Olfactory and taste disorders in COVID-19: a systematic review / Desordens olfativas e gustativas na COVID-19: uma revisão sistemática

Abstract Introduction: The SARS-CoV-2 virus causes COVID-19, and it is responsible for the largest pandemic since the 1918 H1N1 influenza outbreak. The classic symptoms of the disease have been well defined by the World Health Organization; however, olfactory/gustatory disorders have been reported in some studies, but there are still several missing points in the understanding and in the consensus about the clinical management of these cases. Objective: To identify evidence in the scientific literature about olfactory/gustatory disorders, their clinical presentation, prevalence and possible specific treatments associated with COVID-19. Methods: A systematic review of articles published up to April 25, 2020 was performed in Medline, Cochrane Clinical Trials, ScienceDirect, Lilacs, Scopus and Google Schoolar, OpenGrey.eu, DissOnline, The New York Academy of Medicine and Reasearch Gate. Inclusion criteria: (1) Studies on patients with COVID-19; (2) Records of COVID-19 signs/symptoms, and olfactory/gustatory functions. Exclusion criteria: (1) Studies on non-human coronavirus; (2) Review articles; (3) Experimental studies (in animals or in vitro); (4) Olfactory/gustatory disorders initiated prior to SARS-CoV-2 infection. The risk assessment of bias of the selected studies was performed using the Newcastle-Ottawa scale. Results: Six articles from the 1788 records met the inclusion criteria and were analyzed. A total of 1457 patients of different ethnicities were assessed; of them, 885 (60.7%) and 822 (56.4%) had smell and taste disorders, respectively, with women being most often affected. There were olfactory/gustatory disorders even without nasal obstruction/rhinorrhea and beginning even before the signs/symptoms of COVID-19; the recovery of smell/taste, when it occurs, usually happened in the first two weeks after COVID-19 resolution. There is evidence that olfactory/gustatory disorders are strong predictors of infection by SARS-CoV-2, and it is possible to recommend patient isolation, as early as of the medical consultation, preventing the spread of the virus. No scientific evidence has been identified for effective treatments for any of the disorders. Conclusion: Olfactory/gustatory disorders may occur at varying intensities and prior to the general symptoms of COVID-19 and should be considered as part of the clinical features of COVID-19, even in mild cases. There is still no scientific evidence of specific treatments for such disorders in COVID-19 disease.

Resumo Introdução: O vírus SARS-CoV-2 causa a COVID-19 e é responsável pela maior pandemia desde o surto de influenza H1N1 de 1918. Os sintomas clássicos da doença já foram bem definidos pela Organização Mundial da Saúde; entretanto, distúrbios olfativo-gustativos têm sido relatados em alguns estudos, mas ainda com várias lacunas no entendimento e no consenso sobre a condução clínica desses casos. Objetivo: Identificar evidências na literatura científica sobre os distúrbios olfativo-gustativos acerca da apresentação clínica, prevalência e possíveis tratamentos específicos associados à COVID-19. Método: Revisão sistemática de artigos publicados até 25 de abril de 2020 nas bases de dados: Medline, Cochrane Clinical Trials, ScienceDirect, Lilacs, Scopus e Google Schoolar, OpenGrey.eu, DissOnline, The New York Academy of Medicine e Research Gate. Foram critérios de inclusão: 1) Estudos com indivíduos com COVID-19; 2) Registro dos sinais/sintomas da COVID-19 e das funções olfativo-gustativa. Foram critérios de exclusão: 1) Estudos sobre coronavírus não humano; 2) Artigos de revisão; 3) Estudos experimentais (em animais ou in vitro); 4) Distúrbios olfativos-gustativos iniciados previamente à infecção pelo SARS-CoV-2. A avaliação de risco de viés dos estudos selecionados foi feita por meio da escala de Newcastle-Ottawa. Resultados: Seis artigos dos 1.788 registros foram selecionados. Um total de 1.457 pacientes de diversas etnias foi avaliado; desses, 885 (60,7%) apresentaram perda do olfato e 822 (56,4%) perda do paladar, sendo as mulheres as mais afetadas. Os distúrbios olfativo-gustativos estiveram presentes mesmo sem obstrução nasal/rinorreia e com início mesmo antes dos sinais/sintomas clínicos da COVID-19; a recuperação do olfato/paladar, quando ocorre, geralmente se dá nas duas primeiras semanas após a resolução da doença. Há evidências de que os distúrbios olfativo-gustativos sejam fortes preditores de infecção pelo SARS-CoV-2, podendo-se recomendar o isolamento do paciente, já a partir da consulta médica, para evitar a disseminação do vírus. Não foram identificadas evidências científicas para tratamentos eficazes para qualquer dos distúrbios. Conclusão: Podem ocorrer distúrbios olfativo-gustativos em intensidades variáveis e prévios aos sintomas gerais da COVID-19, devem ser considerados como parte dos sintomas da doença, mesmo em quadros leves. Não há ainda evidências científicas de tratamentos específicos para tais distúrbios na COVID-19.

Olfactory and taste disorders in COVID-19: a systematic review.

