Symptomatology of COVID-19 from the otorhinolaryngology perspective: a survey of 223 SARS-CoV-2 RNA-positive patients

The Correlation between the Results of the Sniffin' Sticks Test, Demographic Data, and Questionnaire of Olfactory Disorders in a Hungarian Population after a SARS-CoV-2 Infection

BACKGROUND

After a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, smell disorders frequently occur, significantly affecting patients' quality of life (QoL).

METHODS

110 patients with persistent olfactory disorder after coronavirus infection were enrolled. These patients underwent chemosensory testing using the Sniffin' Sticks test, and completed the Questionnaire of Olfactory Disorders (QOD).

RESULTS

30% of the patients reported anosmia, and 70% reported hyposmia. Upon comparing subjective and chemosensory testing categories, good category matching was observed in 75.3% (i.e., anosmia based on both methods in 10 and hyposmia in 48 cases). Statistical analysis using the Chi-square test revealed a significant result (p = 0.001 *). Between the TDI (i.e., Threshold, Discrimination, Identification) results of the three subjective report groups (i.e., hyposmia, anosmia, and parosmia), no significant differences were observed. When the TDI and QOD results were compared, no consistent significant correlations were found in most TDI and QOD outcomes. Between the TDI and Scale 2 results, a significant, although slight correlation was observed by the Spearman's (rho = 0.213, p = 0.027 *) and Pearson's (rho = 0.201, p = 0.037 *) tests.

CONCLUSIONS

The nonsignificant correlation between objective and subjective methods suggests that these results should be interpreted independently. Moreover, adequate management is essential even in mild cases.

Prevalence and Factors of Postpartum Depression During the COVID-19 Pandemic: A Review

The COVID-19 (Coronavirus Disease 2019) pandemic has led to several mandatory prevention regulations, changes in healthcare services, unprecedented unemployment rates, financial stress, and emotional worries. Given the increasing cases of COVID-19, coupled with the drastic physical and psychological changes within postpartum mothers during the postpartum period, this paper aims to present an overview of the postpartum depression (PPD) among postpartum women during the COVID-19 pandemic. The postpartum period is characterized by drastic physical changes and substantial demands on parental role adjustment, and it places enormous stress on the mothers and makes them vulnerable to mental health problems. A literature search was conducted in four electronic databases (ScienceDirect, Scopus, Wiley, and SAGE) with different combinations of keywords were used. As the result, 25 articles that involved 10,515 postpartum women from 14 countries were extracted. Results have recorded PPD prevalence ranged from 6.4% to 56.9% during the COVID-19 pandemic. Limited social support, social isolation, fear of COVID-19 exposure, or infection for themselves, newborns, have worsening PPD symptoms among postpartum women. In brief, early detection, appropriate and timely intervention is needed to prevent and identify PPD among postpartum women during the COVID-19 pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12144-022-04181-w.

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.

Detection and classification of lung diseases for pneumonia and Covid-19 using machine and deep learning techniques

Since the arrival of the novel Covid-19, several types of researches have been initiated for its accurate prediction across the world. The earlier lung disease pneumonia is closely related to Covid-19, as several patients died due to high chest congestion (pneumonic condition). It is challenging to differentiate Covid-19 and pneumonia lung diseases for medical experts. The chest X-ray imaging is the most reliable method for lung disease prediction. In this paper, we propose a novel framework for the lung disease predictions like pneumonia and Covid-19 from the chest X-ray images of patients. The framework consists of dataset acquisition, image quality enhancement, adaptive and accurate region of interest (ROI) estimation, features extraction, and disease anticipation. In dataset acquisition, we have used two publically available chest X-ray image datasets. As the image quality degraded while taking X-ray, we have applied the image quality enhancement using median filtering followed by histogram equalization. For accurate ROI extraction of chest regions, we have designed a modified region growing technique that consists of dynamic region selection based on pixel intensity values and morphological operations. For accurate detection of diseases, robust set of features plays a vital role. We have extracted visual, shape, texture, and intensity features from each ROI image followed by normalization. For normalization, we formulated a robust technique to enhance the detection and classification results. Soft computing methods such as artificial neural network (ANN), support vector machine (SVM), K-nearest neighbour (KNN), ensemble classifier, and deep learning classifier are used for classification. For accurate detection of lung disease, deep learning architecture has been proposed using recurrent neural network (RNN) with long short-term memory (LSTM). Experimental results show the robustness and efficiency of the proposed model in comparison to the existing state-of-the-art methods.

What Is the Long-Term Findings of Olfactory and Taste Loss due to COVID-19?

Objectives

The objective of this study was to determine prevalance, severity, course, and long-term findings of smell and taste disorders of coronavirus disease 2019 (COVID-19) patients in mild-moderate and severe-critical disease spectrum.

Methods

All adult patients conducted in our hospital with positive severe acute respiratory syndrome coronavirus 2 between March and April 2020 were surveyed during disease course and those with olfactory and taste loss were re-surveyed to determine the course and progress of these symptoms after at least 12-month follow-up. Demographic features and clinical findings were evaluated as well as disease severity.

Results

A total of 77 patients with smell and/or taste loss symptoms were included in the study. At diagnosis, 58 (75.3%) patients had loss of smell and 75 (97.4%) had loss of taste. After a follow-up period of 12-14 months, 12 (15.6%) patients had ongoing loss of smell and six (8%) patients had ongoing loss of taste. Three (3.9%) patients complained of cacosmia and 5 (6.5%) complained of parosmia at follow-up. The presence of ongoing visual analog scale scores of smell and/or taste was not statistically significant between male and female patients. When presence and severity of symptoms were compared by disease severity, no statistically significant difference was found.

Conclusion

Smell and taste loss seem to be among the presenting symptoms of COVID-19. The prognosis and the treatment of the smell loss and taste loss in COVID-19 patients remains unclear. To improve and accelerate recovery, the pathophysiology and the treatment options must be validated.

