavirus disease of 2019 (COVID-19) raise concerns about potential long-term consequences, such as an increased risk of Alzheimer's disease (AD). Neuroinflammation and other AD-associated pathologies are also suggested to increase the risk of serious SARS-CoV-2 infection. Anosmia is a common neurological symptom reported in COVID-19 and in early AD. The olfactory mucosa (OM) is important for the perception of smell and a proposed site of viral entry to the brain. However, little is known about SARS-CoV-2 infection at the OM of individuals with AD.

METHODS

To address this gap, we established a 3D in vitro model of the OM from primary cells derived from cognitively healthy and AD individuals. We cultured the cells at the air-liquid interface (ALI) to study SARS-CoV-2 infection under controlled experimental conditions. Primary OM cells in ALI expressed angiotensin-converting enzyme 2 (ACE-2), neuropilin-1 (NRP-1), and several other known SARS-CoV-2 receptor and were highly vulnerable to infection. Infection was determined by secreted viral RNA content and confirmed with SARS-CoV-2 nucleocapsid protein (NP) in the infected cells by immunocytochemistry. Differential responses of healthy and AD individuals-derived OM cells to SARS-CoV-2 were determined by RNA sequencing.

RESULTS

Results indicate that cells derived from cognitively healthy donors and individuals with AD do not differ in susceptibility to infection with the wild-type SARS-CoV-2 virus. However, transcriptomic signatures in cells from individuals with AD are highly distinct. Specifically, the cells from AD patients that were infected with the virus showed increased levels of oxidative stress, desensitized inflammation and immune responses, and alterations to genes associated with olfaction. These results imply that individuals with AD may be at a greater risk of experiencing severe outcomes from the infection, potentially driven by pre-existing neuroinflammation.

CONCLUSIONS

The study sheds light on the interplay between AD pathology and SARS-CoV-2 infection. Altered transcriptomic signatures in AD cells may contribute to unique symptoms and a more severe disease course, with a notable involvement of neuroinflammation. Furthermore, the research emphasizes the need for targeted interventions to enhance outcomes for AD patients with viral infection. The study is crucial to better comprehend the relationship between AD, COVID-19, and anosmia. It highlights the importance of ongoing research to develop more effective treatments for those at high risk of severe SARS-CoV-2 infection.

Clinical factors influencing olfactory performance in patients with persistent COVID-19 smell loss longer than 1 year

Objectives

Factors affecting persistence of COVID-19-related olfactory dysfunction (OD) remain partially unknown. We aim to evaluate the clinical factors which could influence olfactory performance in patients with persistent COVID-19-related smell loss.

Methods

A retrospective analysis of 100 patients with persistent COVID-19-related OD was performed between October 2020 and December 2022 at a single-center long-COVID smell clinic. All subjects underwent smell assessment using Sniffin' Sticks (S'S) extended test, nasal endoscopy, nasal airflow evaluation (peak nasal inspiratory flow [PNIF]), allergy test (skin prick test [SPT]) for common aeroallergens, MRI of the head and patient-reported outcome measures (PROMs-VAS, SF-36, Short QOD-NS, SNOT-22). Based on S'S score, subjects were divided into normosmics (TDI ≥ 30.75) and dysosmics (TDI < 30.75).

Results

The median age was 42 years and the median length of patient-reported OD was 1.4 years. 20 patients (20.0%) were normosmic at the time of S'S assessment. Dysosmic patients were found to have significantly lower scores at the SF-36 health domains for energy/fatigue (p = .0004) and emotional wellbeing (p = .04) when compared to normosmics. A moderate correlation (r = .45-.59) between S'S scores and some PROMs was also demonstrated. At the multivariate analysis higher PNIF scores positively influenced odor threshold (p = .001) while positivity to SPT negatively influenced odor identification (p = .04).

Conclusions

Impairment of nasal airflow and sensitivity to aeroallergens can negatively affect olfactory performance in COVID-19-related OD. Long-COVID smell loss deeply affects QoL although recovery of olfaction can bring it back to a normal range.

Level of Evidence

IV.

Assessment of infection control in oral radiology during the COVID-19 outbreak: An international collaborative study

Purpose

In the context of COVID-19, studies evaluating the adherence of dentists and dental students to infection control are relevant due to their high occupational exposure and risk, as well as their responsibility for disseminating information and good practices. This study evaluated the adherence of dentists and dental students to infection control in the oral radiology field in the setting of the COVID-19 pandemic on different continents.

Materials and Methods

This cross-sectional observational study involved individuals who performed intraoral radiographic examinations during the COVID-19 pandemic. The Questionnaire on Infection Control in Oral Radiology was administered virtually using a Google Form. Participants from different continents (the Americas, Africa, Europe, Asia, and Oceania) were recruited. Data were subjected to descriptive analysis and simple and multiple binary regression (5%).

Results

There were 582 valid answers, and 68.73% of the participants were from the Americas, 18.90% from Europe, and 12.37% from Asia. The median score for infection control protocols was 94 points for dental students and 104 points for dentists, and participants below the median were considered to have low adherence to infection control in oral radiology. Low access to infection control was found for 53.0% of dentists in the Americas, 34.0% from Europe, and 26.9% from Asia.

Conclusion

The adherence to infection control protocols in oral radiology was low even in the face of the COVID-19 pandemic. The results may help improve the awareness of students and professionals, since oral radiology routines have the potential for transmitting COVID-19.

Recovery Patterns of COVID-19 Related Smell Disorders: An Analysis of the Available Evidence

Recently acquired olfactory dysfunction (OD) has emerged as one of hallmark manifestations of the novel Corona virus disease (COVID-19), but the evolution of its spontaneous recovery has remained inconclusive, with reports of persistence of OD beyond six months of onset. We undertook this systematic review and meta-analysis with a view to generating a pooled recovery rate of COVID-19 associated olfactory dysfunctions and attempt to examine the predictors of olfactory recovery. Systematic review and meta-analysis. A systematic search of Scopus, Google Scholar, and PubMed data bases, comprising all longitudinal studies reporting the trajectory of COVID-19 related OD was carried out. The pooled recovery rate was estimated with random-effects model, and the potential heterogeneity of the subgroup sources was analyzed using meta-regression test. After the PRISMA selection process 28 studies from 16 countries were included, with a total of 5,175 OD patients, among 11,948 COVID-19 cases. The estimated global pooled recovery rate of OD was 82.7% (95% CI, 77.46%-88.04%), with a pooled median duration of OD of 11.6 days. Only 2 out of 28 studies had recovery data beyond a period of 2 months. But no significant difference was found in the recovery rate regarding the length of follow up (P = 0.840). Studies that conducted objective olfactory assessments showed significant higher recovery rate than those with subjective assessments (P = 0.001). Although ten studies (36%) reported > 90% recovery, nine studies (32%) documented persistence of OD in > 25% of their patients. Five out of 6 studies showed that hyposmia tended to show complete recovery than anosmia. Age, co-morbidities, and intra-nasal treatments had no effects. Test of homogeneity between subgroups using the Cochran's Q test was not significant (Q = 0.69, P = 0.40). Our meta-analysis revealed high rate of early and medium term recovery of COVID-19 related OD. However, it also showed disturbing rates of persistence of OD. Anosmia tended to be predictive of residual OD than hyposmia. Age, co-morbidities, intra-nasal corticosteroid and decongestants, had no effects on OD recovery.