INTRODUCTION: The SARS-CoV-2 virus causes COVID-19, and it is responsible for the largest pandemic since the 1918 H1N1 influenza outbreak. The classic symptoms of the disease have been well defined by the World Health Organization; however, olfactory/gustatory disorders have been reported in some studies, but there are still several missing points in the understanding and in the consensus about the clinical management of these cases. OBJECTIVE: To identify evidence in the scientific literature about olfactory/gustatory disorders, their clinical presentation, prevalence and possible specific treatments associated with COVID-19. METHODS: A systematic review of articles published up to April 25, 2020 was performed in Medline, Cochrane Clinical Trials, ScienceDirect, Lilacs, Scopus and Google Schoolar, OpenGrey.eu, DissOnline, The New York Academy of Medicine and Reasearch Gate. INCLUSION CRITERIA: (1) Studies on patients with COVID-19; (2) Records of COVID-19 signs/symptoms, and olfactory/gustatory functions. EXCLUSION CRITERIA: (1) Studies on non-human coronavirus; (2) Review articles; (3) Experimental studies (in animals or in vitro); (4) Olfactory/gustatory disorders initiated prior to SARS-CoV-2 infection. The risk assessment of bias of the selected studies was performed using the Newcastle-Ottawa scale. RESULTS: Six articles from the 1788 records met the inclusion criteria and were analyzed. A total of 1457 patients of different ethnicities were assessed; of them, 885 (60.7%) and 822 (56.4%) had smell and taste disorders, respectively, with women being most often affected. There were olfactory/gustatory disorders even without nasal obstruction/rhinorrhea and beginning even before the signs/symptoms of COVID-19; the recovery of smell/taste, when it occurs, usually happened in the first two weeks after COVID-19 resolution. There is evidence that olfactory/gustatory disorders are strong predictors of infection by SARS-CoV-2, and it is possible to recommend patient isolation, as early as of the medical consultation, preventing the spread of the virus. No scientific evidence has been identified for effective treatments for any of the disorders. CONCLUSION: Olfactory/gustatory disorders may occur at varying intensities and prior to the general symptoms of COVID-19 and should be considered as part of the clinical features of COVID-19, even in mild cases. There is still no scientific evidence of specific treatments for such disorders in COVID-19 disease.

Variability patterns and positively selected sites at the gametophytic self-incompatibility pollen SFB gene in a wild self-incompatible Prunus spinosa (Rosaceae) population.

Current models for the generation of new gametophytic self-incompatibility specificities require that neutral variability segregates within specificity classes. Furthermore, one of the models predicts greater ratios of nonsynonymous to synonymous substitutions in pollen than in pistil specificity genes. All models assume that new specificities arise by mutation only. To test these models, 21 SFB (the pollen S-locus) alleles from a wild Prunus spinosa (Rosaceae) population were obtained. For seven of these, the corresponding S-haplotype was also characterized. The SFB data set was also used to identify positively selected sites. Those sites are likely to be the ones responsible for defining pollen specificities. Of the 23 sites identified as being positively selected, 21 are located in the variable (including a new region described here) and hypervariable regions. Little variability is found within specificity classes. There is no evidence for selective sweeps being more frequent in pollen than in pistil specificity genes. The S-RNase and the SFB genes have only partially correlated evolutionary histories. None of the models is compatible with the variability patterns found in the SFB and the S-haplotype data.

Efficacy of Listerine Antiseptic in reducing viral contamination of saliva.

AIM: The anti-viral efficacy of oral antimicrobial rinses has not been adequately studied in terms of potential clinical significance. As a follow-up to an in vitro study on the effect of oral antiseptics on Herpes simplex virus, Type 1, this study was undertaken to evaluate the in vivo effect of an essential oil containing oral antiseptic on the reduction of viral titer in saliva during active viral infection. METHOD: Patients were recruited and evaluated in a single visit protocol at the onset of a perioral outbreak, consistent historically and clinically with recurrent Herpes labialis. Direct immunofluorescence of cytological smears of the lesions/oral fluids was used to confirm Herpes simplex virus types I or II. Patients were randomly assigned to one of two treatment groups: (1) active ingredient and (2) sterile water control. The viral lesion was evaluated as to clinical stage according to standard protocol. Salivary fluid samples were taken: (1) at baseline; (2) immediately following a 30 s rinse; (3) 30 min. after the 30 s rinse; and (4) on the repeat trial, also at 60 min. after the 30 s rinse. All samples were evaluated for viral titer and results compared. RESULTS: In Trial 1, the sample population consisted of 19 males and 21 females with an average age of 29.2 and in Trial 2, 21 males, 19 females with an average age of 28. In both Trials 1 and 2, recoverable infectious virions were reduced to zero after a 30 s experimental rinse; whereas, the control rinse resulted in a non-significant (p>0.05) reduction. The experimental group also demonstrated a continued significant (p<0.05) reduction 30 min. post rinse when compared with baseline while the control group returned to baseline levels. In Trial 2, the 60 min. post rinse follow-up demonstrated a 1-2 log residual reduction from baseline in the experimental group; however, this was not significant. CONCLUSIONS: There is clinical efficacy in utilizing an oral rinse with the antimicrobial agent Listerine Antiseptic in reducing the presence of viral contamination in oral fluids for at least 30 min. after oral rinse. The risk of viral cross contamination generated from these oral fluids in person to person contact or during dental treatment may be reduced.