Is COVID-19 to Blame for Sensorineural Hearing Deterioration? A Pre/Post COVID-19 Hearing Evaluation Study

OBJECTIVES

Here, we aimed to (a) determine whether a clinically significant sensorineural hearing loss (SNHL) change could be detected in post-coronavirus disease (COVID-19) hearing levels on comparing them with pre-infection hearing levels after controlling for the effect of age and (b) to identify risk factors, such as hypertension, diabetes, and smoking, which increase the likelihood of hearing loss in COVID-19 patients.

METHODS

We retrospectively analyzed hearing thresholds in unvaccinated patient's pre- and post-COVID-19 infection. Thresholds were controlled for age and the duration between the pre- and post-COVID-19 hearing evaluations. Correlations between additional COVID-19-related symptoms, hypertension, diabetes, and smoking and hearing threshold changes were analyzed.

RESULTS

A significant (but not clinical) threshold elevation was found post-COVID-19 infection. However, on controlling for age and the duration between the pre- and post-COVID-19 hearing evaluations, no significant threshold elevation was found. No significant correlation was found between hearing threshold changes and additional COVID-19-related symptoms, hypertension, diabetes, or smoking.

CONCLUSION

COVID-19 did not lead to a significant hearing threshold elevation in our cohort, even among patients with additional COVID-19 symptoms, hypertension, or diabetes mellitus or among those who smoked.

LEVEL OF EVIDENCE: 3

nonrandomized controlled cohort, follow-up study Laryngoscope, 2022.

Changing Trends in COVID-19 Symptomatology: A Survey-Based Analysis

India currently ranks the highest in the world with over 3.86 lakhs new COVID-19 cases per day. With a spike in the number of cases in the second wave of COVID-19 in 2021 compared to the first wave of the outbreak in 2020, there have been varied clinical manifestations among masses. This study aimed to determine the changing trends in prevalence of COVID-19 symptoms during the pandemic. A cross-sectional study among 166 individuals was carried out using a self-designed survey-based questionnaire. Two groups were made on the basis of symptoms and compared: Group A- patients who tested COVID-19 positive in 2020 and Group B- patients who tested COVID-19 positive in 2021. 130 participants (78.31%) had tested positive for COVID-19, out of which 110 (84.62%) were symptomatic and 20 (15.38%) were asymptomatic. Fever was the most common presenting symptom (27.69%) followed by difficulty in breathing (24.62%). Group A individuals (n = 37), reported fever as the most common presenting symptom (45.95%), followed by body ache (13.51%); while those in Group B (n = 93) reported difficulty in breathing (33.33%) followed by fever (20.43%). The most common general symptoms were fever and difficulty in breathing while sore throat, cough and anosmia were the most common ENT symptoms. 57.83% had been vaccinated out of which 38.55% experienced symptoms post-vaccination. The prevalence of symptoms in the first and second wave of the pandemic can help in better understanding of the changing symptomatology of SARS-CoV-2 virus.

Olfactory dysfunction in COVID-19, new insights from a cohort of 353 patients: The ANOSVID study

Olfactory disorders (OD) pathogenesis, underlying conditions, and prognostic in coronavirus disease 2019 (COVID-19) remain partially described. ANOSVID is a retrospective study in Nord Franche-Comté Hospital (France) that included COVID-19 patients from March 1 2020 to May 31 2020. The aim was to compare COVID-19 patients with OD (OD group) and patients without OD (no-OD group). A second analysis compared patients with anosmia (high OD group) and patients with hyposmia or no OD (low or no-OD group). The OD group presented less cardiovascular and other respiratory diseases compared to the no-OD group (odds ratio [OR] = 0.536 [0.293-0.981], p = 0.041 and OR = 0.222 [0.056-0.874], p = 0.037 respectively). Moreover, history of malignancy was less present in the high OD group compared with the low or no-OD group (OR = 0.170 [0.064-0.455], p < 0.001). The main associated symptoms (OR > 5) with OD were loss of taste (OR = 24.059 [13.474-42.959], p = 0.000) and cacosmia (OR = 5.821 [2.246-15.085], p < 0.001). Most of all ORs decreased in the second analysis, especially for general, digestive, and ENT symptoms. Only two ORs increased: headache (OR = 2.697 [1.746-4.167], p < 0.001) and facial pain (OR = 2.901 [1.441-5.842], p = 0.002). The high OD group had a higher creatinine clearance CKD than the low or no-OD group (89.0 ± 21.1 vs. 81.0 ± 20.5, p = 0.040). No significant difference was found concerning the virological, radiological, and severity criteria. OD patients seem to have less comorbidity, especially better cardiovascular and renal function. Associated symptoms with OD were mostly neurological symptoms. We did not find a significant relationship between OD and less severity in COVID-19 possibly due to methodological bias.

Oral Manifestations of COVID-19: A Cross-Sectional Study of Their Prevalence and Association with Disease Severity

Background: COVID-19, caused by SARS-CoV-2, has impacted the world in an unprecedented way since December 2019. SARS-CoV-2 was found in the saliva of patients, and entry points for the virus may have been through the numerous angiotensin-converting enzyme 2 receptors in the oral cavity. Oral manifestations of COVID-19 could contribute to the burden of oral disease. Objective: To determine the prevalence of oral manifestations of COVID-19 in patients and their association with disease severity. Methods: Interviews were conducted with adult participants diagnosed with COVID-19 between October 2021 and March 2022 to document their demographic and health status data, symptoms, and the presence of oral manifestations of COVID-19. Chi-square and the Fisher’s exact test were used to compare data on the presence or absence of oral manifestations of COVID-19. Results: Of 195 participants interviewed, 33% were 18 to 24 years old, 33% were 25 to 34 years old, and 75% were female. A total of 57 (29%) had oral manifestations; the most common were taste disorders (60%), xerostomia (42%), and oral ulcers (11%). There was no relationship between the severity of COVID-19 and the presence of the oral manifestations. Conclusion: Oral manifestations of COVID-19 were common among female patients and linked to certain general COVID-19 symptoms regarding frequency and extent.

