Features of anosmia in COVID-19

The diagnostic value of detecting sudden smell loss among asymptomatic COVID-19 patients in early stage: The possible early sign of COVID-19

IMPORTANCE

The newly emerged coronavirus disease 19 (COVID-19), is threatening the world. Olfactory or gustatory dysfunction is reported as one of the symptoms worldwide. As reported so far, different clinical features have been reported according to outbreak sites and gender; most of the patients, who complained of anosmia or hyposmia, were Europeans. We had a fast review for novel articles about COVID-19 infection and olfactory function.

OBSERVATIONS

Rapid reviews for COVID-19 or other viral infection and olfactory and/or gustatory dysfunctions were done in this review. Up to date, a lot of reports have shown that olfactory dysfunction is related to viral infections but no exact mechanism, clinical course, and definite treatment have been discovered, which is also same in COVID-19. In general, intranasal steroid (INS) and oral steroid for short time help improve the recovery of the olfactory function in case of olfactory dysfunction after virus infection. Considering severe respiratory complications and immunocompromised state of COVID-19, the use of steroid should be limited and cautious because we do not have enough data to support the usage of steroid to treat olfactory dysfunction in the clinical course of COVID-19.

CONCLUSIONS AND RELEVANCE

In the days of pandemic COVID-19, we should keep in mind that olfactory dysfunctions, even without other upper respiratory infection or otolaryngologic symptoms, might be the early signs of COVID-19.

Diagnosing COVID-19 in the Emergency Department: A Scoping Review of Clinical Examinations, Laboratory Tests, Imaging Accuracy, and Biases

Objective

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) emerged as a global pandemic in early 2020 with rapidly evolving approaches to diagnosing the clinical illness called coronavirus disease (COVID‐19). The primary objective of this scoping review is to synthesize current research of the diagnostic accuracy of history, physical examination, routine laboratory tests, real‐time reverse transcription–polymerase chain reaction (rRT‐PCR), immunology tests, and computed tomography (CT) for the emergency department (ED) diagnosis of COVID‐19. Secondary objectives included a synopsis of diagnostic biases likely with current COVID‐19 research as well as corresponding implications of false‐negative and false‐positive results for clinicians and investigators.

Methods

A Preferred Reporting Items for Systematic Reviews and Meta‐Analyses–Scoping Review (PRISMA‐ScR)–adherent synthesis of COVID‐19 diagnostic accuracy through May 5, 2020, was conducted. The search strategy was designed by a medical librarian and included studies indexed by PubMed and Embase since January 2020.

Results

A total of 1,907 citations were screened for relevance. Patients without COVID‐19 are rarely reported, so specificity and likelihood ratios were generally unavailable. Fever is the most common finding, while hyposmia and hypogeusia appear useful to rule in COVID‐19. Cough is not consistently present. Lymphopenia is the mostly commonly reported laboratory abnormality and occurs in over 50% of COVID‐19 patients. rRT‐PCR is currently considered the COVID‐19 criterion standard for most diagnostic studies, but a single test sensitivity ranges from 60% to 78%. Multiple reasons for false‐negatives rRT‐PCR exist, including sample site tested and disease stage during which sample was obtained. CT may increase COVID‐19 sensitivity in conjunction with rRT‐PCR, but guidelines for imaging patients most likely to benefit are emerging. IgM and IgG serology levels are undetectable in the first week of COVID‐19, but sensitivity (range = 82% to 100%) and specificity (range = 87% to 100%) are promising. Whether detectable COVID‐19 antibodies correspond to immunity remains unanswered. Current studies do not adhere to accepted diagnostic accuracy reporting standards and likely report significantly biased results if the same tests were to be applied to general ED populations with suspected COVID‐19.

Conclusions

With the exception of fever and disorders of smell/taste, history and physical examination findings are unhelpful to distinguish COVID‐19 from other infectious conditions that mimic SARS‐CoV‐2 like influenza. Routine laboratory tests are also nondiagnostic, although lymphopenia is a common finding and other abnormalities may predict severe disease. Although rRT‐PCR is the current criterion standard, more inclusive consensus‐based criteria will likely emerge because of the high false‐negative rate of PCR tests. The role of serology and CT in ED assessments remains undefined.

