Loss of Smell and Taste Among Healthcare Personnel Screened for Coronavirus 2019

Alcohol Sniff Test (AST): An Important Tool for Screening Post-Viral Olfactory Loss in Acute Flu-Like Dysfunction

Olfactory disorders have a significant impact on patients' quality of life but are often underestimated in clinical practice. Upper respiratory tract infections (URTIs) are a common cause of olfactory loss. While most cases of olfactory loss due to URTIs are conductive and reversible, post-viral olfactory dysfunction (PVOD) persists despite symptom improvement. PVOD is attributed to damage to the olfactory epithelium and nerves or central olfactory pathway lesions. The Alcohol Sniff Test (AST) has been proposed as a tool to assess olfactory function in the acute phase and aid in differentiating PVOD from conductive disorders. This study aims to evaluate the effectiveness of the AST as a predictor of post-viral olfactory loss in patients with flu-like syndrome. An observational cross-sectional study was conducted among employees with flu-like syndrome at a tertiary hospital. Three groups were formed: flu-like syndrome with conductive disorder without COVID-19 (PVOD-), flu-like syndrome with neurosensory and/or central disorder due to COVID-19 (PVOD +), and an asymptomatic control group. The Alcohol Sniff Test was performed to assess olfactory function. Statistical analysis was conducted to evaluate the AST's performance. For a cut off of 10 cm, 88.57% of PVOD + patients and 60.53% of PVOD - patients showed AST alteration, respectively (p = 0.013, OR = 5.05, 95% CI [1.48-17.25]). There was a statistically significant difference in the mean distance between the PVOD + group (4.35 ± 4.1 cm) and the control group (20 ± 4.33 cm) (p < 0.05). This relationship was also observed between the PVOD + and PVOD- groups (9 cm ± 7.5) (p < 0.05) and between the PVOD- and control groups (p < 0.05). For a cut off of 10 cm, the AST showed a sensitivity of 88% and specificity of 41%, resulting in an Odds Ratio of 9.7 (95% CI 3.3-28.1) (p < 0.001) and a Positive Predictive Value of 69.4% for PVOD. PVOD, including cases associated with COVID-19, is a prevalent cause of olfactory loss. The Alcohol Sniff Test demonstrated promising results in identifying PVOD in patients with flu-like syndrome. The test's simplicity and accessibility make it a valuable tool for early screening and identifying individuals who may benefit from prompt treatment. The Alcohol Sniff Test (AST) shows potential as an effective tool for screening post-viral olfactory loss in patients with flu-like syndrome. It can aid in early identification of PVOD cases and facilitate timely interventions to reduce the likelihood of persistent hyposmia.

Olfactory and gustatory dysfunction, evaluation and the impact on quality of life among COVID-19 patients: a multi-centre study

Background

Olfactory and gustatory dysfunctions are frequently reported symptoms among COVID-19 patients. However, several reports suggested that there might be significant variation in the prevalence and clinical picture of chemosensory dysfunction in COVID-19 patients among different population.

Objective

To study the prevalence of chemosensory dysfunction, recovery time and its impact on quality of life (QoL) among COVID-19 patients in Saudi population.

Methods

This multi-centre observational study was conducted at three COVID-19 centres in Saudi Arabia. Epidemiological and clinical data were extracted at baseline and within the 2-month post-infection. Olfactory and gustatory dysfunctions were assessed via valid taste and smell questionnaire, electronically collected via online survey. Short version of questionnaire of Olfactory disorders-negative statements (sQOD-NS) was used to assess the impact on QoL.

Result

Total 1734 patients [926 males and 808 females, the mean age of patients was 37.7±11.6 years] with laboratory confirmed COVID-19 were recruited for this study. Chemosensory dysfunction was reported in 56.5% cases. olfactory and gustatory dysfunctions were significantly high in females (66.2%) and age group younger than or equal to 40 years (62.2%). Among patients with olfactory dysfunction and gustatory dysfunction, recovery rate was 757 (77.2%) and 702 (71.6%). Furthermore, the recovery time was within 8 days of onset of symptoms in 53.6% and 61.3% of olfactory dysfunction and gustatory dysfunction cases, respectively. Overall mean QoL score indicated Olfactory and gustatory dysfunction has significant impact on QoL [11.3±6.2 (P value<0.001)]. female as compared to males (12.8±7). Females had significant impact on QoL (11.4±6.6) as compared to males [12.8±7 (P value<0.001)].