[Subjective and objectified smell and taste disorders from an ENT post-Covid-19 consultation]

INTRODUCTION

Olfactory disorders are among the four most common post-COVID-19 complaints. The aim of our prospective study from a university ENT post-COVID consultation (PCS) was to substantiate the symptoms with psychophysical test results.

METHODS

After an ENT examination, 60 post-COVID-19 patients (41 women) were asked in writing about their medical history. Their ability to smell was tested using the extended Sniffin' Sticks test battery and their ability to taste was determined using the 3-drop test. From these data, three quantitative olfactory (RD) and gustatory (SD) diagnoses could be defined from normal value tables. Every second patient took part in a control examination.

RESULTS

Up to the first examination, 60 patients reported smell and 51 taste disorders; their average duration was 11 months in both cases. Objectified pathologic RD and SD had 87% and 42% of the total cohort, respectively. Every third patient suffered from an objectified combination of olfactory and gustatory damage. About every second patient complained of parosmia. Parosmic patients with two visits came earlier for a check-up. Six months after the initial examination, the detection thresholds, the TDI and the RD had improved in these patients. The self-assessment of olfactory ability had not changed.

CONCLUSIONS

Objectified pathologic RD persisted in our PCS for a mean of 1.5 years from the onset of infection. Parosmics had a better prognosis. For the healthcare system and especially for the patients affected, they continue to be a burden even after the pandemic.

VEGFR and DPP-IV as Markers of Severe COVID-19 and Predictors of ICU Admission

The pathophysiology of the severe course of COVID-19 is multifactorial and not entirely elucidated. However, it is well known that the hyperinflammatory response and cytokine storm are paramount events leading to further complications. In this paper, we investigated the vascular response in the pathophysiology of severe COVID-19 and aimed to identify novel biomarkers predictive of ICU admission. The study group consisted of 210 patients diagnosed with COVID-19 (age range: 18-93; mean ± SD: 57.78 ± 14.16), while the control group consisted of 80 healthy individuals. We assessed the plasma concentrations of various vascular factors using the Luminex technique. Then, we isolated RNA from blood mononuclear cells and performed a bioinformatics analysis investigating various processes related to vascular response, inflammation and angiogenesis. Our results confirmed that severe COVID-19 is associated with vWF/ADAMTS 13 imbalance. High plasma concentrations of VEGFR and low DPP-IV may be potential predictors of ICU admission. SARS-CoV-2 infection impairs angiogenesis, hinders the generation of nitric oxide, and thus impedes vasodilation. The hypercoagulable state develops mainly in the early stages of the disease, which may contribute to the well-established complications of COVID-19.

Mechanism and treatment of olfactory dysfunction caused by coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the start of the pandemic, olfactory dysfunction (OD) has been reported as a common symptom of COVID-19. In some asymptomatic carriers, OD is often the first and even the only symptom. At the same time, persistent OD is also a long-term sequela seen after COVID-19 that can have a serious impact on the quality of life of patients. However, the pathogenesis of post-COVID-19 OD is still unclear, and there is no specific treatment for its patients. The aim of this paper was to review the research on OD caused by SARS-CoV-2 infection and to summarize the mechanism of action, the pathogenesis, and current treatments.

Comparative Analysis of Olfactory and Gustatory Function of Patients With COVID-19 Olfactory Dysfunction and Non-COVID-19 Postinfectious Olfactory Dysfunction

BACKGROUND

Coronavirus disease 2019 (COVID-19) is known to have a high incidence of loss of smell and taste. However, studies in the early stages of the COVID-19 pandemic have evaluated these symptoms using subjective surveys and simple olfactory tests only. Hence, we compared the olfactory and gustatory characteristics of patient groups with COVID-19 olfactory dysfunction (C19OD) and non-COVID-19 postinfectious olfactory dysfunction (PIOD) using an objective olfactory test and evaluated the significance of olfactory training in both patient groups.

METHODS

We retrospectively analyzed the medical records of 14 patients with a decreased sense of smell after having positive COVID-19 polymerase chain reaction results, and 56 patients with PIOD with no history of confirmed COVID-19. Participants were evaluated using the Korean version of the Sniffin' stick (KVSS) II, and chemical gustometry and olfactory training was assessed during their first visit. Olfactory training was then re-evaluated after an average of 8 (± 6) weeks.

RESULTS

The average age of participants in the C19OD group was lower than in those in the non-COVID-19 PIOD group. The proportion of men in the C19OD group was higher than in the non-COVID-19 PIOD group. At baseline assessment, the C19OD group had better olfactory and gustatory functions. After olfactory training, the non-COVID-19 PIOD patient group showed a significant increase in all KVSS II Total, T, D, and I scores, but there was a non-significant increase in all scores in the C19OD group.

CONCLUSION

The C19OD group had better olfactory and gustatory function than the non-COVID-19 PIOD group at the initial assessment. After olfactory training, there was an increase in olfactory function test scores in both groups. Olfactory training may be helpful in C19OD, as in non-COVID-19 PIOD.

Olfactory dysfunction among patients with COVID-19

OBJECTIVES

To assess the frequency of olfactory dysfunction (OD) among individuals afflicted with coronavirus disease of 2019 (COVID-19).

METHODS

A comprehensive literature search was carried out across several bibliographical databases (PubMed, Scopus, Google Scholar, and Web of Science) to extract publications in the English language between January 2020 and December 2021 to report the incidence of OD alone or together with gustatory dysfunction (GD) among COVID-19 patients.

RESULTS

Based on eligibility criteria, 84 articles were included from 27 countries, comprising 36,903 patients, of whom 58.1% were females. The generality rates of olfactory impairment alone was 34.60% and in conjunction with GD was 11.36%. Patients with OD were subclassified into various categories, and the prevalence of anosmia was 20.85%, 5.04% for hyposmia, 8.88% for anosmia or hyposmia, 1.84% for parosmia, 0.78% for phantosmia, and 0.02% for hyperosmia, among COVID-19 patients.

CONCLUSION

Clinical features associated with OD, either isolated or in combination with GD, are common in patients with COVID-19 and consider important signs of COVID-19 that may guide clinicians in the early phase of the disease.PROSPERO Reg. No.: 417296.

