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F1000Research 2021: The present study aimed to determine the global prevalence of anosmia and dysgeusia in coronavirus disease 2019 (COVID-19) patients and to assess their association... (Meta-Analysis)
Meta-Analysis
Anosmia and dysgeusia in SARS-CoV-2 infection: incidence and effects on COVID-19 severity and mortality, and the possible pathobiology mechanisms - a systematic review and meta-analysis.
: The present study aimed to determine the global prevalence of anosmia and dysgeusia in coronavirus disease 2019 (COVID-19) patients and to assess their association with severity and mortality of COVID-19. Moreover, this study aimed to discuss the possible pathobiological mechanisms of anosmia and dysgeusia in COVID-19. : Available articles from PubMed, Scopus, Web of Science, and preprint databases (MedRxiv, BioRxiv, and Researchsquare) were searched on November 10th, 2020. Data on the characteristics of the study (anosmia, dysgeusia, and COVID-19) were extracted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Newcastle-Ottawa scale was used to assess research quality. Moreover, the pooled prevalence of anosmia and dysgeusia were calculated, and the association between anosmia and dysgeusia in presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was assessed using the Z test. : Out of 32,142 COVID-19 patients from 107 studies, anosmia was reported in 12,038 patients with a prevalence of 38.2% (95% CI: 36.5%, 47.2%); whereas, dysgeusia was reported in 11,337 patients out of 30,901 COVID-19 patients from 101 studies, with prevalence of 36.6% (95% CI: 35.2%, 45.2%), worldwide. Furthermore, the prevalence of anosmia was 10.2-fold higher (OR: 10.21; 95% CI: 6.53, 15.96, < 0.001) and that of dysgeusia was 8.6-fold higher (OR: 8.61; 95% CI: 5.26, 14.11, < 0.001) in COVID-19 patients compared to those with other respiratory infections or COVID-19 like illness. To date, no study has assessed the association of anosmia and dysgeusia with severity and mortality of COVID-19. : Anosmia and dysgeusia are prevalent in COVID-19 patients compared to those with the other non-COVID-19 respiratory infections. Several possible mechanisms have been hypothesized; however, future studies are warranted to elucidate the definitive mechanisms of anosmia and dysgeusia in COVID-19. PROSPERO CRD42020223204.
Topics: Anosmia; COVID-19; Dysgeusia; Humans; Incidence
PubMed: 33824716
DOI: 10.12688/f1000research.28393.1 -
Cells Feb 2022Among the first clinical symptoms of the SARS-CoV-2 infection is olfactory−gustatory deficit; this continues for weeks and, in some cases, can be persistent. We...
Among the first clinical symptoms of the SARS-CoV-2 infection is olfactory−gustatory deficit; this continues for weeks and, in some cases, can be persistent. We prospectively evaluated 162 patients affected by COVID-19 using a visual analogue scale (VAS) for nasal and olfactory−gustatory symptoms. Patients were checked after 7, 14, 21, 28, 90, and 180 days. A total of 118 patients (72.8%) reported an olfactory VAS < 7 at baseline (group B), and 44 (27.2%) reported anosmia (VAS ≥ 7) (group A) and underwent the Brief Smell Identification Test (B-SIT) and Burghart Taste Strips (BTS) to quantify the deficit objectively and repeated the tests to confirm the sense recovery. Group A patients showed B-SIT anosmia and hyposmia in 44.2% and 55.8% of cases, respectively. A total of 88.6% of group A patients reported ageusia with VAS ≥ 7, and BTS confirmed 81.8% of ageusia and 18.2% of hypogeusia. VAS smell recovery was recorded starting from 14 days, with normalization at 28 days. The 28-day B-SIT score showed normosmia in 90.6% of group A patients. The mean time for full recovery (VAS = 0) was shorter in group B (22.9 days) than in group A (31.9 days). Chemosensory deficit is frequently the first symptom in patients with COVID-19, and, in most cases, recovery occurs after four weeks.