Conclusion

Chemosensory dysfunction among Saudi population was comparable to the European data and significantly higher than Asian supporting the fact that these symptoms vary as per ethnicity. Olfactory and gustatory dysfunction significantly impaired QoL and could present as an early symptom of COVID-19. Recovery rate of these symptoms can serve as a good prognostic data for patient's counselling. Further long-term follow-up studies would lead to better understanding of prognosis and clinical outcomes.

In vitro and Intracellular Antibacterial Activity of Sudapyridine (WX-081) Against Tuberculosis

Background

Sudapyridine (WX-081) has exhibited equivalent efficacy than its counterpart parent drug bedaquiline (BDQ) but better safety profile against Mycobacterium tuberculosis (Mtb). Our study was aimed to evaluate in vitro activity of WX-081 against the clinical isolates of Mtb with different drug-resistance profiles and the intracellular bactericidal activity against the reference strain.

Methods

The minimum inhibitory concentrations (MICs) of WX-081 and BDQ were tested against 114 Mtb clinical isolates. The intracellular activity of WX-081 and BDQ against the Mtb reference strain H37Rv in THP-1 cells was also evaluated in parallel.

Results

The MICs for WX-081 of the enrolled isolates ranged from 0.0156 μg/mL to 1 μg/mL. The MIC₅₀ and MIC₉₀ of WX-081 were, respectively, 0.25 μg/mL and 0.5 μg/mL, with 95.6% of the enrolled strains having MICs ≤0.25 μg/mL. For a given strain, the MIC value of WX-081 was generally equivalent to or 2-fold than MIC of BDQ. The intracellular bacterial killing was acquired with the tested drug concentrations that were presumed attainable during clinical usage.

Conclusion

WX-081 exhibited potent efficacy against the clinical isolates in vitro. The intracellular killing effect of sudapyridine against the reference strain supports its potential efficacy in treating TB patients.

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.

Pharmacokinetics of Antituberculosis Drugs in Plasma and Cerebrospinal Fluid in a Patient with Pre-Extensive Drug Resistant Tuberculosis Meningitis

Drug-resistant tuberculous meningitis (TBM) is the most devastating and critical form of extrapulmonary tuberculosis. Here, we present a case of a 45-year-old male with pre-extensive drug-resistant tuberculosis meningitis (pre-XDR-TBM). He underwent emergency surgery for the long-tunneled external ventricular drainage (LTEVD). Molecular test and phenotypic drug sensitivity test (DST) of Mycobacterium tuberculosis in cerebrospinal fluid (CSF) showed that the isolate was resistant to both rifampin and fluoroquinolones. An anti-tuberculous regimen of isoniazid, pyrazinamide, cycloserine, moxifloxacin, clofazimine, and linezolid was tailored accordingly. We monitored the drug concentration in his plasma and CSF before (at 0-hour) and after anti-TB drugs administration (at 1-hour, 2-hour, 6-hour, and 12-hour) on 10^th day after treatment initiation. We hope to provide reference values of drug exposures in plasma and CSF for patients with pre-XDR-TBM.

Bilateral papilledema with vision loss due to post-COVID-19-induced thiamine deficiency: illustrative case

BACKGROUND

Bilateral papilledema with vision loss is considered a neurosurgical emergency due to high intracranial pressure. However, it may not be the only cause of papilledema. The authors reported an association among coronavirus disease 2019 (COVID-19), bilateral papilledema, blindness, and Wernicke's encephalopathy (WE).

OBSERVATIONS

An 18-year-old woman presented to the neurosurgery service with rapid profound vision loss and bilateral papilledema. She had COVID-19 3 months earlier with subsequent loss of smell (anosmia) and taste (ageusia), which resulted in hyperemesis and a 43-lb weight loss. Examination revealed ataxia, horizontal nystagmus, and blindness. Magnetic resonance imaging and magnetic resonance venography of her brain were normal. Presumptive diagnosis of WE was made, and she was treated with intravenous thiamine with restoration of vision within 48 hours. Patient's thiamine level was less than half the normal value.

LESSONS

Neurosurgeons should be aware of this unique correlation between papilledema and vision loss and its association with WE due to post-COVID-19 hyperemesis and weight loss from anosmia and ageusia.

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.