Vaccination against SARS-CoV-2 Does Not Protect against the Development of Anosmia in a Hamster Model

Anosmia, a total or partial loss of the ability to smell, is one of the most frequently documented sequelae of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Persistent anosmia is associated with a decrease in quality of life. Here, we assess the impact of virus lineage and vaccination status on anosmia development in the golden Syrian hamster model. To characterize anosmia driven by current variants, we assessed olfactory function in hamsters infected with SARS-CoV-2 lineages A, BA.2, BA.5, BQ.1, and BQ.1.1 using a buried food detection test. We found that significant anosmia occurs upon infection with all variants with a significant correlation between disease severity and degree of anosmia. Moreover, we found that vaccination with either the Pfizer (BNT16b2) or Moderna (mRNA-1273) mRNA vaccines does not protect against anosmia, despite protection against severe disease.

Prevalence of long-lasting loss of smell and taste after coronavirus disease 2019 infection in Saudi Arabia

BACKGROUND

People with coronavirus disease 2019 (COVID-19) who experience symptoms for more than 35 weeks are said to have long COVID. Anosmia can occur on its own or in combination with other COVID-19 symptoms. Anosmia may be a significant differential presentation for the suspicion and diagnosis of COVID-19 in patients with asymptomatic-to-mild COVID-19 disease and may disappear in 3 weeks. This study sought to determine the prevalence of persistent loss of taste and smell following COVID-19 in Saudi Arabia.

MATERIALS AND METHODS

A population-based cross-sectional study was conducted among Saudi citizens who had been diagnosed with COVID-19 for more than 2 weeks and had experienced a loss of taste and smell. Data was collected using a questionnaire having questions about demographics, long-lasting loss of taste and smell, whether this related to COVID-19 infection, and whether respondents had received the COVID-19 vaccine. SPSS was used for data analysis; statistical significance was determined using Chi-square test.

RESULTS

A total of 383 Saudis who had a history of COVID-19 participated in the study. About 43.3% study participants had experienced persistent loss of taste and smell after COVID-19 infection. A significant association was found between loss of smell and the region, Northern region having highest proportion of study participants who had loss of smell and Western region having the lowest prevalence (34%).

CONCLUSION

There were permanent changes in the sense of taste or smell in 34.3% of participants. This might add to the growing weight of long COVID.

Rapid point-of-care detection of SARS-CoV-2 infection in exhaled breath using ion mobility spectrometry: a pilot study

BACKGROUND

An effective testing strategy is essential for pandemic control of the novel Coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Breath gas analysis can expand the available toolbox for diagnostic tests by using a rapid, cost-beneficial, high-throughput point-of-care test. We conducted a bi-center clinical pilot study in Germany to evaluate breath gas analysis using multi-capillary column ion mobility spectrometry (MCC-IMS) to detect SARS-CoV-2 infection.

METHODS

Between September 23, 2020, and June 11, 2021, breath gas measurements were performed on 380 patients (SARS-CoV-2 real-time polymerase chain reaction (PCR) positive: 186; PCR negative: 194) presenting to the emergency department (ED) with respiratory symptoms.

RESULTS

Breath gas analysis using MCC-IMS identified 110 peaks; 54 showed statistically significant differences in peak intensity between the SARS-CoV-2 PCR-negative and PCR-positive groups. A decision tree analysis classification resulted in a sensitivity of 83% and specificity of 86%, but limited robustness to dataset changes. Modest values for the sensitivity (74%) and specificity (52%) were obtained using linear discriminant analysis. A systematic search for peaks led to a sensitivity of 77% and specificity of 67%; however, validation by transferability to other data is questionable.

CONCLUSIONS

Despite identifying several peaks by MCC-IMS with significant differences in peak intensity between PCR-negative and PCR-positive samples, finding a classification system that allows reliable differentiation between the two groups proved to be difficult. However, with some modifications to the setup, breath gas analysis using MCC-IMS may be a useful diagnostic toolbox for SARS-CoV-2 infection.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov on September 21, 2020 (NCT04556318; Study-ID: HC-N-H-2004).

Smell and Taste Loss Associated with COVID-19 Infection

OBJECTIVE

The aim of this study was to quantify the impact of COVID-19 on olfactory and gustatory function in US adults.

METHODS

From the 2021 Adult National Health Interview Survey, demographic and survey-specific module data concerning COVID-19 diagnoses, testing and disease severity, and data quantifying disturbances and eventual recovery of smell and taste were extracted. Sample weights were applied to obtain nationally representative statistics. The overall rate of COVID-19 infection was determined, and those diagnosed with COVID-19 were analyzed with respect to disease severity, smell and taste disturbance, and respective recoveries.

RESULTS

In 2021, 35.8 million or 14% of the adult population (95% CI 13.5-14.7%; mean age, 43.9 years; 53.8% female) had been diagnosed with COVID-19. Among those, 60.5% (58.6-62.5%) and 58.2% (56.2-60.1%) reported accompanying losses  in smell or taste, respectively; there was a significant association between overall COVID-19 symptom severity and smell (p < 0.001) and taste disturbance (p < 0.001). Following infection, 72.2% (69.9-74.3%), 24.1% (22.2-26.2%), and 3.7% (3.0-4.6%) of the patients experienced complete, partial, and no smell recovery, respectively. Recovery rates for gustatory function paralleled olfaction, with 76.8% (74.6-78.9%), 20.6% (18.7-22.7%), and 2.6 (1.9-3.4%) reporting complete, partial, and no recovery of taste, respectively. When sensory disturbance was present, severity of overall symptomatology was negatively associated with smell and taste recovery (p < 0.001 for each).

CONCLUSION

The majority of adults infected with COVID-19 in 2021 experienced olfactory or gustatory dysfunction with a non-negligible population reporting incomplete or no near-term sensory recovery. Our results are useful for providers counseling patients and suggest that interventions lessening overall COVID-19 symptom burden may prevent prolonged sensory dysfunction.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2357-2361, 2023.

Neurological complications and effects of COVID-19: Symptoms and conceivable mechanisms

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in December 2019 in Wuhan, China. The new coronavirus disease (COVID-19) was declared a global pandemic by the World Health Organization (WHO) in March 2020. SARS-CoV-2 can invade the nervous system aside from infecting the respiratory system as its primary target. The most common nervous system symptoms of COVID-19 are stated as headache, myalgia, fatigue, nausea, vomiting, sudden and unexplained anosmia, and ageusia. More severe conditions such as encephalomyelitis, acute myelitis, thromboembolic events, ischemic stroke, intracerebral hemorrhage, Guillain-Barré-syndrome, Bell's palsy, rhabdomyolysis, and even coma have also been reported. Cohort studies revealed that neurological findings are associated with higher morbidity and mortality. The neurological symptoms and manifestations caused by SARS-CoV-2 and COVID-19 are examined and summarized in this article.