The Neurologic Manifestations of Coronavirus Disease 2019

The coronavirus disease 2019 (COVID-19) is an ongoing global pandemic that has so far affected 216 countries and more than 5 million individuals worldwide. The infection is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While pulmonary manifestations are the most common, neurological features are increasingly being recognized as common manifestations of the COVID-19, especially in the cases of severe infection. These include acute cerebrovascular disease, encephalitis, and Guillain-Barre syndrome (GBS). Here, we review the neuropathogenesis of SARS-CoV-2 and the central and peripheral nervous system manifestations of COVID-19.

Prevalence of New Onset Anosmia in COVID-19 Patients: Is The Trend Different Between European and Indian Population?

COVID-19 outbreak is major pandemic affecting lakhs of people all across the globe. Along with other nonspecific clinical features, reports mention anosmia to be an important symptom in COVID-19 positive patients. To study the prevalence of anosmia in confirmed COVID-19 patients, in Indian population and to ascertain its significance as a symptom of COVID 19. Study was done at a tertiary care COVID treating hospital. While eliciting detailed history from Covid-19 positive patients, all patients were asked about symptom of anosmia. Same was asked from control group of subjects who were COVID-19 negative. The history of anosmia was also elicited on discharge after the patients tested negative for COVID-19. 74 patients formed part of the study. 11 of 74 (14.8%) patients had anosmia. On using the chi square test for significance the difference was significant (p < .01), suggesting anosmia to be a significant clinical feature in COVID-19 patients. On comparing with world literature it was observed that the prevalence of anosmia is higher in European population as compared to Indian Also the symptom of anosmia improved when the patient recovered from the disease. Prevalence of new onset anosmia in Indian population with COVID-19 is 14.8%. Symptom of anosmia in present times should be considered as a important clinical feature and should raise a suspicion of COVID-19. The prevalence of anosmia in Indian population is much lesser than that reported in European population.

Taste and Smell Impairment in SARS-CoV-2 Recovers Early and Spontaneously: Experimental Data Strongly Linked to Clinical Data

A growing body of literature indicates that smell and taste impairment has frequently occurred during the Severe Acute Respiratory Syndrome (SARS)-like Coronavirus (SARS-CoV-2) outbreak. Experimental studies have mostly found that non-neural-type cells are responsible for SARS-CoV-2-related taste and smell impairment. If this is the case, smell/taste impairment needs to recover early. Literature data from clinical studies indicated a strong correlation between experimental and clinical findings. This article presents clinical studies related to SARS-CoV-2-induced smell/taste impairment that reported recovery rates. Experimental researchers may use these data to observe the dynamics of smell impairment and implement these findings in their research (e.g., correct timing of sampling) to perform further studies.

[Anosmia without aguesia in COVID-19 patients: about 2 cases]

During the ongoing pandemic, anosmia, whether or not associated with aguesia, has been a common symptom in patients with SARS-CoV-2 infection causing COVID-19. We here report two cases of anosemia without aguesia in adults with COVID-19. The onset was brutal and symptomsa persisted for a few weeks after healing. The patients presented to the ENT Department where they received no therapy and underwent outpatient surveillance. After 5 weeks, patients reported they had recovered the sense of smell. This study highlights that anosmia can occur without aguesia and persist after healing in COVID-19 patients. Recovery of the smell is possible after a few weeks without medical treatment. That is why, patients follow-up is essential in subjects recovered from COVID-19 to better understand the course of persistent symptoms.

Does COVID-19 cause permanent damage to olfactory and gustatory function?