Signs and symptoms to determine if a patient presenting in primary care or hospital outpatient settings has COVID-19

BACKGROUND

COVID-19 illness is highly variable, ranging from infection with no symptoms through to pneumonia and life-threatening consequences. Symptoms such as fever, cough, or loss of sense of smell (anosmia) or taste (ageusia), can help flag early on if the disease is present. Such information could be used either to rule out COVID-19 disease, or to identify people who need to go for COVID-19 diagnostic tests. This is the second update of this review, which was first published in 2020.

OBJECTIVES

To assess the diagnostic accuracy of signs and symptoms to determine if a person presenting in primary care or to hospital outpatient settings, such as the emergency department or dedicated COVID-19 clinics, has COVID-19.

SEARCH METHODS

We undertook electronic searches up to 10 June 2021 in the University of Bern living search database. In addition, we checked repositories of COVID-19 publications. We used artificial intelligence text analysis to conduct an initial classification of documents. We did not apply any language restrictions.

SELECTION CRITERIA

Studies were eligible if they included people with clinically suspected COVID-19, or recruited known cases with COVID-19 and also controls without COVID-19 from a single-gate cohort. Studies were eligible when they recruited people presenting to primary care or hospital outpatient settings. Studies that included people who contracted SARS-CoV-2 infection while admitted to hospital were not eligible. The minimum eligible sample size of studies was 10 participants. All signs and symptoms were eligible for this review, including individual signs and symptoms or combinations. We accepted a range of reference standards.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected all studies, at both title and abstract, and full-text stage. They resolved any disagreements by discussion with a third review author. Two review authors independently extracted data and assessed risk of bias using the QUADAS-2 checklist, and resolved disagreements by discussion with a third review author. Analyses were restricted to prospective studies only. We presented sensitivity and specificity in paired forest plots, in receiver operating characteristic (ROC) space and in dumbbell plots. We estimated summary parameters using a bivariate random-effects meta-analysis whenever five or more primary prospective studies were available, and whenever heterogeneity across studies was deemed acceptable.

MAIN RESULTS

We identified 90 studies; for this update we focused on the results of 42 prospective studies with 52,608 participants. Prevalence of COVID-19 disease varied from 3.7% to 60.6% with a median of 27.4%. Thirty-five studies were set in emergency departments or outpatient test centres (46,878 participants), three in primary care settings (1230 participants), two in a mixed population of in- and outpatients in a paediatric hospital setting (493 participants), and two overlapping studies in nursing homes (4007 participants). The studies did not clearly distinguish mild COVID-19 disease from COVID-19 pneumonia, so we present the results for both conditions together. Twelve studies had a high risk of bias for selection of participants because they used a high level of preselection to decide whether reverse transcription polymerase chain reaction (RT-PCR) testing was needed, or because they enrolled a non-consecutive sample, or because they excluded individuals while they were part of the study base. We rated 36 of the 42 studies as high risk of bias for the index tests because there was little or no detail on how, by whom and when, the symptoms were measured. For most studies, eligibility for testing was dependent on the local case definition and testing criteria that were in effect at the time of the study, meaning most people who were included in studies had already been referred to health services based on the symptoms that we are evaluating in this review. The applicability of the results of this review iteration improved in comparison with the previous reviews. This version has more studies of people presenting to ambulatory settings, which is where the majority of assessments for COVID-19 take place. Only three studies presented any data on children separately, and only one focused specifically on older adults. We found data on 96 symptoms or combinations of signs and symptoms. Evidence on individual signs as diagnostic tests was rarely reported, so this review reports mainly on the diagnostic value of symptoms. Results were highly variable across studies. Most had very low sensitivity and high specificity. RT-PCR was the most often used reference standard (40/42 studies). Only cough (11 studies) had a summary sensitivity above 50% (62.4%, 95% CI 50.6% to 72.9%)); its specificity was low (45.4%, 95% CI 33.5% to 57.9%)). Presence of fever had a sensitivity of 37.6% (95% CI 23.4% to 54.3%) and a specificity of 75.2% (95% CI 56.3% to 87.8%). The summary positive likelihood ratio of cough was 1.14 (95% CI 1.04 to 1.25) and that of fever 1.52 (95% CI 1.10 to 2.10). Sore throat had a summary positive likelihood ratio of 0.814 (95% CI 0.714 to 0.929), which means that its presence increases the probability of having an infectious disease other than COVID-19. Dyspnoea (12 studies) and fatigue (8 studies) had a sensitivity of 23.3% (95% CI 16.4% to 31.9%) and 40.2% (95% CI 19.4% to 65.1%) respectively. Their specificity was 75.7% (95% CI 65.2% to 83.9%) and 73.6% (95% CI 48.4% to 89.3%). The summary positive likelihood ratio of dyspnoea was 0.96 (95% CI 0.83 to 1.11) and that of fatigue 1.52 (95% CI 1.21 to 1.91), which means that the presence of fatigue slightly increases the probability of having COVID-19. Anosmia alone (7 studies), ageusia alone (5 studies), and anosmia or ageusia (6 studies) had summary sensitivities below 50% but summary specificities over 90%. Anosmia had a summary sensitivity of 26.4% (95% CI 13.8% to 44.6%) and a specificity of 94.2% (95% CI 90.6% to 96.5%). Ageusia had a summary sensitivity of 23.2% (95% CI 10.6% to 43.3%) and a specificity of 92.6% (95% CI 83.1% to 97.0%). Anosmia or ageusia had a summary sensitivity of 39.2% (95% CI 26.5% to 53.6%) and a specificity of 92.1% (95% CI 84.5% to 96.2%). The summary positive likelihood ratios of anosmia alone and anosmia or ageusia were 4.55 (95% CI 3.46 to 5.97) and 4.99 (95% CI 3.22 to 7.75) respectively, which is just below our arbitrary definition of a 'red flag', that is, a positive likelihood ratio of at least 5. The summary positive likelihood ratio of ageusia alone was 3.14 (95% CI 1.79 to 5.51). Twenty-four studies assessed combinations of different signs and symptoms, mostly combining olfactory symptoms. By combining symptoms with other information such as contact or travel history, age, gender, and a local recent case detection rate, some multivariable prediction scores reached a sensitivity as high as 90%.