Effect of any form of steroids in comparison with that of other medications on the duration of olfactory dysfunction in patients with COVID-19: A systematic review of randomized trials and quasi-experimental studies

BACKGROUND

The life quality of about two-thirds of patients with COVID-19 is affected by related olfactory dysfunctions. The negative impact of olfactory dysfunction ranged from the decreased pleasure of eating to impaired quality of life. This research aimed to provide a comprehensive understanding of the effects of corticosteroid treatments by comparing that to other currently available treatments and interventions.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist's 27-point checklist was used to conduct this review. PubMed (Public/Publisher MEDLINE), PubMed Central and EMBASE (Excerpta Medica Database) databases were conveniently selected and Boolean search commands were used for a comprehensive literature search. Five core search terms were "effects of treatments", " COVID-19-related olfactory dysfunction", "corticosteroids", "treatments" and "interventions". The reporting qualities of the included studies were appraised using JBI (Joanna Briggs Institute) appraisal tools. The characteristics of the 21 experimental studies with a total sample (of 130,550) were aggregated using frequencies and percentages and presented descriptively. The main interventions and their effects on the duration of the COVID-19-related olfactory dysfunction were narratively analyzed.

RESULTS

Among patients with COVID-19, the normal functions of the olfactory lobe were about 23 days earlier to gain with the treatments of fluticasone and triamcinolone acetonide nasal spray compared with that of mometasone furoate nasal spray and oral corticosteroid. The smell loss duration was reduced by fluticasone and triamcinolone acetonide nasal spray 9 days earlier than the inflawell syrup and 16 days earlier than the lavender syrup. The nasal spray of corticosteroids ended the COVID-19-related smell loss symptoms 2 days earlier than the zinc supplementation, about 47 days earlier than carbamazepine treatment and was more effective than palmitoylethanolamide (PEA) and luteolin and omega-3 supplementations and olfactory training. Treatment with oral corticosteroid plus olfactory training significantly improved Threshold, Discrimination and Identification (TDI) scores compared with olfactory training alone. A full dose of the COVID-19 vaccination was not uncertain to reduce the COVID-19-related smell loss duration.

CONCLUSION

Corticosteroid treatment is effective in reducing the duration of COVID-19-related smell loss and olfactory training, the basic, essential and effective intervention, should be used as a combination therapy.

Can photobiomodulation restore anosmia and ageusia induced by COVID-19? A pilot clinical study

Along with other COVID-19 clinical manifestations, management of both olfactory and gustatory dysfunction have drawn a considerable attention. Photobiomodulation (PBM) has emerged to be a possible effective therapy in restoring taste and smell functionality, but the evidence is scarce. Hence, the present pilot study is aimed to evaluate the effectiveness of intranasal and intraoral PBM administrations in management of anosmia and ageusia respectively. Twenty Caucasian subjects who diagnosed with anosmia and ageusia were recruited. Visual analogue scale was utilised to evaluate patients' self-reported for both olfactory and gustatory functionality. The laser-PBM parameters and treatment protocols for anosmia and ageusia were as follows respectively: 660 nm, 100 mW, two points intranasally, 60 J/session, 12 sessions; dual wavelengths (660 nm and 808 nm), 100 mW, three points intraorally, 216 J/session, 12 sessions. Our results showed a significant functionality improvement of both olfactory and gustatory functionality. Extensive studies with large data and long-term follow-up period are warranted.

Olfactory Function and Olfactory Disorders

The sense of smell is important. This became especially clear to patients with infection-related olfactory loss during the SARS-CoV-2 pandemic. We react, for example, to the body odors of other humans. The sense of smell warns us of danger, and it allows us to perceive flavors when eating and drinking. In essence, this means quality of life. Therefore, anosmia must be taken seriously. Although olfactory receptor neurons are characterized by regenerative capacity, anosmia is relatively common with about 5 % of anosmic people in the general population. Olfactory disorders are classified according to their causes (e. g., infections of the upper respiratory tract, traumatic brain injury, chronic rhinosinusitis, age) with the resulting different therapeutic options and prognoses. Thorough history taking is therefore important. A wide variety of tools are available for diagnosis, ranging from short screening tests and detailed multidimensional test procedures to electrophysiological and imaging methods. Thus, quantitative olfactory disorders are easily assessable and traceable. For qualitative olfactory disorders such as parosmia, however, no objectifying diagnostic procedures are currently available. Therapeutic options for olfactory disorders are limited. Nevertheless, there are effective options consisting of olfactory training as well as various additive drug therapies. The consultation and the competent discussion with the patients are of major importance.

Neuroimaging of COVID-19

We review the wide variety of common neuroimaging manifestations related to coronavirus disease 2019 (COVID-19) and COVID therapies, grouping the entities by likely pathophysiology, recognizing that the etiology of many entities remains uncertain. Direct viral invasion likely contributes to olfactory bulb abnormalities. COVID meningoencephalitis may represent direct viral infection and/or autoimmune inflammation. Para-infectious inflammation and inflammatory demyelination at the time of infection are likely primary contributors to acute necrotizing encephalopathy, cytotoxic lesion of the corpus callosum, and diffuse white matter abnormality. Later postinfectious inflammation and demyelination may manifest as acute demyelinating encephalomyelitis, Guillain-Barré syndrome, or transverse myelitis. The hallmark vascular inflammation and coagulopathy of COVID-19 may produce acute ischemic infarction, microinfarction contributing to white matter abnormality, space-occupying hemorrhage or microhemorrhage, venous thrombosis, and posterior reversible encephalopathy syndrome. Adverse effects of therapies including zinc, chloroquine/hydroxychloroquine, antivirals, and vaccines, and current evidence regarding "long COVID" is briefly reviewed. Finally, we present a case of bacterial and fungal superinfection related to immune dysregulation from COVID.

Post-COVID Parosmia in Women May be Associated with Low Estradiol Levels

We aimed to investigate the effects of female gender hormones on post-COVID parosmia in females. Twenty-three female patients aged 18-45 who had COVID-19 disease in the last 12 months were included in the study. Estradiol (E2), prolactin (PRL), luteotrophic hormone (LH), follicular stimulating hormone (FSH), and thyroid stimulating hormone (TSH) values were measured in the blood of all participants and a parosmia questionnaire was applied for the subjective evaluation of olfactory function. Values between 4 and 16 were obtained as parosmia score (PS), and the lowest PS showed the most severe complaint. The mean age of the patients was 31 (18-45). According to the PS, patients with a score of 10 or less were classified as Group 1, and patients above 10 were considered Group 2. The age difference between Groups 1 and 2 was statistically significant and younger patients were found to have more complaints of parosmia (25 and 34, respectively, p-value 0.014). It was found that patients with severe parosmia had lower E2 values and there was a statistically significant difference (p-value 0.042) between groups 1 and 2 in terms of E2 values (34 ng/L and 59 ng/L, respectively). There was no significant difference between the two groups in terms of PRL, LH, FSH, TSH levels, or FSH/LH ratio. It may be recommended to measure E2 values in female patients whose parosmia continues after COVID-19 infection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03612-9.