The objective of this study was to investigate the status of COVID-19 patients with sudden anosmia and dysgeusia using an olfactory dysfunction questionnaire highlighting recovery times. This prospective study included 75 patients who completed a patient-reported outcome questionnaire. Among these, 46 patients completed an olfactory evaluation based on the duration of anosmia and dysgeusia. The olfactory evaluation revealed that 24% (N = 18) of patients had mild hyposmia, 13% (N = 10) had moderate hyposmia, 30% (N = 23) had severe hyposmia, 32% (N = 24) had anosmia, and 100% had dysgeusia (N = 75). The viral load significantly decreased throughout the 17 days following the onset of the olfactory disorder. The purpose of this study was to understand whether patients with COVID-19 can recover olfactory and gustatory function, in contrast to patients with other rhinoviruses and inflammatory diseases such as rhinosinusitis chronic and rhinosinusitis with polyps. These preliminary clinical findings indicate that the relatively rapid recovery of olfactory and gustative function can mean a resolution of viral infection in most patients. The present study suggests that coronavirus can induce olfactory dysfunction but not permanent damage. Olfactory and gustatory functional impairment has been recognized as a hallmark of COVID-19 and may be an important predictor of clinical outcome. Our study supports the need to add anosmia and dysgeusia to the list of symptoms used in screening tools for possible COVID-19 infection.

Objective sensory testing methods reveal a higher prevalence of olfactory loss in COVID-19-positive patients compared to subjective methods: A systematic review and meta-analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has currently infected over 6.5 million people worldwide. In response to the pandemic, numerous studies have tried to identify causes and symptoms of the disease. Emerging evidence supports recently acquired anosmia (complete loss of smell) and hyposmia (partial loss of smell) as symptoms of COVID-19, but studies of olfactory dysfunction show a wide range of prevalence, from 5% to 98%. We undertook a search of Pubmed/Medline and Google Scholar with the keywords "COVID-19," "smell," and/or "olfaction." We included any study that quantified olfactory loss as a symptom of COVID-19. Studies were grouped and compared based on the type of method used to measure smell loss-subjective measures such as self-reported smell loss versus objective measures using rated stimuli-to determine if prevalence rate differed by method type. For each study, 95% confidence intervals (CIs) were calculated from point estimates of olfactory disturbance rates. We identified 34 articles quantifying anosmia as a symptom of COVID-19, collected from cases identified from January 16 to April 30, 2020. The pooled prevalence estimate of smell loss was 77% when assessed through objective measurements (95% CI of 61.4-89.2%) and 45% with subjective measurements (95% CI of 31.1-58.5%). Objective measures are a more sensitive method to identify smell loss as a result of infection with SARS-CoV-2; the use of subjective measures, while expedient during the early stages of the pandemic, underestimates the true prevalence of smell loss.

Systematic Review and Meta-analysis of Smell and Taste Disorders in COVID-19

OBJECTIVE

Loss of smell and taste are considered potential discriminatory symptoms indicating triaging for coronavirus disease 2019 (COVID-19) and early case identification. However, the estimated prevalence essential to guide public health policy varies in published literature. This meta-analysis aimed to estimate prevalence of smell and taste loss among COVID-19 patients.

DATA SOURCES

We conducted systematic searches of PubMed, Embase, Web of Science, and Google Scholar databases for studies published on the prevalence of smell and taste loss in COVID-19 patients.

REVIEW METHODS

Two authors extracted data on study characteristics and the prevalence of smell and taste loss. Random-effects modeling was used to estimate pooled prevalence. Subgroup analysis and meta-regression were conducted to explore potential heterogeneity sources. This study used PRISMA and MOOSE guidelines.

RESULTS

Twenty-seven of 32 studies reported a prevalence of loss of smell, taste, or both from a combined sample of 20,451 COVID-19 patients. The estimated global pooled prevalence of loss of smell among 19,424 COVID-19 patients from 27 studies was 48.47% (95% CI, 33.78%-63.29%). Loss of taste was reported in 20 studies and 8001 patients with an estimated pooled prevalence of 41.47% (95% CI, 3.13%-31.03%), while 13 studies that reported combined loss of smell and taste in 5977 COVID-19 patients indicated a pooled prevalence of 35.04% (95% CI, 22.03%-49.26%).