AUTHORS' CONCLUSIONS

Most individual symptoms included in this review have poor diagnostic accuracy. Neither absence nor presence of symptoms are accurate enough to rule in or rule out the disease. The presence of anosmia or ageusia may be useful as a red flag for the presence of COVID-19. The presence of cough also supports further testing. There is currently no evidence to support further testing with PCR in any individuals presenting only with upper respiratory symptoms such as sore throat, coryza or rhinorrhoea. Combinations of symptoms with other readily available information such as contact or travel history, or the local recent case detection rate may prove more useful and should be further investigated in an unselected population presenting to primary care or hospital outpatient settings. The diagnostic accuracy of symptoms for COVID-19 is moderate to low and any testing strategy using symptoms as selection mechanism will result in both large numbers of missed cases and large numbers of people requiring testing. Which one of these is minimised, is determined by the goal of COVID-19 testing strategies, that is, controlling the epidemic by isolating every possible case versus identifying those with clinically important disease so that they can be monitored or treated to optimise their prognosis. The former will require a testing strategy that uses very few symptoms as entry criterion for testing, the latter could focus on more specific symptoms such as fever and anosmia.

Long-Lasting Olfactory Dysfunction in Hospital Workers Due to COVID-19: Prevalence, Clinical Characteristics, and Most Affected Odorants

Hospital workers have increased exposure risk of healthcare-associated infections due to the frontline nature of their work. Olfactory dysfunction is highly prevalent. The objectives for this investigation are to study the prevalence of long-lasting olfactory dysfunction associated with COVID-19 infection in hospital workers during the first pandemic wave, to identify clinical characteristics and associated symptomatology, and to analyze how many patients with COVID-19 infection had developed olfactory dysfunction during infection and maintained a reduced olfactory function for approximately 10 weeks after diagnosis. Between June and July of 2020, a cross-sectional study was carried out at the Hospital Central de la Cruz Roja San José and Santa Adela in Madrid, Spain. One hundred sixty-four participants were included, of which 110 were patient-facing healthcare staff and 54 were non-patient-facing healthcare staff. Participants were split into three groups, according to COVID-19 diagnosis and presence of COVID-19 related olfactory symptomatology. Participants were asked to complete a structured online questionnaire along with Sniffin' Stick Olfactory Test measurements. In this study, 88 participants were confirmed for COVID-19 infection, 59 of those participants also reported olfactory symptomatology. The prevalence of COVID-19 infection was 11.35%, and the prevalence for olfactory dysfunction was 67.05%. Olfactory dysfunction associated with COVID-19 infection leads to long-lasting olfactory loss. Objective assessment with Sniffin' Stick Olfactory Test points to odor identification as the most affected process. Lemon, liquorice, solvent, and rose are the odors that are worst recognized. Mint, banana, solvent, garlic, coffee, and pineapple, although they are identified, are perceived with less intensity. The findings of this study confirmed a high prevalence of SARS-CoV-2 infection among the hospital workers.