Correlation of SARS-CoV-2 infection severity with ABO blood groups and RhD antigen: a case-control study

Objective

The role of ABO types and RhD antigen in coronavirus disease 2019 (COVID-19) severity has been investigated in several recent studies. Thus, the objective of this study was to identify the relationship of ABO and RhD types with symptomatic COVID-19 disease and determine the groups associated with an increased risk of hospitalization.

Methods

This observational case-control study was performed in 530 Iraqi-Kurdish patients with COVID-19. Among them, 184 were severe cases that required hospitalization, while 346 were mild to moderate cases that were treated at home. ABO and RhD antigen groups were compared between cases and 1698 control records from 1 year before the pandemic. The diagnosis of COVID-19 was based on real-time polymerase chain reaction tests and high-resolution chest computed tomography scans with the typical clinical presentation.

Results

There were no significant differences in ABO and RhD antigen distributions between the COVID-19 cases and non-COVID controls. No ABO group was associated with the risk of hospitalization as a marker of the severity of infection.

Conclusions

There was no significant association between symptomatic COVID-19 disease and any ABO group or RhD antigen type. No impact of ABO groups on hospitalization was documented.

The Prevalence and Pathophysiology of Chemical Sense Disorder Caused by the Novel Coronavirus

Emerging viral infections are a ceaseless challenge and remain a global public health concern. The world has not yet come back to normal from the devastating effects of the highly contagious and pathogenic novel coronavirus, or Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Olfactory and taste dysfunction is common in patients infected by the novel coronavirus. In light of the emergence of different coronavirus variants, it is important to update the prevalence and pathophysiology of these side effects. In this review, articles published on the prevalence of olfactory and taste dysfunction from coronavirus disease (COVID-19) and their possible pathophysiologic mechanisms have been reviewed and reported. The modulatory role of different SARS-CoV-2 variants on the chemical senses is then described. The clinical relevance of chemical sense disorder and its long-term morbidity and management is also discussed.

Testing for anosmia and ageusia in patients presenting to the emergency department with suspected coronavirus disease 2019 in Saudi Arabia

Objective

This study investigated the role of objective olfactory dysfunction (OD) and gustatory dysfunction (GD) testing among patients with suspected coronavirus disease 2019 (COVID-19) who presented with respiratory symptoms.

Methods

A prospective, blinded, observational study was conducted in the emergency units of two tertiary hospitals. Participants were asked to identify scents in the pocket smell test (PST) and flavors in four different solutions in the gustatory dysfunction test (GDT). We assessed the level of agreement between objective findings and self-reported symptoms. We evaluated the diagnostic accuracy of chemosensory dysfunction for diagnosing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Results

Of 250 participants, 74 (29.6%) were SARS-CoV-2-positive. There was slight agreement between self-reported symptoms and objective findings (kappa = 0.13 and 0.10 for OD and GD, respectively). OD assessed by the PST was independently associated with COVID-19 (adjusted odds ratio = 1.89, 95% confidence interval, 1.04–3.46). This association was stronger when OD was combined with objective GD, cough, and fever (adjusted odds ratio = 7.33, 95% confidence interval, 1.17–45.84).

Conclusions

Neither the PST nor GDT alone are useful screening tools for COVID-19. However, a diagnostic scale based on objective OD, GD, fever, and cough may help triage patients with suspected COVID-19.

Otologic and vestibular symptoms in COVID-19: A scoping review

Background

Otologic and vestibular symptoms have been seen in patients confirmed to have COVID-19 disease. Further discussion of these symptoms may provide insight into short- and long-term management for these patients.

Objective

The aim of this review was to describe the otologic and vestibular symptoms that present in patients with COVID-19. The primary outcomes of this review were onset, duration and clinical outcomes of these symptoms.

Sources of Evidence

Pub Med, APAMed Central, Herdin, CINAHL, Scopus, Springer Link, ProQuest Coronavirus Research Database, and Google Scholar were searched for the articles to be included.

Eligibility Criteria

Studies included were those involving adult patients diagnosed with COVID-19 who experienced hearing loss, ear pain, ear discharge, otitis media, vertigo, or tinnitus. Studies were eligible for inclusion if there was a description of the otologic dysfunction, specifically onset, duration, or clinical outcomes.

Results

The majority of patients who experienced hearing loss (68%), tinnitus (88%), vertigo/dizziness (30%), ear pain (8%), and discharge (100%) did so within a month of experiencing the typical symptoms of COVID-19. A majority also experienced complete resolution of their symptoms within 2 weeks. Standard treatment for COVID-19 was usually provided but when specific diagnoses are made for these symptoms (e.g., sudden sensorineural hearing loss, otitis media, vestibular neuritis), they are treated in the same manner as one would for non-COVID-19 cases, in addition to the management for COVID-19. In certain cases, there may be a need for additional work-up to rule out other causes.

Conclusions

Otologic and vestibular symptoms were present in COVID-19 patients, majority as part of the systemic nature of the disease. The onset, duration, and course were consistent with the natural history of a systemic viral infection. COVID-19 should be considered in any patient with a new-onset hearing loss, tinnitus, or vertigo/dizziness, even in the absence of infectious or respiratory symptoms.

Gustatory and Saliva Secretory Dysfunctions in COVID-19 Patients with Zinc Deficiency

Given the ever-progressing studies on coronavirus disease 2019 (COVID-19), it is critical to update our knowledge about COVID-19 symptomatology and pathophysiology. In the present narrative review, oral symptoms were overviewed using the latest data and their pathogenesis was hypothetically speculated. PubMed, LitCovid, ProQuest, and Google Scholar were searched for relevant studies from 1 April 2021 with a cutoff date of 31 January 2022. The literature search indicated that gustatory dysfunction and saliva secretory dysfunction are prevalent in COVID-19 patients and both dysfunctions persist after recovery from the disease, suggesting the pathogenic mechanism common to these cooccurring symptoms. COVID-19 patients are characterized by hypozincemia, in which zinc is possibly redistributed from blood to the liver at the expense of zinc in other tissues. If COVID-19 induces intracellular zinc deficiency, the activity of zinc-metalloenzyme carbonic anhydrase localized in taste buds and salivary glands may be influenced to adversely affect gustatory and saliva secretory functions. Zinc-binding metallothioneins and zinc transporters, which cooperatively control cellular zinc homeostasis, are expressed in oral tissues participating in taste and saliva secretion. Their expression dysregulation associated with COVID-19-induced zinc deficiency may have some effect on oral functions. Zinc supplementation is expected to improve oral symptoms in COVID-19 patients.