Topics: Ageusia; Anosmia; COVID-19; Humans; Olfaction Disorders; SARS-CoV-2; Smell; Taste
PubMed: 35269410
DOI: 10.3390/cells11050788 -
American Journal of Rhinology & Allergy Jan 2023Nearly 40% of patients who experience smell loss during SARS-CoV-2 infection may develop qualitative olfactory dysfunction, most commonly parosmia. Our evidence-based... (Review)
Review
BACKGROUND
Nearly 40% of patients who experience smell loss during SARS-CoV-2 infection may develop qualitative olfactory dysfunction, most commonly parosmia. Our evidence-based review summarizes the evolving literature and offers recommendations for the clinician on the management of patients experiencing parosmia associated with COVID-19.
METHODS
We performed a systematic search using independent queries in PubMed, Embase, Ovid, and Cochrane databases, then categorized articles according to themes that emerged regarding epidemiology, effect on quality of life, disease progression, prognosis, pathophysiology, diagnosis, and treatment of parosmia.
RESULTS
We identified 123 unique references meeting eligibility and performed title and abstract review with 2 independent reviewers, with 74 articles undergoing full-text review. An inductive approach to thematic development provided 7 central themes regarding qualitative olfactory dysfunction following COVID-19.
CONCLUSIONS
While other respiratory viruses are known to cause qualitative olfactory disturbances, the incidence of parosmia following COVID-19 is notable, and correlates negatively with age. The presence of parosmia predicts persistent quantitative olfactory dysfunction. Onset can occur months after infection, and symptoms may persist for well over 7 months. Affected patients report increased anxiety and decreased quality of life. Structured olfactory training with essential oils is the preferred treatment, where parosmia predicts recovery of aspects of quantitative smell loss when undergoing training. There is limited evidence that nasal corticosteroids may accelerate recovery of olfactory function. Patients should be prepared for the possibility that symptoms may persist for years, and providers should guide them to resources for coping with their psychosocial burden.
Topics: Humans; Anosmia; COVID-19; Olfaction Disorders; Quality of Life; SARS-CoV-2; Smell
PubMed: 35957578
DOI: 10.1177/19458924221120117 -
JCI Insight Dec 2022Loss of olfactory function has been commonly reported in SARS-CoV-2 infections. Recovery from anosmia is not well understood. Previous studies showed that sustentacular...
Loss of olfactory function has been commonly reported in SARS-CoV-2 infections. Recovery from anosmia is not well understood. Previous studies showed that sustentacular cells, and occasionally olfactory sensory neurons (OSNs) in the olfactory epithelium (OE), are infected in SARS-CoV-2-infected patients and experimental animals. Here, we show that SARS-CoV-2 infection of sustentacular cells induces inflammation characterized by infiltration of myeloid cells to the olfactory epithelium and variably increased expression of proinflammatory cytokines. We observed widespread damage to, and loss of cilia on, OSNs, accompanied by downregulation of olfactory receptors and signal transduction molecules involved in olfaction. A consequence of OSN dysfunction was a reduction in the number of neurons in the olfactory bulb expressing tyrosine hydroxylase, consistent with reduced synaptic input. Resolution of the infection, inflammation, and olfactory dysfunction occurred over 3-4 weeks following infection in most but not all animals. We also observed similar patterns of OE infection and anosmia/hyposmia in mice infected with other human coronaviruses such as SARS-CoV and MERS-CoV. Together, these results define the downstream effects of sustentacular cell infection and provide insight into olfactory dysfunction in COVID-19-associated anosmia.
Topics: Humans; Animals; Mice; COVID-19; Smell; SARS-CoV-2; Anosmia; Olfaction Disorders; Inflammation; Signal Transduction
PubMed: 36378534
DOI: 10.1172/jci.insight.160277 -
Viruses Nov 2021Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of coronavirus disease 2019 (COVID-19). It is known as a respiratory virus, but... (Review)
Review
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of coronavirus disease 2019 (COVID-19). It is known as a respiratory virus, but SARS-CoV-2 appears equally, or even more, infectious for the olfactory epithelium (OE) than for the respiratory epithelium in the nasal cavity. In light of the small area of the OE relative to the respiratory epithelium, the high prevalence of olfactory dysfunctions (ODs) in COVID-19 has been bewildering and has attracted much attention. This review aims to first examine the cytological and molecular biological characteristics of the OE, especially the microvillous apical surfaces of sustentacular cells and the abundant SARS-CoV-2 receptor molecules thereof, that may underlie the high susceptibility of this neuroepithelium to SARS-CoV-2 infection and damages. The possibility of SARS-CoV-2 neurotropism, or the lack of it, is then analyzed with regard to the expression of the receptor (angiotensin-converting enzyme 2) or priming protease (transmembrane serine protease 2), and cellular targets of infection. Neuropathology of COVID-19 in the OE, olfactory bulb, and other related neural structures are also reviewed. Toward the end, we present our perspectives regarding possible mechanisms of SARS-CoV-2 neuropathogenesis and ODs, in the absence of substantial viral infection of neurons. Plausible causes for persistent ODs in some COVID-19 convalescents are also examined.