Long‐term prevalence of taste and olfactory dysfunction in COVID‐19 patients: A cross‐sectional study

Objectives

The objectives of the study were to investigate the long‐term prevalence of taste disorder (TD) and olfactory disorder (OD) and associated risk factors in the non‐hospitalized southeastern Brazil population of COVID‐19 patients.

Methods

This cross‐sectional open survey evaluated possible long‐term OD and TD in non‐hospitalized patients who had been diagnosed with COVID‐19 for more than 30 days, through an online self‐report questionnaire. Demographic data, comorbidities, symptoms, and the intensity of OD and TD at the time of diagnosis and at the time of completing the questionnaire were evaluated.

Results

Three hundred five responses were included. The reported prevalence of OD and TD was 72.9% and 67.4%, respectively, in the moment of diagnosis; after a mean follow‐up period of 179 days, 45% and 50% still had some degree of the symptoms. There was a positive correlation between age and the high prevalence of OD (p = 0.02). However, there was no correlation between age and TD (p = 0.961) and weight in relation to OD/TD (p = 0.500 and p = 0.636, respectively).

Conclusion

This study observed a high long‐term prevalence of OD and TD associated with COVID‐19, with a low recovery rate during the study period. There was a positive association between older participants and the prevalence of OD.

SARS-CoV-2 seroprevalence among healthcare personnel at a large health system in Atlanta

Background

Estimates of the prevalence of SARS-CoV-2 antibodies and factors associated with infection among healthcare personnel (HCP) vary widely. We conducted a serosurvey of HCP at a large public healthcare system in the Atlanta area.

Materials and methods

All employees of Grady Health System were invited to participate in mid-2020; a volunteer sample of those completing testing was included. Asymptomatic HCP were offered testing for IgG antibody and for SARS-CoV-2 RNA using polymerase chain reaction (PCR). Symptomatic HCP were offered PCR testing. Antibody index values for IgG and cycle threshold values for PCR were evaluated for those with a positive result. An online survey was distributed at the time of testing.

Results

624 of 1677 distributed surveys (37.2%) were completed by 608 unique HCP. The majority were female (76.4%) and provided clinical care (70.9%). The most common occupations were clinician (24.8%) and nurse (23.5%). 37 of 608 (6.1%) HCP had detectable IgG. Exposure to a confirmed case of COVID-19 outside of the hospital was associated with detectable IgG (12.8% vs 4.4%, p = 0.02), but exposure to a patient with COVID-19 was not.

Conclusions

Among HCP in a large healthcare system, 6.1% had detectable SARS-CoV-2 IgG. Seropositivity was associated with exposures outside of the healthcare setting.

Differential COVID-19 Symptoms Given Pandemic Locations, Time, and Comorbidities During the Early Pandemic

BACKGROUND

COVID-19 pandemic is disaster to public health worldwide. Better perspective on COVID's features early in its course-prior to the development of vaccines and widespread variants-may prove useful in the understanding of future pandemics. Ontology provides a standardized integrative method for knowledge modeling and computer-assisted reasoning. In this study, we systematically extracted and analyzed clinical phenotypes and comorbidities in COVID-19 patients found at different countries and regions during the early pandemic using an ontology-based bioinformatics approach, with the aim to identify new insights and hidden patterns of the COVID-19 symptoms.

RESULTS

A total of 48 research articles reporting analysis of first-hand clinical data from over 40,000 COVID-19 patients were surveyed. The patients studied therein were diagnosed with COVID-19 before May 2020. A total of 18 commonly-occurring phenotypes in these COVID-19 patients were first identified and then classified into different hierarchical groups based on the Human Phenotype Ontology (HPO). This meta-analytic approach revealed that fever, cough, and the loss of smell and taste were ranked as the most commonly-occurring phenotype in China, the US, and Italy, respectively. We also found that the patients from Europe and the US appeared to have more frequent occurrence of many nervous and abdominal symptom phenotypes (e.g., loss of smell, loss of taste, and diarrhea) than patients from China during the early pandemic. A total of 22 comorbidities, such as diabetes and kidney failure, were found to commonly exist in COVID-19 patients and positively correlated with the severity of the disease. The knowledge learned from the study was further modeled and represented in the Coronavirus Infectious Disease Ontology (CIDO), supporting semantic queries and analysis. Furthermore, also considering the symptoms caused by new viral variants at the later stages, a spiral model hypothesis was proposed to address the changes of specific symptoms during different stages of the pandemic.