CONCLUSIONS

The prevalence of smell and taste loss among COVID-19 patients was high globally, and regional differences supported the relevance of these symptoms as important markers. Health workers must consider them as suspicion indices for empirical diagnosis of severe acute respiratory syndrome coronavirus 2 infection.

Olfactory and gustatory function impairment in COVID-19 patients: Italian objective multicenter-study

BACKGROUND

Objective data on chemosensitive disorders during COVID-19 are lacking in the Literature.

METHODS

Multicenter cohort study that involved four Italian hospitals. Three hundred and forty-five COVID-19 patients underwent objective chemosensitive evaluation.

RESULTS

Chemosensitive disorders self-reported by 256 patients (74.2%) but the 30.1% of the 89 patients who did not report dysfunctions proved objectively hyposmic. Twenty-five percentage of patients were seen serious long-lasting complaints. All asymptomatic patients had a slight lowering of the olfactory threshold. No significant correlations were found between the presence and severity of chemosensitive disorders and the severity of the clinical course. On the contrary, there is a significant correlation between the duration of the olfactory and gustatory symptoms and the development of severe COVID-19.

CONCLUSIONS

Patients under-report the frequency of chemosensitive disorders. Contrary to recent reports, such objective testing refutes the proposal that the presence of olfactory and gustatory dysfunction may predict a milder course, but instead suggests that those with more severe disease neglect such symptoms in the setting of severe respiratory disease.

Genetic gateways to COVID-19 infection: Implications for risk, severity, and outcomes

The dynamics, such as transmission, spatial epidemiology, and clinical course of Coronavirus Disease-2019 (COVID-19) have emerged as the most intriguing features and remain incompletely understood. The genetic landscape of an individual in particular, and a population in general seems to play a pivotal role in shaping the above COVID-19 dynamics. Considering the implications of host genes in the entry and replication of SARS-CoV-2 and in mounting the host immune response, it appears that multiple genes might be crucially involved in the above processes. Herein, we propose three potentially important genetic gateways to COVID-19 infection; these could explain at least in part the discrepancies of its spread, severity, and mortality. The variations within Angiotensin-converting enzyme 2 (ACE2) gene might constitute the first genetic gateway, influencing the spatial transmission dynamics of COVID-19. The Human Leukocyte Antigen locus, a master regulator of immunity against infection seems to be crucial in influencing susceptibility and severity of COVID-19 and can be the second genetic gateway. The genes regulating Toll-like receptor and complement pathways and subsequently cytokine storm induced exaggerated inflammatory pathways seem to underlie the severity of COVID-19, and such genes might represent the third genetic gateway. Host-pathogen interaction is a complex event and some additional genes might also contribute to the dynamics of COVID-19. Overall, these three genetic gateways proposed here might be the critical host determinants governing the risk, severity, and outcome of COVID-19. Genetic variations within these gateways could be key in influencing geographical discrepancies of COVID-19.

Treatment of post-viral olfactory dysfunction: an evidence-based review with recommendations

Background

Post‐viral olfactory dysfunction (PVOD) is one of the most common causes of olfactory loss. Despite its prevalence, optimal treatment strategies remain unclear. This article provides a comprehensive review of PVOD treatment options and provides evidence‐based recommendations for their use.

Methods

A systematic review of the Medline, Embase, Cochrane, Web of Science, Scopus, and Google Scholar databases was completed according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. Studies with defined olfactory outcomes of patients treated for PVOD following medical, surgical, acupuncture, or olfactory training interventions were included. The Clinical Practice Guideline Development Manual and Conference on Guideline Standardization (COGS) instrument recommendations were followed in accordance with a previously described, rigorous, iterative process to create an evidence‐based review with recommendations.

