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Journal of Neurovirology Feb 2023Clinical manifestations of human coronavirus (HCoV)-related diseases are mostly related to the respiratory system, although secondary complications such as headache,...
Clinical manifestations of human coronavirus (HCoV)-related diseases are mostly related to the respiratory system, although secondary complications such as headache, anosmia, ageusia, and myalgia have been reported. HCoV infection and replication in chemosensory cells associated with ageusia and anosmia is poorly understood. Here, we characterized HCoV-OC43 and SARS-CoV-2 infection in two types of chemosensory cells, olfactory and taste cells, with their unique molecular and histological characteristics. We first assessed HCoV-OC43 infection in in vitro cultured human olfactory epithelial cells (hOECs) and fungiform taste papilla (HBO) cells. Interestingly, while both cell types were susceptible to HCoV-OC43 infection, viral replication rates were significantly reduced in HBO cells compared to hOECs. More interestingly, while culture media from hOECs was able to produce secondary infection in Vero cells, there was very limited secondary infection from HBO cells, suggesting that HBO cells may not be able to release infectious virus. On the other hand, unlike HCoV-OC43, SARS-CoV-2 showed comparable levels of viral infection rates in both hOECs and HBO cells. Furthermore, our RT-qPCR-based gene array studies revealed that several key genes involved in taste and olfactory functions were significantly altered by SARS-CoV-2 infection. These results may suggest a possible mechanism associated with chemosensory symptoms, such as anosmia and ageusia in patients infected with SARS-CoV-2.
Topics: Animals; Chlorocebus aethiops; Humans; COVID-19; Vero Cells; Ageusia; Anosmia; Coinfection; SARS-CoV-2; Coronavirus OC43, Human
PubMed: 36719595
DOI: 10.1007/s13365-023-01117-3 -
AJNR. American Journal of Neuroradiology Jan 2021
Topics: Anosmia; COVID-19; Humans; Magnetic Resonance Imaging; Olfactory Bulb; SARS-CoV-2
PubMed: 33272952
DOI: 10.3174/ajnr.A6943 -
Autoimmunity Reviews Dec 2020
Topics: Angiotensin-Converting Enzyme 2; Anosmia; Autoantibodies; Autoimmune Diseases; COVID-19; COVID-19 Vaccines; Cytokine Release Syndrome; HLA Antigens; Humans; Hyperferritinemia; SARS-CoV-2
PubMed: 33130000
DOI: 10.1016/j.autrev.2020.102695 -
Laryngo- Rhino- Otologie May 2023The 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 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.
Topics: Humans; Anosmia; Quality of Life; SARS-CoV-2; COVID-19; Olfaction Disorders
PubMed: 37130532
DOI: 10.1055/a-1957-3267 -
Journal of the Neurological Sciences Jun 2021Olfaction, one of our five main qualitative sensory abilities, is the action of smelling or the capacity to smell. Olfactory impairment can be a sign of a medical... (Review)
Review
Olfaction, one of our five main qualitative sensory abilities, is the action of smelling or the capacity to smell. Olfactory impairment can be a sign of a medical problem, from a benign nasal/sinus problem up to a potentially serious brain injury. However, although clinicians (neurologists or not) usually test the olfactory nerves in specific clinical situations (for example, when a neurodegenerative disorder is suspected), they may omit such tests in many other situations. With the recent COVID-19 pandemic, the resurgence of anosmia has reminded us of the importance of testing this sensorineural function. We retrace here the main historical steps and discoveries concerning olfaction and anosmia.
Topics: Anosmia; COVID-19; Humans; Olfaction Disorders; Pandemics; SARS-CoV-2; Smell
PubMed: 33848701
DOI: 10.1016/j.jns.2021.117433 -
Molecular Neurobiology Feb 2021COVID-19 is a highly infectious viral disease caused by the novel coronavirus SARS-CoV-2. While it was initially regarded as a strictly respiratory illness, the impact... (Review)
Review
COVID-19 is a highly infectious viral disease caused by the novel coronavirus SARS-CoV-2. While it was initially regarded as a strictly respiratory illness, the impact of COVID-19 on multiple organs is increasingly recognized. The brain is among the targets of COVID-19, and it can be impacted in multiple ways, both directly and indirectly. Direct brain infection by SARS-CoV-2 may occur via axonal transport via the olfactory nerve, eventually infecting the olfactory cortex and other structures in the temporal lobe, and potentially the brain stem. A hematogenous route, which involves viral crossing of blood-brain barrier, is also possible. Secondary mechanisms involve hypoxia due to respiratory failure, as well as aberrant immune response leading to various forms of encephalopathy, white matter damage, and abnormal blood clotting resulting in stroke. Multiple neurological symptoms of COVID-19 have been described. These involve anosmia/ageusia, headaches, seizures, mental confusion and delirium, and coma. There is a growing concern that in a number of patients, long-term or perhaps even permanent cognitive impairment will persist well after the recovery from acute illness. Furthermore, COVID-19 survivors may be at increased risk for developing neurodegenerative diseases years or decades later. Since COVID-19 is a new disease, it will take months or even years to characterize the exact nature, scope, and temporal extent of its long-term neurocognitive sequelae. To that end, rigorous and systematic longitudinal follow-up will be required. For this effort to succeed, appropriate protocols and patient registries should be developed and put in place without delay now.