Acute Vertigo After COVID-19 Vaccination: Case Series and Literature Review

Objective: The aim of this study was to present some cases of acute vertigo potentially related to the coronavirus disease 2019 (COVID-19) vaccine and review the available literature about cochleovestibular dysfunction after the COVID-19 vaccination.

Methods: In the period from May to July 2021, we evaluated 33 patients (mean age 54.3 ± 14.1) with “acute vertigo” post COVID-19 vaccination. A detailed medical history was taken on comorbidities, types of vaccines received, and symptoms associated. All patients underwent otoneurological evaluation, such as head impulse test, nystagmus evaluation, test of skew (HINTS) examination. Head shaking test-induced nystagmus, hyperventilation-induced nystagmus, and parossistic positional nystagmus were studied to search for vestibular impairment.

Results: Symptoms included 16 patients (48.5%) with objective vertigo, 14 patients (42.4%) with subjective vertigo, and 3 patients (9.1%) with dizziness. Of the associated ear, nose, and throat (ENT) symptoms, the most expressed was tinnitus (18.2%). Bedside examination showed absent nystagmus in 7 patients (21.2%), 9 patients (27.3%) had horizontal or rotatory nystagmus, 17 patients (51.5%) had a vertical or oblique nystagmus, negative HST, or “central HINTS.”

Discussion and Conclusions: The 9 patients had an evoked nystagmus pathognomonic for benign paroxysmal positional vertigo; in the remaining 17 cases, peripheral vestibular dysfunction could be excluded and central disorder may be suggested. Due to the prevalence of nystagmus of non-peripheral origin, a central nervous system involvement could not be excluded. However, due to the small sample size, a definite cause–effect relationship between vaccination and vertigo cannot be inferred. In light of expected third dose, large-scale and well-designed studies are needed to better define possible adverse reactions of the COVID-19 vaccine.

Efficacy of the use of mefenamic acid combined with standard medical care vs. standard medical care alone for the treatment of COVID‑19: A randomized double‑blind placebo‑controlled trial

Mefenamic acid is a non‑steroidal anti‑inflammatory drug exhibiting a wide range of anti‑inflammatory, antipyretic, analgesic and probable antiviral activities. The present study evaluated the efficacy of treatment with mefenamic acid combined with standard medical care vs. standard medical care plus a placebo in ambulatory patients with coronavirus disease 2019 (COVID‑19; nasal/oropharyngeal swabs reverse transcription‑PCR test results positive for severe acute respiratory syndrome coronavirus 2). The present study is a phase II prospective, two‑arm, parallel‑group, randomized, double‑blind placebo‑controlled clinical trial which analyzed 36 patients. Two aspects were evaluated during the 14‑day follow‑up period: i) The time for reaching a patient acceptable symptom state (PASS), and ii) the last day of each COVID‑19 symptom presentation. Adverse effects were evaluated. The clinical severity for all the patients in the study was mild (88.9%) and moderate (11.1%). The control (placebo) group achieved PASS on day 8.0±1.3, compared with day 4.4±0.8 in the mefenamic acid group (P=0.020, Kaplan‑Meier analyses using log‑rank tests). Patients that received mefenamic acid plus standard medical care had a ~16‑fold higher probability of achieving PASS on day 8 (adjusted RR, 15.57; 95% CI, 1.22‑198.71; P=0.035), compared with the placebo plus standard medical care group. All symptoms lasted for fewer days in the mefenamic acid group, compared with the placebo group; however, only the symptoms of headache (P=0.008), retro‑orbital eye pain (P=0.049), and sore throat (P=0.029) exhibited statistically significant differences. The experimental treatment produced no severe adverse effects. On the whole, the present study demonstrates that the administration of mefenamic acid markedly reduced the symptomatology and time to reach PASS in ambulatory patients with COVID‑19. Due to its probable antiviral effects and potent anti‑inflammatory mechanisms, mefenamic acid may prove to be useful in the treatment of COVID‑19, in combination with other drugs, including the new antivirals (remdesivir, molnupiravir, or favipiravir). However, future studies are also required to confirm these findings.

Patterns of Otorhinolaryngological Manifestations of Covid-19: A Longitudinal Questionnaire-Based Prospective Study in a Tertiary Hospital in Saudi Arabia

Objective:

Many studied investigated the manifestations of COVID-19, yet few described the pattern and severity of otolaryngological symptoms. We aim to describe the picture of COVID-19-associated otorhinolaryngological manifestations and recovery to explore individualized treatment, onward referral, and complications prevention.

Design:

Prospective longitudinal questionnaire-based study.

Setting:

The online questionnaire was filled 3 times through a remote interview over a period of 1 month from June 2020 to July 2020.

Participants:

Patients with confirmed COVID-19 by RT-PCR who were clinically stable.

Main Outcome Measures:

Date of diagnosis, sociodemographic data, and the presence of predictive factors, such as nasal and paranasal disease, anosmia and dysgeusia. Validated tools were used, such as Sino-nasal Outcome Test (SNOT-22), smell test (medical academy screening tool), Voice Handicap Index (VHI), and Reflux Symptoms Index (RSI).