Results

From 552 initial candidate articles, 36 studies with data for 2183 patients with PVOD were ultimately included. The most common method to assess olfactory outcomes was Sniffin’ Sticks. Broad treatment categories included: olfactory training, systemic steroids, topical therapies, a variety of heterogeneous non‐steroidal oral medications, and acupuncture.

Conclusion

Based on the available evidence, olfactory training is a recommendation for the treatment of PVOD. The use of short‐term systemic and/or topical steroids is an option in select patients after careful consideration of potential risks of oral steroids. Though some pharmacological investigations offer promising preliminary results for systemic and topical medications alike, a paucity of high‐quality studies limits the ability to make meaningful evidence‐based recommendations for the use of these therapies for the treatment of PVOD.

Olfactory and gustatory abnormalities in COVID-19 cases

Purpose

At the time of writing, there is a pandemic affecting virtually every country on Earth. There is considerable discussion amongst clinicians as well as lay people about anosmia and ageusia in COVID-19 sufferers. We aimed to report the results from comprehensive olfactory and gustatory testing in a series of hospital in-patients.

Methods

The prospective study evaluated 81 individuals with a COVID-19 infection, as confirmed by 2019 n-cov Real-Time PCR laboratory testing. The control group consisted of forty individuals with COVID-19 negative. Olfactory and gustatory testings were carried out by an examiner utilizing stringent safety standards and wearing full personal protective equipment. The results obtained in the case group were then compared with those obtained for the controls.

Results

In the case group, 41(50.6%) of patients were male and 40 (49.4%) were female, mean age of 54.16 ± 16.98 years (18–95). In the control group, 21 (52.5%) of subjects were male and 19 (47.5%) were female, and mean age was 55 ± 15.39 years (18–90). Fifty (61.7%) COVID-19-positive patients had complaints related to olfaction. The distribution of olfactory symptoms in the case group differed at the level of statistical significance from the control group (p < 0.001). Turning to gustatory abnormalities, within the case group, 22 individuals (27.2%) had taste malfunction. A statistically significant difference was found in the distribution of gustatory abnormalities between cases and controls (p < 0.001).

Conclusions

Olfactory and gustatory dysfunctions are strongly associated with SARS-CoV-2 infection. Hyposmia with or without hypogeusia is potentially a reliable indicator of latent COVID-19.

Prevalence of Chemosensory Dysfunction in COVID-19 Patients: A Systematic Review and Meta-analysis Reveals Significant Ethnic Differences

A significant fraction of people who test positive for COVID-19 have chemosensory deficits. However, the reported prevalence of these deficits in smell and/or taste varies widely, and the reason for the differences between studies is unclear. We determined the pooled prevalence of such chemosensory deficits in a systematic review. We searched the COVID-19 portfolio of the National Institutes of Health for all studies that reported the prevalence of smell and/or taste deficits in patients diagnosed with COVID-19. Forty-two studies reporting on 23,353 patients qualified and were subjected to a systematic review and meta-analysis. Estimated random prevalence of olfactory dysfunction was 38.5%, of taste dysfunction was 30.4% and of overall chemosensory dysfunction was 50.2%. We examined the effects of age, disease severity, and ethnicity on chemosensory dysfunction. The effect of age did not reach significance, but anosmia/hypogeusia decreased with disease severity, and ethnicity was highly significant: Caucasians had a 3-6 times higher prevalence of chemosensory deficits than East Asians. The finding of ethnic differences points to genetic, ethnicity-specific differences of the virus-binding entry proteins in the olfactory epithelium and taste buds as the most likely explanation, with major implications for infectivity, diagnosis and management of the COVID-19 pandemic.

Clinical manifestations and evidence of neurological involvement in 2019 novel coronavirus SARS-CoV-2: a systematic review and meta-analysis

Background

Coronavirus disease 2019 (COVID-19) has become a global pandemic, affecting millions of people. However, clinical research on its neurological manifestations is thus far limited. In this study, we aimed to systematically collect and investigate the clinical manifestations and evidence of neurological involvement in COVID-19.