CONCLUSIONS

Differential patterns of symptoms in COVID-19 patients were found given different locations, time, and comorbidity types during the early pandemic. The ontology-based informatics provides a unique approach to systematically model, represent, and analyze COVID-19 symptoms, comorbidities, and the factors that influence the disease outcomes.

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.

Exploring the Clinical Utility of Gustatory Dysfunction (GD) as a Triage Symptom Prior to Reverse Transcription Polymerase Chain Reaction (RT-PCR) in the Diagnosis of COVID-19: A Meta-Analysis and Systematic Review

BACKGROUND

The diagnosis of COVID-19 is made using reverse transcription polymerase chain reaction (RT-PCR) but its sensitivity varies from 20 to 100%. The presence of gustatory dysfunction (GD) in a patient with upper respiratory tract symptoms might increase the clinical suspicion of COVID-19.

AIMS

To perform a systematic review and meta-analysis to determine the pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and diagnostic odds ratio (DOR) of using GD as a triage symptom prior to RT-PCR.

METHODS

PubMed and Embase were searched up to 20 June 2021. Studies published in English were included if they compared the frequency of GD in COVID-19 adult patients (proven by RT-PCR) to COVID-19 negative controls in case control or cross-sectional studies. The Newcastle-Ottawa scale was used to assess the methodological quality of the included studies.

RESULTS

21,272 COVID-19 patients and 52,298 COVID-19 negative patients were included across 44 studies from 21 countries. All studies were of moderate to high risk of bias. Patients with GD were more likely to test positive for COVID-19: DOR 6.39 (4.86-8.40), LR+ 3.84 (3.04-4.84), LR- 0.67 (0.64-0.70), pooled sensitivity 0.37 (0.29-0.47) and pooled specificity 0.92 (0.89-0.94). While history/questionnaire-based assessments were predictive of RT-PCR positivity (DOR 6.62 (4.95-8.85)), gustatory testing was not (DOR 3.53 (0.98-12.7)). There was significant heterogeneity among the 44 studies (I2 = 92%, p < 0.01).

CONCLUSIONS

GD is useful as a symptom to determine if a patient should undergo further testing, especially in resource-poor regions where COVID-19 testing is scarce. Patients with GD may be advised to quarantine while repeated testing is performed if the initial RT-PCR is negative.

FUNDING

None.

Self-reported olfactory and gustatory dysfunction and psychophysical testing in screening for Covid-19: A systematic review and meta-analysis

Background

A substantial proportion of coronavirus disease‐2019 (COVID‐19) patients demonstrate olfactory and gustatory dysfunction (OGD). Self‐reporting for OGD is widely used as a predictor of COVID‐19. Although psychophysical assessment is currently under investigation in this role, the sensitivity of these screening tests for COVID‐19 remains unclear. In this systematic review we assess the sensitivity of self‐reporting and psychophysical tests for OGD.

Methods

A systematic search was performed on PubMed, EMBASE, and ClinicalTrials.gov from inception until February 16, 2021. Studies of suspected COVID‐19 patients with reported smell or taste alterations were included. Data were pooled for meta‐analysis. Sensitivity, specificity, and diagnostic odds ratio (DOR) were reported in the outcomes.

Results

In the 50 included studies (42,902 patients), self‐reported olfactory dysfunction showed a sensitivity of 43.9% (95% confidence interval [CI], 37.8%‐50.2%), a specificity of 91.8% (95% CI, 89.0%‐93.9%), and a DOR of 8.74 (95% CI, 6.67‐11.46) for predicting COVID‐19 infection. Self‐reported gustatory dysfunction yielded a sensitivity of 44.9% (95% CI, 36.4%‐53.8%), a specificity of 91.5% (95% CI, 87.7%‐94.3%), and a DOR of 8.83 (95% CI, 6.48‐12.01). Olfactory psychophysical tests analysis revealed a sensitivity of 52.8% (95% CI, 25.5%‐78.6%), a specificity of 88.0% (95% CI, 53.7%‐97.9%), and a DOR of 8.18 (95% CI, 3.65‐18.36). One study used an identification test for gustatory sensations assessment.