Result:

The questionnaire was sent to 363 patients and the response rate was 70.80% (n = 257). The mean age was 34.58 years (SD = 11.22) and the rate of male participants was 60.7%. The most common otorhinolaryngological symptoms at the time of enrollment was fever (48.6%), whilst the commonest severe symptom was cough (57%). After 1 month, only 11 participants had persistent severe symptoms, especially sleep and psychological symptoms (73%), and the majority were female (63.6%). All of them had at least 1 comorbidity. There was a significant difference between the mean age of participants with severe symptoms (mean = 27.45, SD = 8.39) and without severe symptoms (mean = 34.90, SD = 2.53, t(255) = 2.17, P = .031).

Conclusion:

COVID-19 has a wide-ranged spectrum of presentations, with otorhinolaryngological symptoms being the commonest and most serious. Studying these symptoms is vital to advance management options.

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 241 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 138,897 COVID-19-positive patients, 39.2% reported taste dysfunction (95% confidence interval: 35.34%-43.12%), and the prevalence estimates were slightly but not significantly higher from studies using direct (n = 18) versus self-report (n = 223) methodologies (Q = 0.57, df = 1, P = 0.45). 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.

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 241 meeting all inclusion criteria. Additionally, we explored how methodological differences (direct vs. self-report measures) may affect these estimates. We hypothesized that direct prevalence measures of taste loss would be the most valid because they avoid the taste/smell confusion of self-report. The meta-analysis showed that, among 138,897 COVID-19-positive patients, 39.2% reported taste dysfunction (95% CI: 35.34-43.12%), and the prevalence estimates were slightly but not significantly higher from studies using direct (n = 18) versus self-report (n = 223) methodologies (Q = 0.57, df = 1, p = 0.45). Generally, males reported lower rates of taste loss than did females and taste loss was highest in middle-aged groups. Thus, taste loss is a bona fide symptom COVID-19, meriting further research into the most appropriate direct methods to measure it and its underlying mechanisms.

What can the neurological manifestations of COVID-19 tell us: a meta-analysis

Background

Covid-19 became a global pandemic in 2019. Studies have shown that coronavirus can cause neurological symptoms, but clinical studies on its neurological symptoms are limited. In this meta-analysis, we aimed to summarize the various neurological manifestations that occurred in COVID-19 patients and calculate the incidence of various neurological manifestations. At the same time, we further explored the mechanism of nervous system injury and prognosis in COVID-19 patients in combination with their nervous system manifestations. This study provides a reference for early clinical identification of COVID-19 nervous system injury in the future, so as to achieve early treatment and reduce neurological sequelae.

Methods

We systematically searched all published English literature related to the neurological manifestations of COVID-19 from January 1, 2020, to April 30, 2021, in Pubmed, Embase, and Cochrane Library. The keywords used were COVID-19 and terminology related to the nervous system performance. All included studies were selected by two independent reviewers using EndNote and NoteExpress software, any disagreement was resolved by consensus or by a third reviewer, and the selected data were then collected for meta-analysis using a random-effects model.

Results

A total of 168 articles (n = 292,693) were included in the study, and the meta-analysis showed that the most common neurological manifestations of COVID-19 were myalgia(33%; 95%CI 0.30–0.37; I² = 99.17%), smell impairment(33%; 95%CI 0.28–0.38; I² = 99.40%), taste dysfunction(33%; 95%CI 0.27–0.39; I² = 99.09%), altered mental status(32%; 95%CI 0.22–0.43; I² = 99.06%), headache(29%; 95%CI 0.25–0.33; I² = 99.42%), encephalopathy(26%; 95%CI 0.16–0.38; I² = 99.31%), alteration of consciousness(13%; 95%CI 0.08–0.19; I² = 98.10%), stroke(12%; 95%CI 0.08–0.16; I² = 98.95%), dizziness(10%; 95%CI 0.08–0.13; I² = 96.45%), vision impairment(6%; 95%CI 0.03–0.09; I² = 86.82%), intracerebral haemorrhage(5%; 95%CI 0.03–0.09; I² = 95.60%), seizure(4%; 95%CI 0.02 -0.05; I² = 98.15%), encephalitis(2%; 95%CI 0.01–0.03; I² = 90.36%), Guillan-Barré Syndrome (GBS) (1%; 95%CI 0.00–0.03; I² = 89.48%).

Conclusions

Neurological symptoms are common and varied in Covid-19 infections, and a growing number of reports suggest that the prevalence of neurological symptoms may be increasing. In the future, the role of COVID-19 neurological symptoms in the progression of COVID-19 should be further studied, and its pathogenesis and assessment methods should be explored, to detect and treat early neurological complications of COVID-19 and reduce mortality.

Olfactory and gustatory dysfunctions in SARS-CoV-2 infection: A systematic review

BACKGROUND

Among Coronavirus Disease 2019 (COVID-19) manifestations, Olfactory (OD) and Gustatory (GD) Dysfunctions (OGD) have drawn considerable attention, becoming a sort of hallmark of the disease. Many have speculated on the pathogenesis and clinical characteristics of these disturbances; however, no definite answers have been produced on the topic. With this systematic review, we aimed to collect all the available evidence regarding the prevalence of OGD, the timing of their onset and their resolution, their rate of recovery and their role as diagnostic and prognostic tools for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection.

METHODS

A systematic review comprising all the observational studies that reported the prevalence and/or the longitudinal trajectories of OGD in COVID-19 patients, as self-reported by patients or measured through objective psychophysical tests.

RESULTS

After the selection process, 155 studies were included, with a total of 70,920 patients and 105,291 not-infected individuals. Prevalence reports were extremely variable across studies, with wide ranges for OD (0%-98%) and GD (0-89%) prevalence. OGD occurred early during the disease course and only rarely preceded other symptoms; out of 30 studies with a follow-up time of at least 20 days, only in 5 studies OGD fully resolved in more than 90% of patients. OGD had low sensitivity and high specificity for SARS-CoV-2 infection; accuracy of OD and GD for infection identification was higher than 80% in 10 out of 33 studies and in 8 out of 22 studies considered, respectively. 28 out of 30 studies that studied the association between OGD and disease severity found how OGD were associated with lower rates of severe pneumonia, hospitalization and mortality.