Topics: Angiotensin-Converting Enzyme 2; Anosmia; COVID-19; Humans; Olfactory Bulb; Olfactory Mucosa; Prevalence; Receptors, Coronavirus; SARS-CoV-2; Viral Tropism
PubMed: 34835030
DOI: 10.3390/v13112225 -
Brazilian Journal of Otorhinolaryngology 2021
Topics: Anosmia; COVID-19; Humans; Olfaction Disorders; SARS-CoV-2
PubMed: 33992555
DOI: 10.1016/j.bjorl.2021.04.007 -
Saudi Medical Journal Dec 2022To investigate the impact of olfactory dysfunction's (OD) on patients with coronavirus disease-19 (COVID-19) and evaluate the risk factors associated with it.
OBJECTIVES
To investigate the impact of olfactory dysfunction's (OD) on patients with coronavirus disease-19 (COVID-19) and evaluate the risk factors associated with it.
METHODS
This cross-sectional study analyzed patients who tested positive for COVID-19 over a period of 4 months (May-July 2020) and experienced OD and mild illness. Selected patients were given 2 scales Olfactory Disorders Negative Statement (QOD-NS) and Sino-nasal Outcome Test (SNOT-22).
RESULTS
A total of 256 patients were enrolled, out of which 196 had anosmia after COVID-19 infection. More than 75% of the participants were aged between 20-40 years and 64.3% were women. The mean score of the patients was 25.13 (SD 19.6) on the SNOT-22, while it was 4.9 (SD 4.85) on the QOD-NS. There was no association between anosmia and other comorbidities and factors (age, smoking history, allergic rhinitis history, asthma, and so on). Only 39% of patients who had anosmia after COVID-19 recovered in less than 4 months.
CONCLUSION
Olfactory dysfunction is a common symptom of COVID-19 infection and it can take more than 4 months to recover. Nevertheless, this cohort reports a moderate impact on their quality of life due to anosmia.
Topics: Humans; Female; Young Adult; Adult; Male; Anosmia; COVID-19; Cross-Sectional Studies; SARS-CoV-2; Quality of Life; Incidence; Saudi Arabia; Olfaction Disorders
PubMed: 36517057
DOI: 10.15537/smj.2022.43.12.20220559 -
International Archives of... Jan 2021The number of positive cases and deaths from the coronavirus disease 2019 (COVID-19) is still increasing. The early detection of the disease is very important.... (Review)
Review
The number of positive cases and deaths from the coronavirus disease 2019 (COVID-19) is still increasing. The early detection of the disease is very important. Olfactory dysfunction has been reported as the main symptom in part of the patients. To analyze the potential usefulness of anosmia or hyposmia in the detection of the COVID-19 infection. We systematically searched the PubMed Central database using specific keywords related to our aims until July 31st, 2020. All articles published on COVID-19 and anosmia or hyposmia were retrieved. A statistical analysis was performed using the Review Manager (RevMan, Cochrane, London, UK) software, version 5.4. A total of 10 studies involving 21,638 patients were included in the present analysis. The meta-analysis showed that anosmia or hyposmia is significantly associated with positive COVID-19 infections (risk ratio [RR]: 4.56; 95% confidence interval [95%CI]: 3.32-6.24; < 0.00001; I = 78%, random-effects modeling). The presence of anosmia or hyposmia is a good predictor of positive COVID-19 infections. Patients with onset of anosmia or hyposmia should take the test or undergo screening for the possibility of COVID-19 infection.