Conclusion

Although demonstrating high specificity and DOR values, neither self‐reported OGD nor unvalidated and limited psychophysical tests were sufficiently sensitive in screening for COVID‐19. They were not suitable adjuncts in ruling out the disease.

Systematic review of productivity loss among healthcare workers due to Covid-19

Objective

To assess existing evidence on the effects of COVID‐19 on healthcare workers (HCWs) using the health‐related productivity loss approach.

Methods

A systematic search of online databases including PubMed, Scopus, Ovid, Web of Science, and EMBASE was conducted up to 25 August 2020. Following two screening stages, studies related to the effects of COVID‐19 on healthcare workers were included in the study.

Results

82 studies were included in the analysis. The COVID‐19 related death rate among HCWs ranged from 0.00‐0.7%, while the positive test incidence varied between 0.00 and 24.4%. 39 evidences assessed psychological disorders. A wide range of psychological disorders observed among HCWs: 5.2 to 71.2% in anxiety, 1.00 to 88.3% in stress, 8.27 to 61.67% in insomnia, and 4.5 to 50.4% in depression.

Conclusions

The early evidence suggests that healthcare workers are one of the most vulnerable groups when it comes to positive COVID‐19 infection, mortality, and mental illness.

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.

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.

Seroprevalence of SARS-CoV-2 antibody among healthcare workers in a university hospital in Mallorca, Spain, during the first wave of the COVID-19 pandemic

OBJECTIVE

To estimate the SARS-CoV-2 antibody seroprevalence in healthcare workers (HCWs) at a university hospital in Mallorca, Spain.

METHODS

All HCWs received an e-mail inviting them to take part in the study. Participants had a nasopharyngeal swab test performed for reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and serological tests to detect SARS-CoV-2 antibodies (primary study). Additionally, they were invited to complete a questionnaire on their exposure to COVID-19 individuals and their COVID-19-related symptoms (secondary study). Prevalence of antibodies (IgG, IgM, or both) and 95% confidence intervals (CIs) were calculated.

RESULTS

Seventy-nine percent of the hospital's HCWs (N = 2210) took part in the primary study. Antibodies were detected in 61 participants, a prevalence of 2.8% (95% CI: 2.5-3.1). The prevalence was slightly higher in nurses (3.4%), registrars (3.9%), and wardens (3.4%). Thirty-nine percent of the primary study participants completed the secondary study questionnaire. Those with positive antibody test results had closer contact with COVID-19 individuals (60% vs. 92%; p < 0.001).

CONCLUSION

After the first wave of the COVID-19 pandemic in Spain, the seroprevalence of SARS-CoV-2 antibodies in our university hospital HCWs was around 2.8%, which is slightly higher than the seroprevalence in the general population in our region. We believe it would be advisable to perform additional seroprevalence studies during the second wave of the epidemic.

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.

The Association of "Loss of Smell" to COVID-19: A Systematic Review and Meta-Analysis

BACKGROUND

The presence of olfactory dysfunction or "loss of smell" has been reported as an atypical symptom in patients with coronavirus disease 2019 (COVID-19). We performed a systematic review and meta-analysis of the available literature to evaluate the prevalence of "loss of smell" in COVID-19 as well as its utility for prognosticating the disease severity.

METHODS

An exhaustive search of the PubMed/Medline, Embase, Web of Science, Cochrane Library, LitCovid NIH, and WHO COVID-19 database was conducted through August 6th, 2020. All studies reporting the prevalence of "loss of smell" (anosmia and/or hyposmia/microsmia) in laboratory-confirmed COVID-19 patients were included. Pooled prevalence for cases (positive COVID-19 through reverse transcriptase (RT-PCR) and/or serology IgG/IgM) and controls (negative RT-PCR and/or serology) was compared, and the odds ratio (OR), 95% confidence interval (CI) and the p-value were calculated. A p-value of <0.05 was considered statistically significant.

RESULTS

A total of 51 studies with 11074 confirmed COVID-19 patients were included. Of these, 21 studies used a control group with 3425 patients. The symptom of "loss of smell" (OR: 14.7, CI: 8.9-24.3) was significantly higher in the COVID-19 group when compared to the control group. Seven studies comparing severe COVID-19 patients with- and without "loss of smell" demonstrated favorable prognosis for patients with "loss of smell" (OR: 0.36, CI 0.27-0.48).