CONCLUSIONS

OGD seem to be highly prevalent in SARS-CoV-2 infection. They occur early, concomitantly with other symptoms and often persist after recovery, in some cases for months; whether a full recovery eventually occurs in all cases is not clear yet. OGD are good predictors of SARS-CoV-2 infection and are associated with a milder disease course.

Gustatory dysfunction in COVID-19 patients: a rapid systematic review on 27,687 cases

Objective: This is a rapid systematic review concerning taste alterations in 27,687 individuals infected with SARS-CoV-2, published in the worldwide literature.Material and methods: Of the 485 articles recovered, 67 eligible studies (27,687 confirmed COVID-19 cases) were included in this analysis. We analysed the prevalence of the taste alterations in patients considering the country of origin of the studies.Results: The results show strong important differences in the overall reported prevalence of taste alterations among the different countries (from 11% of Korea to 88.8% of Belgium).Conclusions: These data highlight that there is a different geographical distribution of taste alterations in COVID-19 patients. Gustatory dysfunction seems to be an understudied symptom of COVID-19 and this may explain the inconsistencies of diagnostic criteria for COVID-19 case definition. Furthermore, this diagnostic underestimation can lead to an increased risk of contagion for the whole population and for the working classes most at risk, including the dental one.

Is loss of smell an early predictor of COVID-19 severity: a systematic review and meta-analysis

Anecdotal evidence suggests that the severity of coronavirus disease of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is likely to be distinguished by variations in loss of smell (LOS). Thus, we conducted a meta-analysis of 45 articles that include a total of 42,120 COVID-19 patients from 17 different countries to demonstrate that severely ill or hospitalized COVID-19 patients have a lesser chance of experiencing LOS than non-severely ill or non-hospitalized COVID-19 patients (odds ratio = 0.527 [95% CI 0.373–0.744; p < 0.001] and 0.283 [95% CI 0.173–0.462; p < 0.001], respectively). We also proposed a possible mechanism underlying the association of COVID-19 severity with anosmia, which may explain why patients without sense of smell develop severe COVID-19. Variations in LOS according to the severity of COVID-19 is a global phenomenon, with few exceptions. Since severely ill patients have a lower rate of anosmia, patients without anosmia should be monitored more closely in the early stages of COVID-19, for early diagnosis of severity of illness. An understanding of how the severity of COVID-19 infection and LOS are associated has profound implications for the clinical management and mitigation strategies for the disease.

Correlation Analysis Between Serum Uric Acid, Prealbumin Level, Lactate Dehydrogenase, and Severity of COVID-19

Objective: To analyze the correlation between serum uric acid, prealbumin levels, lactate dehydrogenase (LDH), and the severity of COVID-19.

Methods: The data from 135 patients with COVID-19 was collected, and the patients were divided into a non-severe group (110 cases) and a severe group (25 cases), according to the severity of illness. Sixty cases with normal physical examinations over the same period and 17 cases diagnosed with other viral pneumonia in the past five years were selected as the control group to analyze the correlation between the detection index and the severity of COVID-19.

Results: Serum albumin and prealbumin in the severe group were significantly lower than those in the non-severe group (p < 0.01); serum uric acid in the severe group was lower than that in the non-severe group (p < 0.05). LDH and C-reaction protein (CRP) in the severe group were higher than those in non-severe group (p < 0.01); the levels of albumin, prealbumin, serum uric acid, and LDH in the severe group were significantly different from those in healthy control group (p < 0.01) and the levels of prealbumin, serum uric acid, LDH, and CRP in the severe group were significantly different from those in the other viral pneumonia group (p < 0.01). Serum albumin and prealbumin were positively correlated with the oxygenation index (p < 0.001), while LDH was negatively correlated with oxygenation index (p < 0.001).

Conclusion: Serum albumin, prealbumin, the oxygenation index, and LDH are risk factors of COVID-19.

Taste alteration in COVID-19: Significant geographical differences exist in the prevalence of the symptom

Early detection of COVID-19 is important for reduction in the spread of the disease and gustatory disturbances (GD) are known to have a strong predictive value. In the present study, we aimed to map the geographical differences in the prevalence of GD in individuals infected with SARS-CoV-2 during the first wave of COVID-19 in order to improve case identification and to facilitate prioritization. We undertook a rapid scoping review of articles published in the repository of the National Library of Medicine (MEDLINE/PubMed) and medRxiv from their inception until 3^rd September, 2020. The minimum requirements for completing a restricted systematic review were fulfilled. Of the 431 articles retrieved, 61 studies (28,374 cases confirmed with COVID-19) from 20 countries were included in the analysis. GD were most prevalent in the Americas [66.78%, 95% CI 54.77–78.79%] compared to Europe [57.18%, 95% CI 52.35–62.01%], the Middle East [38.83%, 95% CI 27.47–50.19%] and East Asia [13.1%, 95% CI 0.14–26.06%]. No differences of GD prevalence were evident between February and August 2020. The data demonstrate that there is a marked geographical distribution of GD in COVID-19 patients which, possibly, might be explained by differences in diagnostic criteria for COVID-19 case definition during the early phase of the pandemic.