Methods

Three medical (Medline, Embase, and Scopus) and two preprints (BioRxiv and MedRxiv) databases were systematically searched for all published articles on neurological involvement in COVID-19 since the outbreak. All included studies were systematically reviewed, and selected clinical data were collected for meta-analysis via random-effects.

Results

A total of 41 articles were eligible and included in this review, showing a wide spectrum of neurological manifestations in COVID-19. The meta-analysis for unspecific neurological symptoms revealed that the most common manifestations were fatigue (33.2% [23.1–43.3]), anorexia (30.0% [23.2–36.9]), dyspnea/shortness of breath (26.9% [19.2–34.6]), and malaise (26.7% [13.3–40.1]). The common specific neurological symptoms included olfactory (35.7–85.6%) and gustatory (33.3–88.8%) disorders, especially in mild cases. Guillain–Barré syndrome and acute inflammation of the brain, spinal cord, and meninges were repeatedly reported after COVID-19. Laboratory, electrophysiological, radiological, and pathological evidence supported neurologic involvement of COVID-19.

Conclusions

Neurological manifestations are various and prevalent in COVID-19. Emerging clinical evidence suggests neurological involvement is an important aspect of the disease. The underlying mechanisms can include both direct invasion and maladaptive inflammatory responses. More studies should be conducted to explore the role of neurological manifestations in COVID-19 progression and to verify their underlying mechanisms.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-09974-2) contains supplementary material, which is available to authorized users.

Olfactory Dysfunction in Coronavirus Disease 2019 Patients: Observational Cohort Study and Systematic Review

Background

Olfactory dysfunction (OD) has been reported in coronavirus disease 2019 (COVID-19). However, there are knowledge gaps about the severity, prevalence, etiology, and duration of OD in COVID-19 patients.

Methods

Olfactory function was assessed in all participants using questionnaires and the butanol threshold test (BTT). Patients with COVID-19 and abnormal olfaction were further evaluated using the smell identification test (SIT), sinus imaging, and nasoendoscopy. Selected patients received nasal biopsies. Systematic review was performed according to PRISMA guidelines. PubMed items from January 1, 2020 to April 23, 2020 were searched. Studies that reported clinical data on olfactory disturbances in COVID-19 patients were analyzed.

Results

We included 18 COVID-19 patients and 18 controls. Among COVID-19 patients, 12 of 18 (67%) reported olfactory symptoms and OD was confirmed in 6 patients by BTT and SIT. Olfactory dysfunction was the only symptom in 2 patients. Mean BTT score of patients was worse than controls (P = .004, difference in means = 1.8; 95% confidence interval, 0.6–2.9). Sinusitis and olfactory cleft obstruction were absent in most patients. Immunohistochemical analysis of nasal biopsy revealed the presence of infiltrative CD68⁺ macrophages harboring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen in the stroma. Olfactory dysfunction persisted in 2 patients despite clinical recovery. Systematic review showed that the prevalence of olfactory disturbances in COVID-19 ranged from 5% to 98%. Most studies did not assess olfaction quantitatively.

Conclusions

Olfactory dysfunction is common in COVID-19 and may be the only symptom. Coronavirus disease 2019-related OD can be severe and prolonged. Mucosal infiltration by CD68⁺ macrophages expressing SARS-CoV-2 viral antigen may contribute to COVID-19-related OD.

Olfactory and gustatory dysfunctions in 100 patients hospitalized for COVID-19: sex differences and recovery time in real-life

Purpose

COVID-19 displays a variety of clinical manifestations; in pauci-symptomatic patients olfactory (OD) and gustatory dysfunctions (GD) may represent the first or only symptom. This topic is currently arousing great interest, and a growing number of papers are being published. Aim of this study is to investigate the timing of recovery from OD and GD in a real-life population hospitalized for COVID-19.

Methods

We followed up by a phone interview the first 100 patients discharged a month earlier from three Italian non-intensive care wards.