Topics: Anosmia; Blood-Brain Barrier; Brain; COVID-19; Coma; Delirium; Headache; Humans; Seizures
PubMed: 32990925
DOI: 10.1007/s12035-020-02152-5 -
Cureus Oct 2022With the evolving understanding of COVID-19, a thorough analysis of the effects of this unique coronavirus on the affected people's olfactory abilities could highlight... (Review)
Review
With the evolving understanding of COVID-19, a thorough analysis of the effects of this unique coronavirus on the affected people's olfactory abilities could highlight the disease's specific course of treatment. Researchers have discovered that the neurological side effects of SARS-CoV-2 infection include acute anosmia and ageusia. This work aims to review the relevant mechanisms, provide information on COVID-19-related anosmia, and suggest a novel approach to treating long-term anosmia brought on by coronavirus disease. For that, we did a thorough literature assessment of the subject from various online resources, including PubMed, Scopus, and Google Scholar. We evaluated the publications that described anosmia in COVID-19 and its management. In patients with SARS-CoV-2 infections, the angiotensin-converting enzyme two receptor plays a crucial role in the anosmia process. Olfactory systems are directly harmed by new coronaviruses when they connect with sustentacular cells' ACE-2 (Angiotensin converting enzyme-2) receptors. Other suggested processes include the virus's infiltration of the olfactory nerve and the ensuing local inflammation. Therefore, neuroprotective, anti-inflammatory, or depolarizing medications may be helpful for COVID-19 individuals who have lost their sense of smell. According to the available data, we found out olfactory training, topical or oral corticosteroids, caffeine, insulin, or minocycline may effectively treat COVID-19 odor loss. A novel method of treating long-term COVID-19 with persistent anosmia can be suggested based on recent investigations. The path to effective anosmia management is still somewhat hazy, but there is hope that we can find the right treatment plan with the right clinical trials and additional research. People who lost their sense of smell during COVID-19 can be reassured that recovery is typically possible.
PubMed: 36407192
DOI: 10.7759/cureus.30425 -
PloS One 2021Qualitative olfactory (smell) dysfunctions are a common side effect of post-viral illness and known to impact quality of life and health status. Evidence is emerging...
BACKGROUND
Qualitative olfactory (smell) dysfunctions are a common side effect of post-viral illness and known to impact quality of life and health status. Evidence is emerging that taste and smell loss are common symptoms of Covid-19 that may emerge and persist long after initial infection. The aim of the present study was to document the impact of post Covid-19 alterations to taste and smell.
METHODS
We conducted exploratory thematic analysis of user-generated text from 9000 users of the AbScent Covid-19 Smell and Taste Loss moderated Facebook support group from March 24 to 30th September 2020.
RESULTS
Participants reported difficulty explaining and managing an altered sense of taste and smell; a lack of interpersonal and professional explanation or support; altered eating; appetite loss, weight change; loss of pleasure in food, eating and social engagement; altered intimacy and an altered relationship to self and others.
CONCLUSIONS
Our findings suggest altered taste and smell with Covid-19 may lead to severe disruption to daily living that impacts on psychological well-being, physical health, relationships and sense of self. More specifically, participants reported impacts that related to reduced desire and ability to eat and prepare food; weight gain, weight loss and nutritional insufficiency; emotional wellbeing; professional practice; intimacy and social bonding; and the disruption of people's sense of reality and themselves. Our findings should inform further research and suggest areas for the training, assessment and treatment practices of health care professionals working with long Covid.
Topics: Adult; Anosmia; COVID-19; Female; Humans; Male; Middle Aged; Olfactory Perception; SARS-CoV-2; Taste Disorders; Taste Perception; Time Factors
PubMed: 34559820
DOI: 10.1371/journal.pone.0256998 -
American Journal of Rhinology & Allergy Nov 2021Anosmia and ageusia are symptoms commonly associated with COVID-19, but the relationship with disease severity, onset and recovery are unclear.
BACKGROUND
Anosmia and ageusia are symptoms commonly associated with COVID-19, but the relationship with disease severity, onset and recovery are unclear.
OBJECTIVE
To examine factors associated with anosmia and ageusia and the recovery from these symptoms in an ethnically diverse cohort.
METHODS
Individuals tested for SARS-CoV-2 between March and April 2020 were eligible for the study. Randomly selected participants answered a telephone questionnaire on COVID-19 symptoms with a focus on anosmia and ageusia. Additionally, relevant past medical history and data on the COVID-19 clinical course were obtained from electronic medical records. 486 patients were in the COVID-19 group and 103 were COVID-19-negative.
RESULTS
Patients who were younger were more likely to report anosmia and/or ageusia (odds ratio (OR) for anosmia per 1-year increase in age: 0·98, 95%CI:0-97-0·99, = 0·003; for ageusia: 0·98, 95%CI:0·97-0·99, = 0·005) as were patients with lower eosinophil counts (OR for anosmia per 0.1-K/μL increase in eosinophils: 0·02, 95%CI:0·001-0·46, = 0·01, for ageusia 0·10, 95%CI:0·01-0·97, = 0·047). Male gender was independently associated with a lower probability of ageusia (OR:0·56, 95%CI:0·38-0·82, = 0·003) and earlier sense of taste recovery (HR:1·44, 95%CI:1·05-1·98, = 0·02). Latinos showed earlier sense of taste recovery than white patients (HR:1·82, 95%CI:1·05-3·18, = 0·03).
CONCLUSION
Anosmia and ageusia were more common among younger patients and those with lower blood eosinophil counts. Ageusia was less commonly reported among men, and time to taste recovery was earlier among both men and Latinos.
Topics: Ageusia; Anosmia; COVID-19; Eosinophils; Humans; Infant; Male; Olfaction Disorders; SARS-CoV-2
PubMed: 33813917
DOI: 10.1177/19458924211004800 -
MMW Fortschritte Der Medizin May 2022
Topics: Anosmia; COVID-19; Dermatologic Agents; Glucocorticoids; Humans; Olfaction Disorders; Smell
PubMed: 35513640
DOI: 10.1007/s15006-022-1124-4