Respirators, face masks, and their risk reductions via multiple transmission routes for first responders within an ambulance

First responders may have high SARS-CoV-2 infection risks due to working with potentially infected patients in enclosed spaces. The study objective was to estimate infection risks per transport for first responders and quantify how first responder use of N95 respirators and patient use of cloth masks can reduce these risks. A model was developed for two Scenarios: an ambulance transport with a patient actively emitting a virus in small aerosols that could lead to airborne transmission (Scenario 1) and a subsequent transport with the same respirator or mask use conditions, an uninfected patient; and remaining airborne SARS-CoV-2 and contaminated surfaces due to aerosol deposition from the previous transport (Scenario 2). A compartmental Monte Carlo simulation model was used to estimate the dispersion and deposition of SARS-CoV-2 and subsequent infection risks for first responders, accounting for variability and uncertainty in input parameters (i.e., transport duration, transfer efficiencies, SARS-CoV-2 emission rates from infected patients, etc.). Infection risk distributions and changes in concentration on hands and surfaces over time were estimated across sub-Scenarios of first responder respirator use and patient cloth mask use. For Scenario 1, predicted mean infection risks were reduced by 69%, 48%, and 85% from a baseline risk (no respirators or face masks used) of 2.9 × 10-2 ± 3.4 × 10-2 when simulated first responders wore respirators, the patient wore a cloth mask, and when first responders and the patient wore respirators or a cloth mask, respectively. For Scenario 2, infection risk reductions for these same Scenarios were 69%, 50%, and 85%, respectively (baseline risk of 7.2 × 10-3 ± 1.0 × 10-2). While aerosol transmission routes contributed more to viral dose in Scenario 1, our simulations demonstrate the ability of face masks worn by patients to additionally reduce surface transmission by reducing viral deposition on surfaces. Based on these simulations, we recommend the patient wear a face mask and first responders wear respirators, when possible, and disinfection should prioritize high use equipment.

Safety and efficacy of a COVID-19 treatment with nebulized and/or intravenous neutral electrolyzed saline combined with usual medical care vs. usual medical care alone: A randomized, open-label, controlled trial

Coronavirus disease 2019 (COVID-19) is currently the major public health problem worldwide. Neutral electrolyzed saline solution that contains reactive chlorine and oxygen species may be an effective therapeutic. In the present study, the treatment efficacy of intravenous and/or nebulized neutral electrolyzed saline combined with usual medical care vs. usual medical care alone was evaluated in ambulatory patients with COVID-19. A prospective, 2-arm, parallel-group, randomized, open-label, multi-center, phase I-II clinical trial including 214 patients was performed. The following two outcomes were evaluated during the 20-day follow-up: i) The number of patients with disease progression; and ii) the patient acceptable symptom state. Serial severe acute respiratory syndrome coronavirus 2 naso/oro-pharyngeal detection by reverse transcription-quantitative (RT-q) PCR was performed in certain patients of the experimental group. Biochemical and hematologic parameters, as well as adverse effects, were also evaluated in the experimental group. The experimental treatment decreased the risk of hospitalization by 89% [adjusted relative risk (RR)=0.11, 95% confidence interval (CI): 0.03-0.37, P<0.001] and the risk of death by 96% (adjusted RR=0.04, 95% CI: 0.01-0.42, P=0.007) and also resulted in an 18-fold higher probability of achieving an acceptable symptom state on day 5 (adjusted RR=18.14, 95% CI: 7.29-45.09, P<0.001), compared with usual medical care alone. Overall, neutral electrolyzed saline solution was better than usual medical care alone. Of the patients analyzed, >50% were negative for the virus as detected by RT-qPCR in naso/oro-pharyngeal samples on day 4, with only a small number of positive patients on day 6. Clinical improvement correlated with a decrease in C-reactive protein, aberrant monocytes and increased lymphocytes and platelets. Cortisol and testosterone levels were also evaluated and a decrease in cortisol levels and an increase in the testosterone-cortisol ratio were observed on days 2 and 4. The experimental treatment produced no serious adverse effects. In conclusion, neutral electrolyzed saline solution markedly reduced the symptomatology and risk of progression in ambulatory patients with COVID-19. The present clinical trial was registered in the Cuban public registry of clinical trials (RPCEC) database (May 5, 2020; no. TX-COVID19: RPCEC00000309).

Comprehensive Review on Neuro-COVID-19 Pathophysiology and Clinical Consequences

Aside from the respiratory distress as the predominant clinical presentation of SARS-CoV-2 infection, various neurological complications have been reported with the infection during the ongoing pandemic, some of which cause serious morbidity and mortality. Herein, we gather the latest anatomical evidence of the virus's presence within the central nervous system. We then delve into the possible SARS-CoV-2 entry routes into the neurological tissues, with the hematogenous and the neuronal routes as the two utmost passage routes into the nervous system. We then give a comprehensive review of the neurological manifestations of the SARS-CoV-2 invasion in both the central and peripheral nervous system and its underlying pathophysiology via investigating large studies in the field and case reports in cases of study scarcity.

Incidence of Sino-Nasal Symptoms in COVID-19 Patients

Corona virus disease was first reported in December 2019 in Wuhan, China and is spreading across the world in an alarming fashion. To contain the spread, it is very important to identify the subtle/not readily apparent symptoms of COVID-19 at the earliest. The aim of the study is to determine the incidence duration progress of sino-nasal symptoms in COV 2 positive patients using SNAQ scoring. Patients who tested positive for SARS-COV 2 by RT-PCR and admitted in our hospital under category A (n = 382) were included in the study. A detailed history was collected from all the patients and sino-nasal assessment questionnaire (SNAQ) was provided to the patient with complaints of sinonasal symptoms and they were asked to fill the forms on day 3, 7 and 14. To identify the characteristics of sinonasal symptoms in COVID-19 patients with a history of smoking, smoking history was also collected in detail and patients were classified based on Brinkman’s index into mild, moderate and severe smokers. In this study, the incidence of sinonasal symptoms was 24%. Average SNAQ scoring on day 3 was 30.09 and on day 7 was 12.9 and day 14 is 3.8. There was a decline in score on day 7 compared to day 3 indicating symptoms decrease by day7. Average SNAQ scoring in non-smokers and mild and moderate smokers was 20.18, 34.11, 57.5 respectively. The SNAQ scoring in smokers was more than that of non-smokers and was also persistent for a longer duration compared to non-smokers. Sino-nasal symptoms catch our eye because it is an important route for transmission. Viral shedding from sinonasal tract may be an important source for transmission. History and degree of smoking should also be considered while dividing COVID-19 patients into categories.

MSC-derived exosomes carrying a cocktail of exogenous interfering RNAs an unprecedented therapy in era of COVID-19 outbreak

BACKGROUND

The onset of the SARS-CoV-2 pandemic has resulted in ever-increasing casualties worldwide, and after 15 months, standard therapeutic regimens are yet to be discovered.