Results

All 100 patients were Caucasian, mean age was 65 years, 60% were males. Forty-two patients (mean age 63 years) experienced subjective chemosensory dysfunctions (29 OD and 41 GD): the male/female ratio was 2:1; 83% reported a complete or near complete recovery at follow-up. The recovery rate was not significantly different between males and females. The mean duration of OD and GD was 18 and 16 days, respectively. The mean recovery time from OD or GD resulted significantly longer for females than for males (26 vs 14 days, P = 0.009). Among the 42 symptomatic, the mean age of males was significantly higher than that of females (66 vs 57 years, P = 0.04), while the opposite was observed in the 58 asymptomatic patients (60 vs 73 years, P = 0.0018).

Conclusions

Recovery from OD or GD was rapid, occurring within 4 weeks in most patients. Chemosensory dysfunctions in women was less frequent, but longer lasting. The value of our study is its focus on a population of hospitalized patients significantly older than those previously described, and the additional data on gender differences.

Neurological Manifestations of COVID-19 (SARS-CoV-2): A Review

Background: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been associated with many neurological symptoms but there is a little evidence-based published material on the neurological manifestations of COVID-19. The purpose of this article is to review the spectrum of the various neurological manifestations and underlying associated pathophysiology in COVID-19 patients.

Method: We conducted a review of the various case reports and retrospective clinical studies published on the neurological manifestations, associated literature, and related pathophysiology of COVID-19 using PUBMED and subsequent proceedings. A total of 118 articles were thoroughly reviewed in order to highlight the plausible spectrum of neurological manifestations of COVID 19. Every article was either based on descriptive analysis, clinical scenarios, correspondence, and editorials emphasizing the neurological manifestations either directly or indirectly. We then tried to highlight the significant plausible manifestations and complications that could be related to the pandemic. With little known about the dynamics and the presentation spectrum of the virus apart from the respiratory symptoms, this area needs further consideration.

Conclusion: The neurological manifestations associated with COVID-19 such as Encephalitis, Meningitis, acute cerebrovascular disease, and Guillain Barré Syndrome (GBS) are of great concern. But in the presence of life-threatening abnormal vitals in severely ill COVID-19 patients, these are not usually underscored. There is a need to diagnose these manifestations at the earliest to limit long term sequelae. Much research is needed to explore the role of SARS-CoV-2 in causing these neurological manifestations by isolating it either from cerebrospinal fluid or brain tissues of the deceased on autopsy. We also recommend exploring the risk factors that lead to the development of these neurological manifestations.

Aggregate Prevalence of Chemosensory and Sinonasal Dysfunction in SARS-CoV-2 and Related Coronaviruses

Much of the published literature regarding the novel coronavirus disease 2019 (COVID-19) constitutes lower respiratory system symptomatology, while there exists a paucity of data describing the complicated sequelae of the upper respiratory system, including chemosensory and/or sinonasal dysfunction. This study utilized the National Library of Medicine's PubMed/MEDLINE database to query for articles describing COVID-19, SARS-CoV-2, SARS-CoV-1, MERS-CoV, and other coronaviruses, with any mention of smell, taste, or other chemosensory or sinonasal dysfunction. Aggregate analysis demonstrated an incidence of 49.6% (n = 497 of 1002; 95% CI, 46.5%-52.7%), 47.9% (n = 480 of 1002; 95% CI, 44.8%-51.0%), and 17.9% (n = 880 of 4909; 95% CI, 16.9%-19.0%) for smell loss, taste loss, and smell or taste loss, respectively, in patients infected with SARS-CoV-2. Additionally, there were significantly higher incidences of runny nose/rhinorrhea/rhinitis and nasal congestion/obstruction/blockage in other coronaviruses as compared with SARS-CoV-2 (P < .001). Understanding these less well-characterized symptoms may help develop measures for estimating early markers of disease prevalence and/or resolution. Level of evidence: 4.