Setting up a three‐stage pre‐endoscopy triage during the coronavirus disease 2019 pandemic: A multicenter observational study

Objectives

Between May and July 2021, the coronavirus disease 2019 (COVID‐19) pandemic led to a sharp surge in community transmission in Taiwan. We present a three‐stage restructuring process of pre‐endoscopy triage at the beginning of the pandemic, which can support urgent endoscopic procedures while protecting endoscopy staff.

Methods

The pre‐endoscopy triage framework was set up with three checkpoints at the hospital entrance, outpatient department, and endoscopy unit, with a specific target patient population and screening methods. Relevant data included the number of endoscopic procedures performed, outpatient department visits, and performing screening methods such as temperature measurement, travel, occupation, contact, and clustering history checking, polymerase chain reaction assay, and rapid antigen test.

Results

Forehead temperature measurement and verification of travel, occupation, contact, and clustering history provided rapid, easy, and early mass screening of symptomatic patients at the hospital entrance. During the pandemic, outpatient department visits and endoscopic procedures decreased by 37% and 64%, respectively. The pre‐endoscopy screening methods used displayed regional variations in COVID‐19 prevalence. Among 16 endoscopy units with a community prevalence of ≥ 31.04 cases per 100,000 residents, 12 (75%) used polymerase chain reaction assay and four (25%) used rapid antigen test to identify asymptomatic patients before endoscopy. Of 6540 pre‐endoscopy screening patients, 15 (0.23%) tested positive by laboratory testing. No endoscopy‐related nosocomial COVID‐19 infections were reported during the pandemic.

Conclusions

We present a three‐stage pre‐endoscopy triage based on the local laboratory capacity, medical resources, and community prevalence. These measures could be useful during the COVID‐19 pandemic.

Aberrant olfactory network functional connectivity in people with olfactory dysfunction following COVID-19 infection: an exploratory, observational study

BACKGROUND

Olfactory impairments and anosmia from COVID-19 infection typically resolve within 2-4 weeks, although in some cases, symptoms persist longer. COVID-19-related anosmia is associated with olfactory bulb atrophy, however, the impact on cortical structures is relatively unknown, particularly in those with long-term symptoms.

METHODS

In this exploratory, observational study, we studied individuals who experienced COVID-19-related anosmia, with or without recovered sense of smell, and compared against individuals with no prior COVID-19 infection (confirmed by antibody testing, all vaccine naïve). MRI Imaging was carried out between the 15th July and 17th November 2020 at the Queen Square House Clinical Scanning Facility, UCL, United Kingdom. Using functional magnetic resonance imaging (fMRI) and structural imaging, we assessed differences in functional connectivity (FC) between olfactory regions, whole brain grey matter (GM) cerebral blood flow (CBF) and GM density.

FINDINGS

Individuals with anosmia showed increased FC between the left orbitofrontal cortex (OFC), visual association cortex and cerebellum and FC reductions between the right OFC and dorsal anterior cingulate cortex compared to those with no prior COVID-19 infection (p < 0.05, from whole brain statistical parametric map analysis). Individuals with anosmia also showed greater CBF in the left insula, hippocampus and ventral posterior cingulate when compared to those with resolved anosmia (p < 0.05, from whole brain statistical parametric map analysis).

INTERPRETATION

This work describes, for the first time to our knowledge, functional differences within olfactory areas and regions involved in sensory processing and cognitive functioning. This work identifies key areas for further research and potential target sites for therapeutic strategies.

FUNDING

This study was funded by the National Institute for Health and Care Research and supported by the Queen Square Scanner business case.

Prevalence of taste and smell dysfunction in mild and asymptomatic COVID-19 patients during Omicron prevalent period in Shanghai, China: a cross-sectional survey study

OBJECTIVES

COVID-19, which is caused by SARS-CoV-2, is a severe threat to human health and the economy globally. This study aimed to investigate the prevalence of taste and/or smell dysfunction and associated risk factors in mild and asymptomatic patients with Omicron infection in Shanghai, China.DesignThis was a questionnaire-based cross-sectional study.

SETTING

COVID-19 patients at the makeshift hospital in the Shanghai World Expo Exhibition and Convention Centre were recruited from March to April 2022.

PARTICIPANTS

In total, 686 COVID-19-infected patients who were defined as mild or asymptomatic cases according to the diagnostic criteria of New Coronavirus Pneumonia Prevention and Control Programme ninth edition (National Health Commission of China, 2022) were enrolled.

MEASURES

Data to investigate taste and smell loss and to characterise other symptoms were collected by the modified Chemotherapy-induced Taste Alteration Scale and Sino-Nasal Outcome Test-22 questionnaires. The risk factors for the severity of taste/smell dysfunction were analysed by binary logistic regression models.

RESULTS

379 males (379/686, 55.2%) and 307 females (307/686, 44.8%) completed the questionnaires to record recent changes in taste and smell ability. A total of 302 patients (44%) had chemosensory dysfunction with Omicron infection, of which 22.7% (156/686) suffered from both taste and smell dysfunction. In addition, cough (60.2%), expectoration (40.5%), fever (33.2%) and sore throat (32.5%) were common symptoms during Omicron infection. The quality-of-life-related indicators were negatively associated with participants' self-reported taste and smell dysfunction.

CONCLUSIONS

The prevalence of taste or/and smell dysfunction in patients with Omicron infections was 44%. Individuals with chemosensory dysfunction had significantly higher rates of various upper respiratory influenza-like symptoms, xerostomia and bad breath. Moreover, smell dysfunction was a risk factor for the prevalence of taste dysfunction in patients with Omicron infection.

TRIAL REGISTRATION NUMBER

ChiCTR 2200059097.

Characterization of otologic symptoms appearing after COVID-19 vaccination

OBJECTIVES

Anecdotal reports of sudden sensorineural hearing loss (SSNHL) following COVID-19 vaccination have emerged in the otolaryngology community. Studies have demonstrated no association between COVID-19 vaccination and SSNHL. We aim to characterize the spectrum of otologic symptoms following COVID-19 vaccination.

METHODS

A cross-sectional study of patients seen in the otology clinic at an academic center was performed. Patients completed a questionnaire on the development of new otologic symptoms within 4 weeks of COVID-19 vaccination. Diagnostic and audiometric data was collected retrospectively for patients reporting otologic symptoms.