MAIN BODY

Due to the regenerative and immunomodulatory function of MSCs, they can serve as a suitable therapeutic option in alleviating major COVID-19 complications like acute respiratory distress syndrome. However, the superior properties of their cognate exosomes as a cell-free product make them preferable in the clinic. Herein, we discuss the current clinical status of these novel therapeutic strategies in COVID-19 treatment. We then delve into the potential of interfering RNAs incorporation as COVID-19 gene therapy and introduce targets involved in SARS-CoV-2 pathogenesis. Further, we present miRNAs and siRNAs candidates with promising results in targeting the mentioned targets.

CONCLUSION

Finally, we present a therapeutic platform of mesenchymal stem cell-derived exosomes equipped with exogenous iRNAs, that can be employed as a novel therapeutic modality in COVID-19 management aiming to prevent further viral spread within the lung, hinder the virus life cycle and pathogenesis such as immune suppression, and ultimately, enhance the antiviral immune response.

One year on: an updated systematic review of SARS-CoV-2, COVID-19 and audio-vestibular symptoms

OBJECTIVE

The aim was to systematically review the literature to December 2020, in order to provide a timely summary of evidence on SARS-CoV-2, COVID-19 and audio-vestibular symptoms.

DESIGN

The protocol was registered in the International Prospective Register of Systematic Reviews. The methods were developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Risk of bias was assessed using the National Institutes of Heath quality assessment tools.

STUDY SAMPLE

After rejecting 850 records, 28 case reports/series and 28 cross-sectional studies met the inclusion criteria.

RESULTS

There are multiple reports of hearing loss (e.g. sudden sensorineural), tinnitus and rotatory vertigo in adults having a wide range of COVID-19 symptom severity. The pooled estimate of prevalence based primarily on retrospective recall of symptoms, was 7.6% (CI: 2.5-15.1), 14.8% (CI: 6.3-26.1) and 7.2% (CI: 0.01-26.4), for hearing loss, tinnitus and rotatory vertigo, respectively. However, these could be an over-estimate because it was not always clear that studies report a change in symptom.

CONCLUSION

There are multiple reports of audio-vestibular symptoms associated with COVID-19. However, there is a dearth of high-quality studies comparing COVID-19 cases and controls.

REVIEW REGISTRATION

Prospective Register of Systematic Reviews (PROSPERO); registration number CRD42020227038).

Oral Symptoms Associated with COVID-19 and Their Pathogenic Mechanisms: A Literature Review

Since the worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, management of coronavirus disease 2019 (COVID-19) has been challenging for healthcare providers. The oral cavity is referred to as a target of SARS-CoV-2. The aim of this study was to review oral symptoms specific to COVID-19 patients from the point of view of symptom prevalence and pathogenesis and to speculate the pathogenic mechanisms underlying them. Scientific articles were retrieved by searching PubMed/MEDLINE, Google Scholar, medRxiv, and bioRxiv from 3 February 2020 to 31 December 2020, and they were reviewed by title, abstract, and text for relevance. The literature search indicated that COVID-19 patients frequently present with gustatory dysfunction, xerostomia, and oral mucosal lesions, while their prevalence is likely to vary by country, age, gender, and disease severity. Gustatory dysfunction and xerostomia appear at an early stage of SARS-CoV-2 infection and last relatively long. One of possible pathogenic mechanisms of both symptoms is attributed to the expression of viral cellular entry-relevant receptors in taste cells and salivary glands. Dental professionals who can first become aware of oral symptoms associated with COVID-19 will play a more active role in and make a greater contribution to diagnosis and prevention of COVID-19.

Prevalence of Otorhinolaryngological Symptoms in Covid 19 Patients

To determine prevelance of ENT symptoms in COVID 19 positive patients. A cross sectional study was performed at SRTR GMC AMBAJOGAI, a tertiary care hospital amongst the patients admitted in COVID 19 isolation ward with a positive RT-PCR report. Amongst the included 180 patients, 112 patients had one or more ENT related symptoms that included throat pain (47.2%), loss of smell (55.5%), loss of taste (58.8%) and hearing loss (54.44%) along with generalized COVID 19 symptoms. ENT symptoms can be considered as biomarkers for early diagnosis of Covid-19 patients ensuring faster treatment and isolation allowing better containment of the disease.

Functional capacity and rehabilitation strategies in Covid-19 patients: current knowledge and challenges

Covid-19 is a novel infectious disease whose spectrum of presentation ranges from absence of symptoms to widespread interstitial pneumonia associated with severe acute respiratory syndrome (SARS), leading to significant mortality. Given the systemic pattern of Covid-19, there are many factors that can influence patient's functional capacity after acute infection and the identification of such factors can contribute to the development of specific rehabilitation strategies. Pulmonary impairment is the primary cause of hospitalization due to Covid-19, and can progress to SARS as well as increase length of hospitalization. Moreover, cardiac involvement is observed in approximately 30% of hospitalized patients, with an increased risk of acute myocarditis, myocardial injury, and heart failure, which may compromise functional capacity in the long-term. Thromboembolic complications have also been reported in some patients with Covid-19 and are associated with a poor prognosis. Musculoskeletal complications may result from long periods of hospitalization and immobility, and can include fatigue, muscle weakness and polyneuropathy. Studies that address the functional capacity of patients after Covid-19 infection are still scarce. However, based on knowledge from the multiple systemic complications associated with Covid-19, it is reasonable to suggest that most patients, especially those who underwent prolonged hospitalization, will need a multiprofessional rehabilitation program. Further studies are needed to evaluate the functional impact and the rehabilitation strategies for patients affected by Covid-19.

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

Background: 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. Methods: 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. Results: 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, p < 0.001) and that of dysgeusia was 8.6-fold higher (OR: 8.61; 95% CI: 5.26, 14.11, p < 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. Conclusion: 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. Protocol registration: PROSPERO CRD42020223204.