Cancer is associated with severe disease in COVID-19 patients: a systematic review and meta-analysis

Cancer patients are vulnerable to complications of respiratory viruses. This systematic review and meta-analysis sought to examine the prevalence of cancer and its association with disease severity in patients with novel coronavirus disease 2019 (COVID-19). Searches were performed in MEDLINE, EMBASE and ScienceDirect from their inception until 28 April 2020. Severe disease was considered to encompass cases resulting in death or as defined by the primary study authors. Meta-analysis was performed using random-effect models. We included 20 studies involving 32,404 patients from China, the United Kingdom, the United States, Italy, Singapore, Thailand, France, India and South Korea. The pooled prevalence of cancer was 3.50% (95% confidence interval (CI) 1.70 to 5.80). The pooled prevalence was not moderated by study mean age, proportion of females or whether the study was conducted in/outside of China. Patients with cancer were more likely to experience severe COVID-19 disease compared to patients without cancer (pooled risk ratio 1.76, 95% CI 1.39 to 2.23). Our findings reiterate the need for additional precautionary measures to ensure that patients with cancer are not exposed to COVID-19, and if they become infected, extra attention should be provided to minimise their risk of adverse outcomes.

The Prevalence of Olfactory and Gustatory Dysfunction in COVID-19 Patients: A Systematic Review and Meta-analysis

OBJECTIVE

To determine the pooled global prevalence of olfactory and gustatory dysfunction in patients with the 2019 novel coronavirus (COVID-19).

DATA SOURCES

Literature searches of PubMed, Embase, and Scopus were conducted on April 19, 2020, to include articles written in English that reported the prevalence of olfactory or gustatory dysfunction in COVID-19 patients.

REVIEW METHODS

Search strategies developed for each database contained keywords such as anosmia, dysgeusia, and COVID-19. Resulting articles were imported into a systematic review software and underwent screening. Data from articles that met inclusion criteria were extracted and analyzed. Meta-analysis using pooled prevalence estimates in a random-effects model were calculated.

RESULTS

Ten studies were analyzed for olfactory dysfunction (n = 1627), demonstrating 52.73% (95% CI, 29.64%-75.23%) prevalence among patients with COVID-19. Nine studies were analyzed for gustatory dysfunction (n = 1390), demonstrating 43.93% (95% CI, 20.46%-68.95%) prevalence. Subgroup analyses were conducted for studies evaluating olfactory dysfunction using nonvalidated and validated instruments and demonstrated 36.64% (95% CI, 18.31%-57.24%) and 86.60% (95% CI, 72.95%-95.95%) prevalence, respectively.

CONCLUSIONS

Olfactory and gustatory dysfunction are common symptoms in patients with COVID-19 and may represent early symptoms in the clinical course of infection. Increased awareness of this fact may encourage earlier diagnosis and treatment, as well as heighten vigilance for viral transmission. To our knowledge, this is the first meta-analysis to report on the prevalence of these symptoms in COVID-19 patients.

Therapeutic support protocol for patient with dysosmia with or without dysgeusia related to the SARS-CoV2 virus infection

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[Olfactory dysfunction and COVID-19 - current state of the problem]

According to data from China, Italy, South Korea, Iran, USA, France, from 17 to 87% of patients with confirmed COVID-19 have a violation of smell and taste. Acute sudden anosmia may precede symptoms such as cough and shortness of breath. Also, hypo/anosmia may be the only symptom of mild COVID-19. European, American and domestic associations of otorhinolaryngologists warn that, these patients may be hidden carriers that contribute to the spread of COVID-19 infection, because they have no indications for testing for the virus and self-isolation. Including anosmia in the criteria for self-isolation can help prevent the spread of COVID-19 infection. In addition, it would signal the medical staff to use full personal protection when dealing with these patients and help reduce the number of infected doctors. It is known that olfactory disorders can be conductive, perceptual or mixed. Olfactory disturbances in COVID-19 are most likely of a perceptual nature. Although, at the moment, there is insufficient data to determine the exact mechanisms of the onset of anosmia in patients diagnosed with COVID-19, however, there are studies that confirm these or those theories. The article provides an overview of the data available in the literature on this topic.