Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19–79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (−79.7 ± 28.7, mean ± standard deviation), taste (−69.0 ± 32.6), and chemesthetic (−37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms.

In a preregistered, cross-sectional study, we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0–100 visual analog scales (VAS) for participants reporting a positive (C19+; n = 4148) or negative (C19−; n = 546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19− groups exhibited smell loss, but it was significantly larger in C19+ participants (mean ± SD, C19+: −82.5 ± 27.2 points; C19−: −59.8 ± 37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC = 0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0–10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4 < OR < 10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable.

Honey is an important food for man and has been used as a natural sweetener since ancient times. It is a viscous and aromatic product made by honey bees using the nectar of flowers or honeydew. Honey is composed of a complex mixture of carbohydrates and other substances such as organic acids, amino acids, proteins, minerals, vitamins, lipids, aroma compounds, flavonoids, pigments, waxes, pollen grains, several enzymes, and other phytochemicals. This chapter presents some properties of Apis mellifera honey as well as the main methods of honey analysis. All methods are based on specialized literature, including the Codex Alimentarius, AOAC, and publications of the International Honey Commission. Herein, we describe methods related to honey authenticity, botanical origin, geographical origin, physicochemical analysis, radioentomology, pesticide and antibiotic contamination, chemotherapeutics, and sensory analysis. All methods are described in a step-by-step model in order to facilitate their use. La miel es un alimento importante para el hombre y se ha utilizado como edulcorante natural desde la antigüedad. Es un producto viscoso y aromático hecho por las abejas de la miel usando el néctar de las flores o el rocío de miel. La miel está compuesta por una mezcla compleja de carbohidratos y otras sustancias como ácidos orgánicos, aminoácidos, proteínas, minerales, vitaminas, lípidos, compuestos aromáticos, flavonoides, pigmentos, ceras, granos de polen, varias enzimas y otros fitoquímicos. En este capítulo se presentan algunas propiedades de la miel de Apis mellifera, así como los principales métodos de análisis de la miel. Todos los métodos se basan en literatura especializada, incluido el Codex Alimentarius, AOAC y publicaciones de la Comisión Internacional de la Miel. A continuación, describimos métodos relacionados con la autenticidad de la miel, el origen botánico, el origen geográfico, el análisis fisicoquímico, la radioentomología, la contaminación por pesticidas y antibióticos, la quimioterapia y el análisis sensorial. Todos los métodos se describen en un modelo paso a paso para facilitar su uso.