RESULTS

Between May and July 2021, 500 patients were screened. Median age was 56.6 years old, with 59.4 % female and 40.2 % male. 420 patients (84.0 %) were vaccinated, with 58.4 % receiving Pfizer, 29.1 % receiving Moderna, and 3.8 % receiving Johnson & Johnson. 61 patients (14.5 %) reported one or more otologic symptoms within 4 weeks of vaccination, including 21 (5.0 %) with hearing loss, 26 (6.2 %) with tinnitus, 33 (7.9 %) with dizziness, and 19 (4.5 %) with vertigo. Of the 16 patients (3.2 %) reporting tinnitus with no associated hearing loss, 8 were diagnosed with subjective tinnitus and 4 were diagnosed with temporomandibular joint syndrome. Of the 18 patients reporting hearing loss, 11 had exacerbations of underlying pathologies (e.g. Meniere's disease, presbycusis) and 7 were newly diagnosed with SSNHL (1.4 %).

CONCLUSIONS

Patients reporting otologic symptoms following COVID-19 vaccination received various diagnoses of uncertain etiology. The incidence of SSNHL in these patients is comparable to the general otology patient population. Additional studies are required to determine the incidence of specific diagnoses following vaccination.

Two Cases of Familial Mediterranean Fever Involving MEFV Variants: The Importance of Differentiating the Diagnosis from COVID-19

Familial Mediterranean fever (FMF) is an inherited autoinflammatory disease associated with the MEFV gene. FMF is common in Mediterranean peoples but not highly recognized in Japan. We herein report two cases of Japanese FMF patients who were diagnosed by genetic testing for the MEFV gene during the coronavirus disease 2019 (COVID-19) pandemic. Both patients presented with symptoms similar to COVID-19, which delayed the definitive diagnosis. Patients with a confirmed diagnosis of FMF may be eligible for physical, emotional, and financial benefits. Therefore, the COVID-19 pandemic highlights the importance of differentiating the diagnosis by genetic testing.

Associations of Country-Specific and Sociodemographic Factors With Self-Reported COVID-19-Related Symptoms: Multivariable Analysis of Data From the CoronaCheck Mobile Health Platform

BACKGROUND

The COVID-19 symptom-monitoring apps provide direct feedback to users about the suspected risk of infection with SARS-CoV-2 and advice on how to proceed to prevent the spread of the virus. We have developed the CoronaCheck mobile health (mHealth) platform, the first free app that provides easy access to valid information about the risk of infection with SARS-CoV-2 in English and German. Previous studies have suggested that the clinical characteristics of individuals infected with SARS-CoV-2 vary by age, gender, and viral variant; however, potential differences between countries have not been adequately studied.

OBJECTIVE

The aim of this study is to describe the characteristics of the users of the CoronaCheck mHealth platform and to determine country-specific and sociodemographic associations of COVID-19-related symptoms and previous contacts with individuals infected with COVID-19.

METHODS

Between April 8, 2020, and February 3, 2022, data on sociodemographic characteristics, symptoms, and reports of previous close contacts with individuals infected with COVID-19 were collected from CoronaCheck users in different countries. Multivariable logistic regression analyses were performed to examine whether self-reports of COVID-19-related symptoms and recent contact with a person infected with COVID-19 differed between countries (Germany, India, South Africa), gender identities, age groups, education, and calendar year.

RESULTS

Most app users (N=23,179) were from Germany (n=8116, 35.0%), India (n=6622, 28.6%), and South Africa (n=3705, 16.0%). Most data were collected in 2020 (n=19,723, 85.1%). In addition, 64% (n=14,842) of the users were male, 52.1% (n=12,077) were ≥30 years old, and 38.6% (n=8953) had an education level of more than 11 years of schooling. Headache, muscle pain, fever, loss of smell, loss of taste, and previous contacts with individuals infected with COVID-19 were reported more frequently by users in India (adjusted odds ratios [aORs] 1.3-8.3, 95% CI 1.2-9.2) and South Africa (aORs 1.1-2.6, 95% CI 1.0-3.0) than those in Germany. Cough, general weakness, sore throat, and shortness of breath were more frequently reported in India (aORs 1.3-2.6, 95% CI 1.2-2.9) compared to Germany. Gender-diverse users reported symptoms and contacts with confirmed COVID-19 cases more often compared to male users.

CONCLUSIONS

Patterns of self-reported COVID-19-related symptoms and awareness of a previous contact with individuals infected with COVID-19 seemed to differ between India, South Africa, and Germany, as well as by gender identity in these countries. Viral symptom-collecting apps, such as the CoronaCheck mHealth platform, may be promising tools for pandemics to support appropriate assessments. Future mHealth research on country-specific differences during a pandemic should aim to recruit representative samples.

Olfactory and Gustatory Dysfunction in COVID-19: A Global Bibliometric and Visualized Analysis

OBJECTIVES

Coronavirus illness (COVID-19) has been found to alter infected people's sense of smell and taste. However, the pathobiology of this virus is not yet known. Therefore, it is critical to investigate the influence of COVID-19 infection on olfactory and gustatory processes. Therefore, we use bibliometric analysis on COVID-19 and olfactory and/or gustatory dysfunction publications to provide studies perspective.

METHODS

A bibliometric literature search was performed in the Scopus database. The number and type of publications, countries for publications, institutional sources for publications, journals for publications, citation patterns, and funding agencies were analyzed using Microsoft Excel or VOSviewer. In addition, the VOSviewer 1.6.17 software was used to analyze and visualize hotspots and collaboration patterns between countries.

RESULTS

Scopus has published 187 088 documents for COVID-19 in all study fields at the time of data collection (July 26, 2021). A total of 1740 documents related to olfactory and/or gustatory dysfunction were recovered. The countries most relevant by the number of publications were the United States (n = 362, 20.80%), Italy (n = 255, 14.66%), and the United Kingdom (n = 173, 9.94%). By analyzing the terms in the titles and abstracts, we identified 2 clusters related to olfactory and/or gustatory dysfunction research, which are "diagnosis and test methods" and "prognosis and complications of the disease."

CONCLUSIONS

This is the first bibliometric analysis of publications related to COVID-19 and olfactory and/or gustatory dysfunction. This study provides academics and researchers with useful information on the publishing patterns of the most influential publications on COVID-19 and olfactory and/or gustatory dysfunction. Olfactory and/or gustatory dysfunction as indices of suspicion for the empirical diagnosis of coronavirus infection is a new hotspot in this field.

Nutritional problems of patients with COVID-19 receiving dietetic treatment in primary care

BACKGROUND

The nutritional problems of patients who are hospitalised for COVID-19 are becoming increasingly clear. However, a large group of patients have never been hospitalised and also appear to experience persistent nutritional problems. The present study describes the nutritional status, risk of sarcopaenia and nutrition-related complaints of patients recovering from COVID-19 receiving dietetic treatment in primary care.

METHODS

In this retrospective observational study, data were collected during dietetic treatment by a primary care dietitian between April and December 2020. Both patients who had and had not been admitted to the hospital were included at their first visit to a primary care dietitian. Data on nutritional status, risk of sarcopaenia and nutrition-related complaints were collected longitudinally.