CONCLUSIONS

Olfactory dysfunction or "loss of smell" is a prevalent symptom in COVID-19 patients. Moreover, COVID-19 patients with "loss of smell" appear to have a milder course of the disease.

Chemosensory Dysfunction in Patients with COVID-19: What Do We Learn from the Global Outbreak?

PURPOSE OF REVIEW

Chemosensory dysfunction in the patients with COVID-19 has been reported frequently in the studies from different regions of the world. However, the prevalence of smell and/or taste disorders presents significant ethnic and geographic variability. In addition, the pathogenesis of chemosensory dysfunction remains unclarified.

RECENT FINDINGS

This is a narrative review on the recent state of the prevalence, mechanism, and diagnostic and therapeutic strategy of chemosensory dysfunction in COVID-19 patients during the global pandemic. The chemosensory dysfunction was analysis based on recent studies, which either used questionnaires, Likert scales (0-10), or smell tests to estimate the smell and taste dysfunction. The ethnic and geographic difference of the prevalence of smell and/or taste disorders and the potential underlying mechanisms have been discussed. Several suggestions on the diagnosis and treatment of COVID-19 patients with smell and taste disorders were summarized for the physicians. This review provides a comprehensive overview of the current studies regarding the chemosensory dysfunction during the COVID-19 worldwide outbreak.

Olfactory and taste dysfunction among mild-to-moderate symptomatic COVID-19 positive health care workers: An international survey

OBJECTIVES

To determine the prevalence of olfactory and taste dysfunction (OD; TD) among COVID-19 positive health care workers (HCWs), their associated risk factors and prognosis.

METHODS

Between May and June 2020, a longitudinal multicenter study was conducted on symptomatic COVID-19 PCR confirmed HCWs (COVID-19 positive) in London and Padua.

RESULTS

Hundred and fourteen COVID-19 positive HCWs were surveyed with a response rate of 70.6% over a median follow-up period of 52 days. UK prevalence of OD and TD was 73.1% and 69.2%, respectively. There was a male to female ratio of 1:3 with 81.6% being white, 43.7% being nurses/health care assistants (HCAs), and 39.3% being doctors. In addition, 53.2% of them worked on COVID-19 wards. Complete recovery was reported in 31.8% for OD and 47.1% for TD with a 52 days follow-up. The job role of doctors and nurses negatively influenced smell (P = .04 and P = .02) and taste recovery (P = .02 and P = .01). Ethnicity (being white) showed to positively influence only taste recovery (P = .04). Sex (being female) negatively influenced OD and TD recovery only in Paduan HCWs (P = .02 and P = .011, respectively). Working on a COVID-19 ward did not influence prognosis.

CONCLUSIONS

The prevalence of OD and TD was considerably higher in HCWs. The prognosis for OD and TD recovery was worse for nurses/HCAs and doctors but working on a COVID-19 ward did not influence prognosis. Sixty-eight percent of surveyed HCWs at 52 days continued to experience OD or TD requiring additional future medical management capacity.

LEVEL OF EVIDENCE

4.

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

A significant proportion of people who test positive for COVID-19 have chemosensory deficits. However, the reported prevalence of these deficits in smell and 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 and meta-analysis. We searched the COVID-19 portfolio of the National Institutes of Health for studies that reported the prevalence of smell or taste deficits or both in patients diagnosed with COVID-19. One-hundred-four studies reporting on 38 198 patients qualified and were subjected to a systematic review and meta-analysis. Estimated random prevalence of olfactory dysfunction was 43.0%, that of taste dysfunction was 44.6%, and that of overall chemosensory dysfunction was 47.4%. We examined the effects of age, gender, disease severity, and ethnicity on chemosensory dysfunction. Prevalence of smell or taste dysfunction or both decreased with older age, male gender, and disease severity. Ethnicity was highly significant: Caucasians had a three times higher prevalence of chemosensory dysfunctions (54.8%) than Asians (17.7%). The finding of geographic differences points to two causes that are not mutually exclusive. A virus mutation (D614G) may cause differing infectivity, while at the host level genetic, ethnicity-specific variants of the virus-binding entry proteins may facilitate virus entry in the olfactory epithelium and taste buds. Both explanations have major implications for infectivity, diagnosis, and management of the COVID-19 pandemic.