PubMed: 33552295
DOI: 10.1055/s-0040-1719120 -
International Journal of Infectious... Jun 2021The cutaneous manifestations of coronavirus disease 2019 (COVID-19) have been covered insufficiently in the literature. (Review)
Review
BACKGROUND
The cutaneous manifestations of coronavirus disease 2019 (COVID-19) have been covered insufficiently in the literature.
METHODS
Thirty-nine patients admitted to the study hospital with confirmed COVID-19 who experienced various skin manifestations during hospitalization or in the convalescence period, were analysed retrospectively.
RESULTS
Thirty-nine patients with COVID-19, admitted to the study hospital between 23 March and 12 September 2020, had intra-infectious rash or lesions of cutaneous vasculitis during convalescence. The most common cutaneous manifestations of COVID-19 were erythematous and erythematous papular rash. Twenty-seven of the 39 patients had anosmia (69.2%), 26 patients had ageusia (66.7%), 34 patients had pneumonia (87.2%) and 24 patients had intra-infectious enterocolitis (61.5%). Skin biopsies were rarely performed in these patients. This article reports the results of biopsies performed in two patients, showing histopathological and immunohistochemical changes in erythematous rash and erythema multiforme-like lesions. Both skin biopsies revealed early fibrous remodelling of the dermis, suggesting similarity with changes that occur in the lungs and other tissues in patients with COVID-19.
CONCLUSIONS
Correlations between skin lesions and anosmia, ageusia and enteritis in patients with COVID-19 do not seem to be accidental, but are associated with a similar response to ACE2 receptor expression in these tissues.
Topics: Ageusia; Anosmia; COVID-19; Enteritis; Female; Humans; Male; Retrospective Studies; SARS-CoV-2; Skin Diseases
PubMed: 33887455
DOI: 10.1016/j.ijid.2021.04.058 -
Journal of the Neurological Sciences Dec 2020Anosmia is common in Coronavirus disease 2019, but its impact on prognosis is unknown. We analysed whether anosmia predicts in-hospital mortality; and if patients with... (Observational Study)
Observational Study
BACKGROUND
Anosmia is common in Coronavirus disease 2019, but its impact on prognosis is unknown. We analysed whether anosmia predicts in-hospital mortality; and if patients with anosmia have a different clinical presentation, inflammatory response, or disease severity.
METHODS
Retrospective cohort study including all consecutive hospitalized patients with confirmed Covid-19 from March 8th to April 11th, 2020. We determined all-cause mortality and need of intensive care unit (ICU) admission. We registered the first and worst laboratory parameters. Statistical analysis was done by multivariate logistic and linear regression.
RESULTS
We included 576 patients, 43.3% female, and aged 67.2 years in mean. Anosmia was present in 146 (25.3%) patients. Patients with anosmia were more frequently females, younger and less disabled and had less frequently hypertension, diabetes, smoking habit, cardiac and neurological comorbidities. Anosmia was independently associated with lower mortality (OR: 0.180, 95% CI: 0.069-0.472) and ICU admission (OR: 0.438, 95% CI: 0.229-0.838, p = 0.013). In the multivariate analysis, patients with anosmia had a higher frequency of cough (OR: 1.96, 95%CI: 1.18-3.28), headache (OR: 2.58, 95% CI: 1.66-4.03), and myalgia (OR: 1.74, 95% CI: 1.12-2.71). They had higher adjusted values of hemoglobin (+0.87, 95% CI: 0.40-1.34), lymphocytes (+849.24, 95% CI: 157.45-1541.04), glomerular filtration rate (+6.42, 95% CI: 2.14-10.71), and lower D-dimer (-4886.52, 95% CI: -8655.29-(-1117.75)), and C-reactive protein (-24.92, 95% CI: -47.35-(-2.48)).
CONCLUSIONS
Hospitalized Covid-19 patients with anosmia had a lower adjusted mortality rate and less severe course of the disease. This could be related to a distinct clinical presentation and a different inflammatory response.
Topics: Aged; Anosmia; COVID-19; COVID-19 Testing; Comorbidity; Female; Hospital Mortality; Hospitalization; Humans; Intensive Care Units; Male; Middle Aged; Regression Analysis; Retrospective Studies; COVID-19 Drug Treatment
PubMed: 33035870
DOI: 10.1016/j.jns.2020.117163