RESULTS

Data from 246 patients with COVID-19 were collected. Mean ± SD age was 57 ± 16 years and 61% of the patient population was female. At first consultation, two thirds of patients were classified as overweight or obese (body mass index >25 kg m-2 ). The majority had experienced unintentional weight loss because of COVID-19. Additionally, 55% of hospitalised and 34% of non-hospitalised patients had a high risk of sarcopaenia. Most commonly reported nutrition-related complaints were decreased appetite, shortness of breath, changed or loss of taste and feeling of being full. Nutrition-related complaints decreased after the first consultation, but remained present over time.

CONCLUSIONS

In conclusion, weight changes, risk of sarcopaenia and nutrition-related complaints were prevalent in patients with COVID-19, treated by a primary care dietitian. Nutrition-related complaints improved over time, but remained prevalent until several months after infection.

European Working Group on SARS-CoV-2: Current Understanding, Unknowns, and Recommendations on the Neurological Complications of COVID-19

The emergence of COVID-19 was rapidly followed by infection and the deaths of millions of people across the globe. With much of the research and scientific advancement rightly focused on reducing the burden of severe and critical acute COVID-19 infection, the long-term effects endured by those who survived the acute infection has been previously overlooked. Now, an appreciation for the post-COVID-19 condition, including its neurological manifestations, is growing, although there remain many unknowns regarding the aetiology and risk factors of the condition, as well as how to effectively diagnose and treat it. Here, drawing upon the experiences and expertise of the clinicians and academics of the European working group on COVID-19, we have reviewed the current literature to provide a comprehensive overview of the neurological sequalae of the post-COVID-19 condition. In this review, we provide a summary of the neurological symptoms associated with the post-COVID-19 condition, before discussing the possible mechanisms which may underly and manifest these symptoms. Following this, we explore the risk factors for developing neurological symptoms as a result of COVID-19 and the post-COVID-19 condition, as well as how COVID-19 infection may itself be a risk factor for the development of neurological disease in the future. Lastly, we evaluate how the post-COVID condition could be accurately diagnosed and effectively treated, including examples of the current guidelines, clinical outcomes and tools that have been developed to aid in this process, as well as addressing the protection provided by COVID-19 vaccines against post-COVID-19 condition. Overall, this review provides a comprehensive overview of the neurological sequalae of the post-COVID-19 condition.

Medical Face Masks Do Not Affect Acid-Base Balance Yet Might Facilitate the Transmission of Staphylococcus aureus in Hospital Settings during the COVID-19 Pandemic

INTRODUCTION

Due to the SARS-CoV-2 coronavirus pandemic, the wearing of masks has become a common phenomenon. Most of the undesirable effects of using a protective face covering are usually related to the prolonged time of its wearing, and the adverse consequences of face coverings should be considered two-fold. The aim of the study was to evaluate the rate of contamination of the three types of face coverings (surgical, N95, and FFP2 masks) with the microorganism-aerobic bacteria, yeasts, and molds-after the 3 h exposure time. The study aimed to investigate the effects of wearing FFP2 masks (KN95) on respiratory function and the acid-base balance of the human body.

RESULTS

The presence of S. aureus was confirmed in both nasal carriers and non-carriers which may demonstrate the cross-contamination and spread of this bacterium via hands. S. aureus was found on external and internal surfaces of face masks of each type, and therefore could also be transmitted via hands from external sources. The 3 h exposure time is not sufficient for Gram-negative rods and mold contamination. Moreover, there were no significant differences in most of the parameters studied between the first and second examinations, both in spirometry and capillary blood gas analysis (p > 0.05).

Olfactory and taste dysfunction in COVID-19-incidence and recovery

Background

Olfactory and taste dysfunctions have been identified as prominent signs of COVID-19 infection. The data on its prevalence, time of onset, and recovery is highly variable.

Objective

The study was aimed at establishing the incidence of and the factors influencing smell and taste disorders in COVID-19-affected patients.

Methodology

Telephonic interviews were used to collect data on the symptoms of COVID-19-positive patients, with an emphasis on smell and taste disorders. Patients have severe disease and a history of illnesses that may affect olfaction or taste, and those unwilling to participate were excluded.

Results

A total of 1488 COVID-19-positive patients were identified. A total of 772 were included and interviewed, and their data were analysed. A total of 242 (31.3%) patients developed symptoms related to smell and/or taste. Anosmia (149) and ageusia (152) were the most common. Younger patients were more commonly affected (p = 0.0016). The presence and degree of smell symptoms and taste symptoms showed a small positive correlation (r = .234, p < .001). A strong relationship was seen with fever (r = .825, p < .001) and a significantly moderate relationship with breathing difficulty. There was no significant difference based on age or sex for the recovery of smell or taste sensations. There was a significant correlation between taste recovery and smell recovery times (p < 0.00001).

Conclusion

Smell and taste disorders, as early clinical symptoms of COVID-19, may have a diagnostic as well as a prognostic value. Treatment protocols for these patients are yet to be defined. A positive association between these symptoms and breathing difficulty was found, and we recommend COVID-19 testing and monitoring of symptoms for all patients with new-onset OTD symptoms. A combination of active enquiry about these symptoms, along with objective testing when the patients present with COVID-19 symptoms may help in better understanding of the pathophysiology and timely initiation of treatment.

Is the post-COVID-19 syndrome a severe impairment of acetylcholine-orchestrated neuromodulation that responds to nicotine administration?

Following a SARS-CoV-2 infection, many individuals suffer from post-COVID-19 syndrome. It makes them unable to proceed with common everyday activities due to weakness, memory lapses, pain, dyspnea and other unspecific physical complaints. Several investigators could demonstrate that the SARS-CoV-2 related spike glycoprotein (SGP) attaches not only to ACE-2 receptors but also shows DNA sections highly affine to nicotinic acetylcholine receptors (nAChRs). The nAChR is the principal structure of cholinergic neuromodulation and is responsible for coordinated neuronal network interaction. Non-intrinsic viral nAChR attachment compromises integrative interneuronal communication substantially. This explains the cognitive, neuromuscular and mood impairment, as well as the vegetative symptoms, characterizing post-COVID-19 syndrome. The agonist ligand nicotine shows an up to 30-fold higher affinity to nACHRs than acetylcholine (ACh). We therefore hypothesize that this molecule could displace the virus from nAChR attachment and pave the way for unimpaired cholinergic signal transmission. Treating several individuals suffering from post-COVID-19 syndrome with a nicotine patch application, we witnessed improvements ranging from immediate and substantial to complete remission in a matter of days.

Loss of Sour Taste Is the Striking Feature among Four Basic Taste Qualities in Tunisian COVID-19 Patients

BACKGROUND

Taste disorders (TDs) have been reported to be very common in patients suffering from coronavirus disease 2019 (COVID-19), which is caused by the SARS-CoV-2 virus. In most of the hitherto conducted studies, a gustatory assessment was performed on the basis of surveys or self-reports by patients. The aim of our study was to undertake an objective assessment of four basic taste qualities by conducting tasting sessions that allowed detection thresholds in COVID-19 Tunisian patients and to study their associations with inflammation.

METHODS

This analytical cross-sectional study was conducted on 89 patients aged between 21 to 70 years who had been diagnosed with COVID-19. We used Burghart taste strips to assess taste perception of the four taste qualities, i.e., sour, bitter, sweet, and salty. Serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and C-reactive protein (CRP) were measured.

RESULTS

Taste disorders were reported by 40.4% of the patients, while objective assessments revealed that 63.8% of participants were suffering from hypogeusia and/or ageusia. Sour taste was the most altered (70.8%) gustatory quality. Patients with severe COVID-19 had significantly lower sour and bitter taste scores when compared to patients with minor/moderate forms. There was no significant association between serum inflammatory markers and taste disorders. However, the relationship between bitter and sweet taste qualities and IL-1β levels was significant (p = 0.018 and p = 0.041).

CONCLUSIONS

Our results demonstrate the interest in the objective assessment of taste dysfunctions in COVID-19 patients.

Lithium-Induced Dysgeusia and Hyposmia: A Case Report and a Literature Review

BACKGROUND

Bipolar disorder is a complex psychiatric disorder where long-term treatment is crucial to maintain stabilization. Although largely well tolerated, lithium has a wide spectrum of adverse effects in different organs and seems to also cause taste and smell disorders, which remain rare and not largely described. We aim to present a rare case of hyposmia and dysgeusia secondary to lithium treatment in a bipolar patient and also conduct a review on these rare lithium adverse effects.

CASE PRESENTATION

The case is a 43-year-old woman with type I bipolar disorder who became stabilized and fully functional with lithium therapy. After 4 months of treatment, she began to notice progressive hyposmia and dysgeusia. After multiple diagnostic and screening tests, lithium was implicated as the cause of the symptoms, which led to a switch to valproic acid. After 3 months, she was not compensated with valproic acid treatment, returned to lithium therapy despite its adverse effects, and became stabilized again.

CONCLUSIONS

There are few data on lithium therapy taste and smell adverse effects. Most studies on this topic are likely to be case reports. Lithium therapy may cause dysgeusia and hyposmia, although mechanisms are not fully understood. These adverse effects can interfere negatively in patient's treatment adherence. Therefore, physicians who prescribe lithium should be aware of them. Further structured studies are needed to better understand these lithium rare adverse effects and the appropriate way to assess and monitoring them.

Pathophysiology of SARS-CoV-2 Infection of Nasal Respiratory and Olfactory Epithelia and Its Clinical Impact

PURPOSE OF REVIEW

While the predominant cause for morbidity and mortality with SARS-CoV-2 infection is the lower respiratory tract manifestations of the disease, the effects of SARS-CoV-2 infection on the sinonasal tract have also come to the forefront especially with the increased recognition of olfactory symptom. This review presents a comprehensive summary of the mechanisms of action of the SARS-CoV-2 virus, sinonasal pathophysiology of COVID-19, and the correlation with the clinical and epidemiological impact on olfactory dysfunction.

RECENT FINDINGS

ACE2 and TMPRSS2 receptors are key players in the mechanism of infection of SARS-CoV-2. They are present within both the nasal respiratory as well as olfactory epithelia. There are however differences in susceptibility between different groups of individuals, as well as between the different SARS-CoV-2 variants. The sinonasal cavity is an important route for SARS-CoV-2 infection. While the mechanism of infection of SARS-CoV-2 in nasal respiratory and olfactory epithelia is similar, there exist small but significant differences in the susceptibility of these epithelia and consequently clinical manifestations of the disease. Understanding the differences and nuances in sinonasal pathophysiology in COVID-19 would allow the clinician to predict and counsel patients suffering from COVID-19. Future research into molecular pathways and cytokine responses at different stages of infection and different variants of SARS-CoV-2 would evaluate the individual clinical phenotype, prognosis, and possibly response to vaccines and therapeutics.

Taste loss as a distinct symptom of COVID-19: a systematic review and meta-analysis

Chemosensory scientists have been skeptical that reports of COVID-19 taste loss are genuine, in part because before COVID-19 taste loss was rare and often confused with smell loss. Therefore, to establish the predicted prevalence rate of taste loss in COVID-19 patients, we conducted a systematic review and meta-analysis of 376 papers published in 2020-2021, with 235 meeting all inclusion criteria. Drawing on previous studies and guided by early meta-analyses, we explored how methodological differences (direct vs. self-report measures) may affect these estimates. We hypothesized that direct measures of taste are at least as sensitive as those obtained by self-report and that the preponderance of evidence confirms taste loss is a symptom of COVID-19. The meta-analysis showed that, among 138,015 COVID-19-positive patients, 36.62% reported taste dysfunction (95% confidence interval: 33.02%-40.39%), and the prevalence estimates were slightly but not significantly higher from studies using direct (n = 15) versus self-report (n = 220) methodologies (Q = 1.73, df = 1, P = 0.1889). Generally, males reported lower rates of taste loss than did females, and taste loss was highest among middle-aged adults. Thus, taste loss is likely a bona fide symptom of COVID-19, meriting further research into the most appropriate direct methods to measure it and its underlying mechanisms.

Clinical manifestations of COVID-19 versus other upper respiratory tract infections in pediatric patients

OBJECTIVES

To explore the differences between COVID-19 and upper respiratory tract infections (URTI) in the pediatric population, emphasizing smell and taste disturbances.

METHODS

A case-control study included 468 patients, 234 with COVID-19 (cases) and 234 with URTI (controls) at a tertiary hospital, Riyadh, Saudi Arabia, from 2020-2021. Patients with bacterial URTI, lower tract respiratory infections, and speech or developmental delays were excluded. Statistical analysis was carried out using Statistical Analysis System, 9.2 version. A p-value of ≤0.05 was considered significant.

RESULTS

The male-to-female ratio was almost equal, with a mean age of 9.90±2.34. Multivariable logistic regression analysis showed that a change in taste significantly increases the probability of COVID-19 by 21.98 times. On the other hand, sore throat (81.5%), dyspnea (63.5%), nasal obstruction (72.7%), and otalgia significantly (74.8%) decrease the likelihood of COVID-19.

CONCLUSION

Taste disturbances increase the probability of COVID-19 infections, whereas sore throat, dyspnea, nasal obstruction, and otalgia increase the likelihood of other URTIs. The described differences might aid physicians in their differential diagnosis and treatment during the pandemic.